[ { "id": "authors:w4snq-z7v36", "collection": "authors", "collection_id": "w4snq-z7v36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160401-101329099", "type": "article", "title": "Crevasses, Rocks and Huskies in Greenland: My introduction to geology in the 1950s", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Greenland became a semiautonomous part of the Danish Kingdom in 1953, having been a Danish colony since 1851. In 1950, when this story began, Greenland's population was only about 24,000, of whom perhaps 1,000 were Europeans \u2013 mainly Danes. The natives are a mixed European-Eskimo race, and many of them still followed the Eskimo way of life; they are called Greenlanders. Fishing, shrimping, sealing, and mining are the main economic activities. Most of people live on the west coast, there being only two settlements on the east coast where the pack-ice drifting from the north has been an effective barrier to ships and people.", "publisher": "Geoplanet Press", "publication": "Tales of Earth Science", "publication_date": "2008-12", "series_number": "1", "volume": "1", "issue": "1", "pages": "24-38" }, { "id": "authors:c1krb-ppm76", "collection": "authors", "collection_id": "c1krb-ppm76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160108-135751915", "type": "article", "title": "Presentation of the Roebling Medal for 2006 of the Mineralogical Society of America to W. Gary Ernst", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "President John Valley, members of the society, and guests:\nI am really delighted to have this opportunity to introduce\nGary Ernst for the Roebling Medal, 25 years after he was our\nPresident handing out these awards.\nFirst, I emphasize that it is no surprise to find Gary up\nhere today. The only surprise is that it didn't happen sooner.\nAnyone brave enough to tackle the experimental synthesis and\nphase relationships of amphiboles for his Ph.D. thesis in 1959\ndeserves the Roebling Medal. In fact, it earned him the MSA\nAward in 1969.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2007-05", "series_number": "5-6", "volume": "92", "issue": "5-6", "pages": "977-978" }, { "id": "authors:gqj67-ncx03", "collection": "authors", "collection_id": "gqj67-ncx03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160111-152014508", "type": "article", "title": "Joseph V. Smith 1928\u20132007 [Obituary]", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Joseph V. Smith was born on the 30th of July 1928, in Derbyshire, England. He married Brenda Wallis at Crich, Derbyshire, on the 31st of August, 1951, moved to the USA, and their family grew with two daughters, Virginia and Susan. He retired in September 2005 as the Louis Block Professor Emeritus in Geophysical Sciences and the College at the University of Chicago. On Friday the 6th of April, 2007, at age 78, he died of pneumonia at Beth Israel Deaconess Medical Center in Boston. Parkinson's disease had begun to take its cruel toll about five years earlier. He and his wife Brenda moved to Brookline in 2005 to be near their daughter, Virginia, and family, where he suffered a broken hip and several heart attacks before the final event. In the meantime, he continued to write an autobiographical book Living Safely which dealt with local and global problems facing our species. As Brenda said: \"He was very strong and very stoic. He handled any difficulties in life the way he handled his illness.\"", "issn": "0026-461X", "publisher": "Mineralogical Society", "publication": "Mineralogical Magazine", "publication_date": "2007-02", "series_number": "1", "volume": "71", "issue": "1", "pages": "113-119" }, { "id": "authors:v7cya-8se25", "collection": "authors", "collection_id": "v7cya-8se25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160108-135329401", "type": "article", "title": "Presentation of the Distinguished Public Service Medal of the Mineralogical Society of America for 2005 to Robin Brett", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mr. President, members of the society, and guests:\nIt is my pleasure to present Robin Brett for the Distinguished\nPublic Service Medal of our Mineralogical Society of America.\nThere is a remarkably close match between his lifetime of Public\nService efforts, and a section in the \"Description of the Award\"\nthat species: \"extraordinary service to national or international\nscience societies.\"\nThis nomination is inspired by Robin's repeated and continuing\nexcursions into national and international science with public\nramifications, including NASA, NSF, AGU, IUGG, GSA, IGC,\nIUGS, USGS, and ICSU, where he has served us all in vigorous\nstyle. I should add that while pursuing a career with the\nUSGS and NASA, Robin has produced a publication list that\nalso establishes his credentials as a distinguished mineralogist\nand geochemist.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2006-05", "series_number": "5-6", "volume": "91", "issue": "5-6", "pages": "973-974" }, { "id": "authors:9gv1b-kgc40", "collection": "authors", "collection_id": "9gv1b-kgc40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160108-135021977", "type": "article", "title": "Presentation of the Roebling Medal of the Mineralogical Society of America for 2002 to Werner Schreyer", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mr. President, distinguished mineralogists, and guests, I was\ndelighted when Werner Schreyer asked me to be his citationist,\nbecause I admire him for his scholarship, for his dogged pursuit\nof the perfect experiment seeking exquisite minerals, and\nfor his application of experimental mineralogy to petrological\nproblems. Werner and I have had parallel lives in experimental\npetrology, following paths that have converged from time to\ntime, and with each convergence has come growing respect\nand friendship. But as a schoolboy in the 1940s, I hated Werner\nSchreyer, and I'm sure that he hated me. We were receiving\nbombs from our respective air forces in Germany and England,\nand wartime propaganda is a powerful opinion-shaper. One of\nthe exercises in my school's Air Training Corps was aircraft\nrecognition, identifying the silhouettes of German aircraft, and\nWerner probably was expert in the same exercise as a member\nof the \"Hitlerjugend\".", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2003-05", "series_number": "5-6", "volume": "88", "issue": "5-6", "pages": "936-937" }, { "id": "authors:aeg8d-bmr93", "collection": "authors", "collection_id": "aeg8d-bmr93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-160635304", "type": "article", "title": "Acceptance of the Roebling Medal of the Mineralogical Society of America for 2001", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mr. President, members of the Society, and guests:\nI am deeply conscious of the honor involved in receiving\nthis Medal, and I thank the Committee and the Council for their\ndecision, which is always a difficult one. And I thank you, Art\nMontana, for your generous introduction\nIt is very satisfying to have the research generated in my\nlaboratory by more than 20 students and 20 research associates\nrecognized in this way. I wish that I had space here to acknowledge\nthem individually for their contributions\u2014without their\nenthusiasm, dedication, and polished finger-tips, ideas would\nnot have been translated into experiments, nor experiments\nconverted into phase diagrams, and phase diagrams would not\nhave been interpreted into petrological processes. They all deserve\na share of the Medal, and none more that \"Art the dart,\"\nwho had my lab buzzing loudest during his period with me,\nabout 35 years ago. I must also thank NSF for starting me off\nwith a laboratory as soon as I knew how to write a proposal,\nand for the years of support since then. The NSF policy of giving\nyoung scientists early independence is a great strength of\nour community.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2002-05", "series_number": "5-6", "volume": "87", "issue": "5-6", "pages": "790-793" }, { "id": "authors:j5r9h-9tn87", "collection": "authors", "collection_id": "j5r9h-9tn87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111209-135629440", "type": "article", "title": "Volatile Components, Magmas, and Critical Fluids in Upwelling Mantle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Ryabchikov", "given_name": "Igor D.", "clpid": "Ryabchikov-I-D" } ], "abstract": "The phase diagram for lherzolite\u2013CO_2\u2013H_2O provides a framework for interpreting the distribution of phase assemblages in the upper mantle with various thermal structures, in different tectonic settings. Experiments show that at depths >80 km, the near-solidus partial melts from lherzolite\u2013CO_2\u2013H_2O are dolomitic, changing through carbonate\u2013silicate liquids with rising temperatures to mafic liquids; vapor, if it coexists, is aqueous. Experimental data from simple systems suggest that a critical end-point (K) occurs on the mantle solidus at an undetermined depth. Isobaric (T\u2013X) phase diagrams for volatile-bearing systems with K elucidate the contrasting phase relationships for lherzolite\u2013CO_2\u2013H_2O at depths below and above a critical end-point, arbitrarily placed at 250 km. At levels deeper than K, lherzolite can exist with dolomitic melt, aqueous vapor, or with critical fluids varying continuously between these end-members. Analyses of fluids in microinclusions of fibrous diamonds reveal this same range of compositions, supporting the occurrence of a critical end-point. Other evidence from diamonds indicates that the minimum depth for this end-point is 125 km; maximum depth is not constrained. Constructed cross-sections showing diagrammatically the phase fields intersected by upwelling mantle indicate how rising trace melts may influence trace element concentrations within a mantle plume.", "doi": "10.1093/petrology/41.7.1195", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "2000-07", "series_number": "7", "volume": "41", "issue": "7", "pages": "1195-1206" }, { "id": "authors:a0q9a-we981", "collection": "authors", "collection_id": "a0q9a-we981", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-152036575", "type": "article", "title": "Calciocarbonatite and magnesiocarbonatite rocks and magmas represented in the system CaO-MgO-CO_2-H_2O at 0.2 GPa", "author": [ { "family_name": "Lee", "given_name": "W.-J.", "clpid": "Lee-W-J" }, { "family_name": "Fanelli", "given_name": "M. F.", "clpid": "Fanelli-M-F" }, { "family_name": "Cava", "given_name": "N.", "clpid": "Cava-N" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The low-pressure eutectic for the coprecipitation of calcite, portlandite, and periclase/brucite (with H_2O-rich vapor) has served as a model for the existence and crystallization of carbonatite magmas. Attempts to determine conditions for the appearance of dolomite at this eutectic have been unsuccessful. We have discovered a second low-temperature eutectic for more magnesian liquids which excludes portlandite and includes dolomite (all results are vapor-saturated). Addition of Ca(OH)_2-Mg(OH)_2 to CaCO_3-MgCO_3 at 0.2\u2009GPa depresses the liquidus to temperatures below the crest of the calcite-dolomite solvus; the vapor-saturated liquidus surface falls steeply, and the field boundary for liquids coexisting with calcite and periclase reaches a peritectic at 880\u2009\u00b0C, where a narrow field for liquidus dolomite begins, extending down to the eutectic at 659\u2009\u00b0C for the coprecipitation of calcite, dolomite and periclase (brucite should replace periclase at slightly higher pressures). The calcite liquidus is very large. The field boundary for coexistence of calcite and dolomite extends approximately in the direction from CaMg(CO_3)_2 towards Mg(OH)_2. The results illustrate conditions for the formation of mineral-specific cumulates from variable magma compositions. Hydrous (or sodic) carbonate-rich liquids with compositions from CaCO_3 to CaMg(CO_3)_2 will precipitate calcite-carbonatites first, followed by calcite-dolomite-carbonatites, with the prospect of precipitating dolomite-carbonatite alone through a limited temperature interval, and with periclase joining the assemblage in the closing stages. Periclase in the Fe-free system may represent the ubiquitous occurrence of magnetite in natural carbonatites. The restricted range for the precipitation of dolomite-carbonatites adds credibility to the evidence for primary magnesiocarbonatite (near-dolomite composition) magmas. Magnesiocarbonatite magmas can precipitate much calcite-carbonatite rock.", "doi": "10.1007/s007100050011", "issn": "0930-0708", "publisher": "Springer", "publication": "Mineralogy and Petrology", "publication_date": "2000-04", "series_number": "4", "volume": "68", "issue": "4", "pages": "225-256" }, { "id": "authors:8b49t-dzf68", "collection": "authors", "collection_id": "8b49t-dzf68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-142051569", "type": "article", "title": "Melts in the mantle modeled in the system CaO-MgO-SiO_2-CO_2 at 2.7 GPa", "author": [ { "family_name": "Lee", "given_name": "W. J.", "clpid": "Lee-W-J" }, { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P.", "clpid": "Wyllie-P-J" } ], "abstract": "The effect of CO_2 on mantle peridotites is modeled by experimental data for the system CaO-MgO-SiO_2-CO_2 at 2.7\u2009GPa. The experiments provide isotherms for the vapor-saturated liquidus surface, bracket piercing points for field boundaries on the surface, and define the positions and compositions of isobaric invariant liquids on the boundaries (eutectics and peritectics). CO_2-saturated carbonatitic liquids (>80% carbonate) exist through approximately 200\u2009\u00b0C above the solidus, with a transition to silicate liquids (>80% silicate) within \u223c75\u2009\u00b0C across a plateau on the liquidus. Carbonate-rich magmas cannot cross the silicate-carbonate liquidus field boundary, so the carbonate liquidus field is therefore a forbidden volume for liquid magmas. This confirms the fact that rounded, pure carbonates in mantle xenoliths cannot represent original liquids. A P-T diagram is constructed for the carbonation and melting reactions for mineral assemblages corresponding to lherzolite, harzburgite, websterite and wehrlite, with carbonate, CO_2 vapor (V), or both. The changing compositions of liquids in solidus reactions on the P-T diagram are illustrated by the changing compositions of eutectic and peritectic liquids on the liquidus surface. At an invariant point Q (\u223c2.8\u2009GPa/1230\u2009\u00b0C), all peridotite assemblages coexist with a calcite-dolomite solid solution (75\u2009\u00b1\u20095% CaCO_3) and a dolomitic carbonatite melt [57% CaCO_3 (CC), 33% MgCO_3 (MC), 10% CaMgSi_2O_6 (Di)], with 63% CC in the carbonate component. At higher pressures, dolomite-lherzolite, dolomite-harzburgite-V, and dolomite-websterite-V melt to yield similar liquids. Magnesian calcite-wehrlite is the only peridotite melting to carbonatitic liquids (more calcic) at pressures below Q (\u223c70\u2009km). Dolomitic carbonatite magma rising through mantle to the near-isobaric solidus ledge near Q will begin to crystallize, releasing CO_2 (enhancing crack propagation), and metasomatizing lherzolite toward wehrlite.", "doi": "10.1007/s004100050557", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "2000-03", "series_number": "3", "volume": "138", "issue": "3", "pages": "199-213" }, { "id": "authors:7z1m7-c2z02", "collection": "authors", "collection_id": "7z1m7-c2z02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-143855977", "type": "article", "title": "The system CaO-MgO-SiO_2-CO_2 at 1 GPa, metasomatic wehrlites, and primary carbonatite magmas", "author": [ { "family_name": "Lee", "given_name": "W. J.", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "New experimental data in CaO-MgO-SiO_2-CO_2 at 1\u2009GPa define the vapor-saturated silicate-carbonate liquidus field boundary involving primary minerals calcite, forsterite and diopside. The eutectic reaction for melting of model calcite (1% MC)-wehrlite at 1\u2009GPa is at 1100\u2009\u00b0C, with liquid composition (by weight) 72% CaCO_3 (CC), 9% MgCO_3 (MC), and 18% CaMgSi_2O_6 (Di). These data combined with previous results permit construction of the isotherm-contoured vapor-saturated liquidus surface for the calcite/dolomite field, and part of the adjacent forsterite and diopside fields. Nearly pure calcite crystals in mantle xenoliths cannot represent equilibrium liquids. We recently determined the complete vapor-saturated liquidus surface between carbonates and model peridotites at 2.7\u2009GPa; the peritectic reaction for dolomite (25% MC)-wehrlite at 2.7\u2009GPa occurs at 1300\u2009\u00b0C, with liquid composition 60% CC, 29% MC, and 11% Di. The liquidus field boundaries on these two surfaces provide the road-map for interpretation of magmatic processes in various peridotite-CO_2 systems at depths between the Moho and about 100\u2009km. Relationships among kimberlites, melilitites, carbonatites and the liquidus phase boundaries are discussed. Experimental data for carbonatite liquid protected by metasomatic wehrlite have been reported. The liquid trends directly from dolomitic towards CaCO_3 with decreasing pressure. The 1.5\u2009GPa liquid contains 87% CC and 4% Di, much lower in silicate components than our phase boundary. However, the liquids contain approximately the same CaCO_3 (90\u2009\u00b1 1\u2009wt%) in terms of only carbonate components. For CO_2-bearing mantle, all magmas at depth must pass through initial dolomitic compositions. Rising dolomitic carbonatite melt will vesiculate and may erupt as primary magmas through cracks from about \u02dc70\u2009km. If it percolates through metasomatic wehrlite from 70\u2009km toward the Moho at 35\u201340\u2009km, primary calcic siliceous carbonatite magma can be generated with silicate content at least 11\u201318% (70\u201340\u2009km) on the silicate-carbonate boundary.", "doi": "10.1007/s004100050558", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "2000-03", "series_number": "3", "volume": "138", "issue": "3", "pages": "214-228" }, { "id": "authors:xq7zt-t8z25", "collection": "authors", "collection_id": "xq7zt-t8z25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-150953411", "type": "article", "title": "Experimental determination of composition dependence of hydrous silicate melts on sulfate solubility", "author": [ { "family_name": "Ducea", "given_name": "Mihai N.", "orcid": "0000-0002-5322-0782", "clpid": "Ducea-M-N" }, { "family_name": "McInnes", "given_name": "Brent I. A.", "clpid": "McInnes-B-I-A" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We measured the solubility of SO_3 in quartz-normative and nepheline-normative compositions in\nthe system Na_2O-Al_2O_3-SiO_2-H_2O at temperatures from 800-825 \u00b0C and pressures between 1.5-1.7 kbar. We\nadded 1.5, 3, 10 or 15 wt% CaSO_4 to two H_2O-saturated synthetic compositions near the eutectics in quartzalbite-H_2O and nepheline-albite-H_2O. The low sulfate solubilities measured in the quartz-normative quenched\nglasses (0.06-0.12% SO_3) are similar to previous determinations on quartz-normative melts from natural rock\ncompositions. The sulfate contents of quenched glasses in the nepheline-normative system are up to 6 times\nhigher (0.17-0.36 %SO_3). Precipitation of anhydrite in the quartz-normative melt requires addition of about 6\nwt% CaSO_4 at 800\u00b0C, and 10 wt% CaSO_4 at 820\u00b0C. In contrast, < 1.5 wt% CaSO_4 added to the nepheline-normative\nliquid is sufficient to cause precipitation of ha\u00fcyne or an immiscible sulfate-rich liquid. We conclude\nthat the sulfate solubility in hydrous magmas is significantly influenced by silica activity (melt alkalinity) and\nSiO_2 concentration in melts.", "doi": "10.1127/ejm/11/1/0033", "issn": "0935-1221", "publisher": "E. Schweizerbartsche Verlagsbuchhandlung", "publication": "European Journal of Mineralogy", "publication_date": "1999-02", "series_number": "1", "volume": "11", "issue": "1", "pages": "33-43" }, { "id": "authors:5vcn5-j8y85", "collection": "authors", "collection_id": "5vcn5-j8y85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-153104111", "type": "article", "title": "Model System Controls on Conditions for Formation of Magnesiocarbonatite and Calciocarbonatite Magmas from the Mantle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" } ], "abstract": "Experimental data indicate that carbonate-rich magmas may be generated at depths greate than \u223c70 km by partial melting of carbonated peridotite. The near-solidus magmas lie on the liquidus field boundary between silicates and carbonates. Liquid compositions are dominated by th system CaCO_3\u2013MgCO_3, and precise compositions (e.g. Ca/Mg) are define by the peridotite mineralogy (e.g. harzburgite, lherzolite, wehrlite); alkali contents reflect directly the peridotite composition. These liquids are dolomitic, with Ca/(Ca + Mg) between 0.7 and 0.5 from 2 GPa to at least 7 GPa. At conditions of mantle melting, there is a large separation between the silicate\u2013carbonate liquid immiscibility volume, the silicate\u2013carbonate liquidus field boundary, and probable liquid paths. The formation of carbonate-rich liquids immiscible with silicate magmas in the mantle is therefore unlikely, which denies the generation of immiscible CaCO_3 ocelli and primary natrocarbonatite magmas. Rising carbonate-rich magmas retaining equilibrium with mantle lherzolite will react, crystallize and release CO_2 vapor at depths of \u223c70 km, increasing clinopyroxene/orthopyroxene in the rock. Primary magnesiocarbonatite magmas (dolomitic) can be erupted explosively from this depth. Given sufficient magma, lherzolite can be converted to wehrlite by this decarbonation reaction. At shallower depths, wehrlite (but no other peridotite) can coexist with carbonatite magma relatively enriched in Ca/Mg. If metasomatism of lherzolite to wehrlite can occur through depth of tens of kilometers, our new data at 1 GPa confirm an earlier proposal that primary calciocarbonatite magmas can be generated at some depth between 70 km and 40 km, but indicate considerably higher silicate components. The shallowest magmas contain a maximum of 73 wt % CaCO_3 (equivalent to 89% CaCO_3 in the carbonate components of the liquid) with 18% silicate components at 1 GPa. Phase relations in the system CaO\u2013MgO\u2013CO_2\u2013H_2O show that magnesiocarbonatite magmas can precipitate s\u00f6vites (calciocarbonatite rocks).", "doi": "10.1093/petroj/39.11-12.1885", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1998-11", "series_number": "11-12", "volume": "39", "issue": "11-12", "pages": "1885-1893" }, { "id": "authors:czksv-jsk61", "collection": "authors", "collection_id": "czksv-jsk61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-130122340", "type": "article", "title": "Processes of Crustal Carbonatite Formation by Liquid Immiscibility and Differentiation, Elucidated by Model Systems", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental studies on several silicate\u2013carbonate joins provide a framework in the system CaO\u2013Na_2O\u2013(MgO + FeO)\u2013(SiO_2 + Al_2O_3) (+ CO_2) which illustrates possible processes for the formation of carbonatites. The two key features are the silicate\u2013carbonate liquidus surface, and the miscibility gap liquidus surface. Crystallizing parental carbonated silicate melts may reach a silicate\u2013CO_2 eutectic, a silicate\u2013carbonate field boundary, or a miscibility gap. Some hydrous carbonated silicate melts may bypass the high-temperature miscibility gap and reach the silicate\u2013carbonate field boundary. Immiscible carbonate-rich liquids in model systems simulating magmatic conditions tend to be concentrated near calciocarbonatite compositions (< \u223c80% CaCO_3; e.g. nepheline s\u00f6vite), but may be more alkalic from silicate parents with higher Na/Ca values. An immiscible carbonate-rich liquid separating from the high-temperature parent silicate liquid will cool with the precipitation of silicates only, until it reaches the silicate\u2013carbonate field boundary, where it is capable of precipitating carbonate minerals, which can form carbonatite cumulates. Some parents may reach this boundary by direct crystallization, but most probably traverse the miscibility gap. Along this field boundary, the coprecipitation of calcite drives the liquid toward residual alkali-rich compositions. The carbonate liquidus (>85% CaCO_3) is a 'forbidden volume' for magmas. Vapor loss from carbonatite magma can introduce alkalis into country rocks, but this does not cause alkali depletion of magma; calcite precipitates to maintain the magma composition. Hydrous magnesiocarbonatite magmas can precipitate cumulate s\u00f6vites.", "doi": "10.1093/petroj/39.11-12.2005", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1998-11", "series_number": "11-12", "volume": "39", "issue": "11-12", "pages": "2005-2013" }, { "id": "authors:m588m-wy718", "collection": "authors", "collection_id": "m588m-wy718", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160111-160545760", "type": "article", "title": "Hutton and Hall on theory and experiments: the view after 2 centuries", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The interplay between observation, theory and experiment\nfocused on the birth of geology as a science, during\nthe period of the Scottish Enlightenment. The fires of\nHutton's (1726\u20131797) Plutonists could not be quenched\nby the oceans of Werner's (1750\u20131817) Neptunists. Hall\n(1761\u20131832) was convinced that Hutton's \"Theory of\nthe Earth\" could be proved by experiments, but he\ndeferred to the fears of his older colleague that failed\nexperiments might discredit the Theory (which needed\nno further proof), and completed the experiments only\nafter Hutton's death. Hutton censured those who \"judge\nof the great operations of the mineral kingdom, from\nhaving kindled a fire, and looked into the bottom of a little\ncrucible.\" Hall believed that \"the imitation of the\nnatural process is an object which may be pursued with\nrational expectation of success.\" Following many discussions\nbetween Hutton and Hall, three topics were\npursued in Hall's experiments: 1790, the magmatic origin\nof granites, younger than schists; 1798, whinstones/\ndolerites are as magmatic as known lavas; 1805,\npowdered calcite is transformed to marble and melted\nby the effects of compression (and water) in modifying\nthe action of heat. The latter involved the first high-pressure,\nhigh-temperature apparatus and earned Hall the\ntitle \"Father of Experimental Petrology\". Subsequent\ndevelopment of these three topics is outlined, with particular\nreference to Scottish contributions, and to\ndebates about primary basalts, granitization, and carbonatites.", "issn": "0705-3797", "publisher": "International Union of Geological Sciences", "publication": "Episodes", "publication_date": "1998-03", "series_number": "1", "volume": "21", "issue": "1", "pages": "3-10" }, { "id": "authors:3gtjj-dh141", "collection": "authors", "collection_id": "3gtjj-dh141", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-131252697", "type": "article", "title": "Petrogenesis of Carbonatite Magmas from Mantle to Crust, Constrained by the System CaO-(MgO + FeO*)-(Na_2O + K_2O)-(SiO_2 + Al_2O_3 + TiO_2)-CO_2", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental results from the systems CaO\u2013MgO\u2013SiO_2\u2013CO_2, Na_2O\u2013CaO\u2013Al_2O_3\u2013SiO_2\u2013CO_2, and a primitive magnesian nephelinite mixed with carbonates have been combined for construction of phase diagrams for the pseudoquaternary system CaO\u2013(MgO + FeO*)\u2013(Na_2O + K_2O)\u2013(SiO_2 + Al_2O_3 + TiO_2) with CO_2 at 1.0 and 2.5 GPa pressure. These diagrams provide a petrogenetic framework for magmatic processes from mantle to deep crust, with particular reference to the melting products of carbonate peridotite and the paths of crystallization of carbonated silicate magmas toward carbonatite magmas, with or without the intervention of silicate\u2013carbonate liquid immiscibility. Three key features control these processes: (1) the liquidus surface bounding the silicate\u2013carbonate liquid miscibility gap, (2) the silicate\u2013carbonate liquidus boundary surface which separates the liquidus volume for primary silicates from that for primary carbonates, and (3) the curve of intersection of these two surfaces (1 and 2) which defines the coprecipitation of silicates and calcite with coexisting immiscible silicate- and carbonate-rich liquids. The geometrical arrangement of the two surfaces varies as a function of both pressure and bulk composition (e.g. with Si/Al, Na/K, Mg/Fe). Surface (2) is the locus of initial liquids from partial melting of carbonate\u2013silicate assemblages, and the limit for residual liquid compositions derived from silicate\u2013CO_2 liquids. The carbonate liquidus volume is a forbidden region for carbonate-rich magmas derived from silicate magmas at the pressures investigated. The immiscible liquids dissolve no more than 80 wt % CaCO_3, and the miscibility gap (MG) becomes smaller with increasing Mg/Ca. Extrapolation of experimental data indicates that the MG disappears with more than \u223c50 wt % (MgO + FeO*) at 1.0 GPa for the compositions investigated. The distance between the miscibility gap, surface (1), and the silicate\u2013carbonate liquidus surface, surface (2), increases significantly with increasing (MgO + FeO*). This observation, coupled with knowledge of the phase boundaries in the system, allows comparisons with projected rock compositions, and this permits the following conclusions. Calciocarbonatites and natrocarbonatites are excluded as candidates for primary magmas from the mantle, which must have compositions dominated by calcic dolomite. The formation of (equilibrium) carbonate-rich liquids immiscible with silicate magmas in the mantle is unlikely, which denies the formation of CaCO_3 ocelli in mantle xenoliths as immiscible liquids. Immiscible carbonate-rich magmas separated from many silicate magmas may tend to be concentrated near calciocarbonatite compositions, with maximum CaCO_3 75\u201380 wt %, low (MgO + FeO*), and (Na,K)_2CO_3 near 15 wt %. Silicate parents with higher Na/Ca and peralkalinity may yield immiscible magmas approaching natrocarbonatite compositions. Exsolution of immiscible carbonate-rich magma occurs without the coprecipitation of calcite except along the limiting field boundary (3). Only after the carbonate-rich magma is physically separated from the parent magma, and cooled with the precipitation of silicates, does it reach the silicate\u2013carbonate field boundary and precipitate cumulate carbonatites, with inevitable enrichment of residual liquids in alkalis. Calciocarbonatite magmas cannot be derived from natrocarbonatite magmas. Dolomitic carbonatite magmas cannot be formed by liquid immiscibility, but only by fractionation of calciocarbonatites (according to CaCO_3\u2013MgCO_3), or as primary magmas.", "doi": "10.1093/petroj/39.3.495", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1998-03", "series_number": "3", "volume": "39", "issue": "3", "pages": "495-517" }, { "id": "authors:vb7dy-v1n93", "collection": "authors", "collection_id": "vb7dy-v1n93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-085448593", "type": "article", "title": "The International Union of Geodesy and Geophysics, a US National Academy Report, and the view ahead", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The International Association of Hydrological Sciences (IAHS) is one of the seven international associations comprising the International Union of Geodesy and Geophysics (IUGG). Each Association has its own domain, but the boundaries between them are artificial. The Earth is undisciplined, and it does not recognize our academic subjects. In the US Academy Report \"Solid-Earth Sciences and Society\", published in 1993, a number of broad objectives and major research areas were set up in a matrix which provided a research framework. A remarkable number of high-priority research opportunities in the \"solid-Earth Sciences\" are concerned with water, the subject of IAHS. Water is a critical material for society and indeed in nearly every topic in Earth science research. Our priorities for the next century must be based on the beautiful science which arouse our curiosity, but we must also give weight to societal problems. Examples of burning recent problems can be found in many of the world's megacities that are situated in locations threatened by earthquakes, volcanic eruptions, landslides, floods, and rising sea level.", "doi": "10.1080/02626669809492100", "issn": "0262-6667", "publisher": "Taylor & Francis", "publication": "Hydrological Sciences Journal", "publication_date": "1998", "series_number": "1", "volume": "43", "issue": "1", "pages": "3-18" }, { "id": "authors:e5bmx-86k87", "collection": "authors", "collection_id": "e5bmx-86k87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-112604987", "type": "article", "title": "Liquid Immiscibility in the Join NaAlSiO_4-NaAlSi_3O_8-CaCO_3 at 1 GPa: Implications for Crustal Carbonatites", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The synthetic system Na_2O\u2013CaO\u2013Al_2O_3\u2013SiO_2\u2013CO_2 has been widely used as a model to show possible relationships among alkalic silicate magmas, calciocarbonatites, and natrocarbonatites. The determined immiscibility between silicate- and carbonate-rich liquids has been strongly advocated to explain the formation of natural carbonatite magmas. Phase fields intersected at 1.0 GPa by the composition joins NaAlSiO_3O_8\u2013CaCO_3 (Ab\u2013CC, published) and NaAlSiO_4(Ne)_(90)Ab_(10)\u2013CC (new), along with measured immiscible liquid compositions, provide pseudoternary phase relationships for the composition triangles Ab\u2013CC\u2013Na_2CO_3(NC) and Ne_(90)Ab_(10)\u2013CC\u2013NC. Interpolation between these, and extrapolation within the CO_2-saturated tetrahedron Al_2O_3\u2013SiO_2\u2013CaO\u2013Na_2O, provides pseudoquaternary phase relationships defining the volume for the miscibility gap and the surface for the silicate\u2013carbonate liquidus field boundary. The miscibility gap extends between 10 and 70 wt % CaCO_3 on the triangle Ne\u2013Ab\u2013CC at 1.0 GPa; it does not extend to the Na_2O-free side of the tetrahedron. The liquidus minerals in equilibrium with both silicate- and carbonate-rich consolute liquids are nepheline, plagioclase, melitite, and wollastonite; with increasing Si/Al the liquidus for calcite reaches the miscibility gap. We use these phase relationships to: (1) illustrate possible paths of crystallization of initial CO_2-bearing silicate haplomagmas, (2) place limits on the compositions of immiscible carbonatite magmas which can be derived from silicate parent magmas, and (3) illustrate paths of crystallization of carbonatite magmas. Cooling silicate\u2013CO_2 liquids may reach the miscibility gap, or the silicate\u2013calcite liquidus field boundary, or terminate at a eutectic precipitating silicates and giving off CO_2. Silicate\u2013CO_2 liquids can exsolve liquids ranging from CaCO_3\u2013rich to alkalic carbonate compositions. There is no basis in phase relationships for the occurrence of calciocarbonatite magmas with \u223c99 wt % CaCO_3; carbonate liquids derived by immiscibility from a silicate\u2013CO_2 parent (at crustal pressures) contain a maximum of 80 wt % CaCO_3. There are two relevant paths for a silicate liquid which exsolves carbonate-rich liquid (along with silicate mineral precipitates): (1) the assemblage is joined by calcite, or (2) the assemblage persists without carbonate precipitation until all silicate liquid is used up. The phase diagrams indicate that high-temperature immiscible carbonate-rich liquids must be physically separated from parent silicate liquid before they can precipitate carbonate-rich mineral assemblages. Path (1) then corresponds to the silicate\u2013calcite liquidus field boundary, and a stage is reached where the carbonate\u2013rich liquids will precipitate large amounts of calcite and fractionate toward alkali carbonates (not necessarily matching natrocarbonatite compositions). In path (2) the high-temperature immiscible carbonate liquid precipitates only silicates through a temperature interval until it reaches the silicate\u2013carbonate liquidus field boundary, where it may precipitate calcite or nyerereite or gregoryite. S\u00f6vites are readily explained as cumulates, with residual alkali-rich melts causing fenitization. We can see no way in phase diagrams for vapor loss to remove alkalis and change immiscible natrocarbonatite liquids to CaCO_3\u2013rich liquids; adjustments to vapor loss would be made not by change in liquid composition but by precipitation of calcite and silicate minerals. The processes illustrated in this model system are applicable to a wide range of magmatic conditions, and they complement and facilitate interpretation of phase relationships in the single paths represented by each whole- rock phase euilibrium study.", "doi": "10.1093/petroj/38.9.1113", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1997-09", "series_number": "9", "volume": "38", "issue": "9", "pages": "1113-1135" }, { "id": "authors:wp5ba-rtz14", "collection": "authors", "collection_id": "wp5ba-rtz14", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-082914770", "type": "article", "title": "Liquid immiscibility between nephelinite and carbonatite from 1.0 to 2.5 GPa compared with mantle melt compositions", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "In order to define the conditions for the formation of immiscible carbonatite magmas in the lithosphere and in the crust, we have conducted phase equilibrium experiments to determine the effect of pressure and temperature on the silicate-carbonate liquid miscibility gap in bulk compositions appropriate for magmas in the upper mantle. A primitive (magnesian) nephelinite (NEPH) was used as a starting material, mixed with carbonates. Experiments were made with mixtures in the joins NEPH-dolomite-Na_2CO_3 (NEPH-Dol-NC) at 1.0 to 2.5\u2009GPa, and NEPH-calcite (NEPH-CC) at 1.0\u2009GPa. The miscibility gap was intersected by the join NEPH-Dol-NC (liquids with olivine), but not by NEPH-CC. Together with previous results for the Mg-free system (Na_2O-CaO-Al_2O_3-SiO_2-CO_2), it was established that the size of the miscibility gap for magnesian compositions increases with decreasing pressures from depths of ~100 km to ~35 km; it increases further as compositions are changed by decreasing Mg/Ca. The maximum CaCO_3 in liquids associated with the miscibility gap is 50 wt\u200a% for Mg-bearing liquids, and 80 wt\u200a% for Mg-free liquids. There is no experimental evidence for nearly pure-CaCO_3 immiscible liquids, but abundant evidence for the precipitation of rounded calcite crystals from carbonate-rich liquids. The join NEPH-CC locates a piercing point on the liquidus field boundary for coprecipitation of olivine and calcite at NEPH_(50)CC_(50) (wt\u200a%), part of the silicate-carbonate liquidus field boundary which defines the locus of liquids formed from carbonate-peridotites. The miscibility gap results are compared with magmas formed during partial fusion of CO_2-bearing mantle peridotites, and during fractional crystallization of mantle-derived magmas. None of the probable magma paths in mantle processes intersects the miscibility gap. CO_2-bearing mantle-derived alkalic magmas such as nephelinites and melilitites may fractionate during uprise through the mantle and crystallization within the crust. The compositions of these evolved nephelinites and phonolites approach the silicate side of the miscibility gap, confirming the probable generation of immiscible, alkalic carbonate-rich liquids at crustal pressures.", "doi": "10.1007/s004100050261", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1997-03", "series_number": "1-2", "volume": "127", "issue": "1-2", "pages": "1-16" }, { "id": "authors:88538-jjz91", "collection": "authors", "collection_id": "88538-jjz91", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-110404222", "type": "article", "title": "Liquid Immiscibility in the Join NaAlSi_3O_8\u2212CaCO_3 to 2.5 GPa and the Origin of Calciocarbonatite Magmas", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Field evidence from intrusive and effusive carbonatites supports the existence of calciocarbonatite magmas. Published experimental evidence in the model system Na_2O\u2212CaO\u2212Al_2O_3\u2212SiO_2\u2212CO_2 indicated the formation of nearly pure (99%) CaCO_3 immiscible liquids from a carbonated silicate liquid. This evidence has been used to support interpretations of extremely CaCO_3-rich calciocarbonatite magmas, and immiscible liquids with compositions of almost pure CaCO_3 in metasomatized mantle peridotite and eclogite. Detailed phase relationships are constructed in the model system, based on phase fields intersected by the join NaAlSi_3O_8\u2212CaCO_3 (Ab-CC) at 1.0, 1.5, and 2.5 GPa between 1100 and 1500\u00b0C, and analyzed immiscible liquids. The miscibility gap between silicate-rich liquid and carbonate-rich liquid intersected by the join Ab-CC contracts considerably with decreasing pressure: 2.5 GPa, between Ab_(10)CC_(90) (by wt%) and Ab_(65)CC_(35) above 1310\u00b0C; 1.5 GPa, between Ab_(23)CC_(77) and Ab_(43)CC_(57) above 1285\u00b0C; 1.0 GPa, not intersected. The liquidus piercing point between calcite and silicates becomes enriched in CaCO_3 with decreasing pressure, from Ab_(80)CC_(20) at 2.5 GPa to Ab_(47)CC_(53) at 1.0 GPa. No immiscible liquid contains more than \u223c80% dissolved CaCO_3, and all contain at least 5% Na_2CO_3. A round CaCO_3 phase exhibiting morphology similar to that displayed by immiscible liquid globules is determined to be crystalline calcite under experimental conditions. The topology of the phase fields and field boundaries illustrates the kinds of processes and controls existing in magmatic systems. Calciocarbonatite magmas cannot be produced by equilibrium immiscibility process in the mantle. Carbonated silicate magmas in the crust yield residual calciocarbonatite magmas by fractionation along the silicate-calcite field boundary, reached either directly from the silicate liquidus or more commonly via the miscibility gap. Immiscible carbonaterich magmas when freed from the silicate parent cool down a sleep silicate liquidus until they reach a silicate-carbonate field boundary. There is no experimental evidence for immiscible calciocarbonatite magmas with > 80% CaCO_3, and calcite lapilli cannot be formed from 99% CaCO_3 magmas. Sovites are surely cumulates.", "doi": "10.1093/petrology/37.5.1125", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1996-10", "series_number": "5", "volume": "37", "issue": "5", "pages": "1125-1152" }, { "id": "authors:ypgkz-4f287", "collection": "authors", "collection_id": "ypgkz-4f287", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160111-152433080", "type": "article", "title": "Experimental petrology of upper mantle materials, processes and products", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experiments on rock materials and volatile components provide an array of phase equilibrium boundaries, giving the depth-temperature framework for the phase transitions experienced by rock masses as they move up or down within the Earth in response to the dynamic processes of mantle convection and plate tectonics. Sub-solidus phase transitions in mantle materials correlate well with upper mantle structure determined from seismic studies, but debate continues about whether there is a change in composition at some seismic boundaries. The interface at 650 km correlates with the transformation of most minerals into the perovskite structure, which may have significant effects on mantle dynamics. Recent research on mantle xenoliths has been concerned with extension of standard thermometers and barometers to higher pressures and their practical assessment, along with the development and refinement of new geothermobarometers. The experimental partial melting of mantle peridotite has been elucidated by detailed studies of model systems and new experimental techniques. Parameterization of the data makes prediction possible. The origin of MORBs involves a complex process of fractional fusion. Evidence from static olivine flotation experiments and shock wave compression experiments on molten komatiite indicates that the densities of mantle melts may exceed that of the residual rock at depths greater than 400 km, which would prohibit ascent of the magma. Recent investigations have identified many dense hydrous magnesian silicates (DHMS), stable through the upper mantle between ~ 300 and 650 km, and reaching the peridotite-volatile solidus curve through part of this interval. The near-solidus liquid composition in peridotite-CO_2-H_2O above ~ 2 GPa is carbonatitic (calcic dolomite), potentially a powerful agent for metasomatism. Experimental studies of trace element distributions between mantle minerals and carbonatitic liquids are beginning to permit quantification. Determination of the effect of reduced oxygen fugacity has introduced mantle scenarios with melting induced by redox changes There is indirect experimental evidence that the solidus may terminate at a critical end-point at depths of a few hundred kilometers. Recent experiments related to subduction of oceanic crust include measurements of liquid composition from the melting of H_2O-undersaturated peridotite, the vapour-absent melting of amphibolite, and partial melting of pelagic clays. Much H_2O is expelled during subduction, but the current estimates of low temperatures support the deep subduction and longterm storage in the mantles of both H_2O and CO_2.", "doi": "10.1016/0264-3707(95)00023-3", "issn": "0264-3707", "publisher": "Elsevier", "publication": "Journal of Geodynamics", "publication_date": "1995-12", "series_number": "4", "volume": "20", "issue": "4", "pages": "429-468" }, { "id": "authors:5rrr4-8d897", "collection": "authors", "collection_id": "5rrr4-8d897", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-134311354", "type": "article", "title": "Liquid segregation parameters from amphibolite dehydration melting experiments", "author": [ { "family_name": "Wolf", "given_name": "Michael B.", "clpid": "Wolf-M-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We have experimentally obtained some of the parameters necessary for understanding the segregation of silicate liquid from amphibolite undergoing dehydration melting at 1 GPa and 750\u20131000\u00b0C. The solidus for this calcic amphibolite (68% Mg-Hb, 32% Pl (An_(90))) is <750\u00b0C. Amphibolites begin to melt at relatively high temperatures in the garnet-absent field, but the solidus appears to backbend at \u223c1 GPa, coincident with the garnet-in boundary. Hornblende breakdown due to garnet formation releases H_2O and causes melting. Thus, in the garnet-present field (\u22651 GPa), the amphibolite dehydration melting solidus may be coincident with the H_2O-saturated solidus. Liquid interconnectivity may be achieved at <900\u00b0C and <5 vol % liquid, based on both physical and chemical data from solid rock runs. Mass balance calculations from powdered rock runs suggest that small amounts (\u223c5\u201315 vol %) of hydrous (\u22654 wt % H_2O), low-viscosity (10^3\u201310^4 Pa s), heavy rare earth element-depleted, felsic liquid may be segregated during amphibolite dehydration melting at \u2265875\u00b0C. The rapid breakdown of coarse-grained Hb cores may lead to the formation of transient H_2O-saturated liquids with even lower viscosities (\u223c10^2 Pa s). Although comprising only a small portion of the melting cycle, these H_2O-rich conditions may enhance the segregation of liquid by reduction of liquid viscosities and by mechanical effects on the restite (e.g., increased deformation and liquid fracturing). During anatexis of coarse-grained (natural) rocks, transient conditions may control the initial stages of liquid segregation.", "doi": "10.1029/95JB00660", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research B", "publication_date": "1995-08-10", "series_number": "B8", "volume": "100", "issue": "B8", "pages": "15611-15621" }, { "id": "authors:c5rx1-mp143", "collection": "authors", "collection_id": "c5rx1-mp143", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140304-105656882", "type": "article", "title": "CO_2-rich glass, round calcite crystals, and no liquid immiscibility in the system CaO-SiO_2-CO_2, at 2.5 GPa", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-W-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" } ], "abstract": "Following reports that the miscibility gap between silicate and carbonate liquids located experimentally on feldspar-calcite joins extended to the alkali-free side of the system CaONa_2O-Al_2O_3-SiO_2-CO_2, the melting of a mixture of calcite (70 wt%) and quartz was investigated\nat 2.5 GPa. The isobaric reaction, calcite (CC) + quartz (Qz) = liquid (L) + vapor (V), was reversed at 1350 \u00baC. Quartz and rounded calcite crystals were concentrated\nat the bottom of the capsule, and CO_2, was distributed in large vapor bubbles in the glass layer and at the top of the capsule. The liquid quenched to transparent glass, which is unusual in carbonate-rich systems. In two-stage reversal experiments, a sample of L + V that was heated to the subsolidus temperature of 1300, \u00baC produced a few rounded calcite grains organized in dendritic patterns; at 1200 \u00baC, dendritic intergrowths of CC + Qz were produced with some coarser-grained areas. The glass was found to contain about 20 wt% CO_2, on the basis of the geometry of phase boundaries and EDS analysis. There was no evidence for immiscible liquids. The round calcite crystals are equilibrium mineral phases, not quenched CaCO_3. liquids, and surface tension effects control their shapes. Infrared\nspectroscopic studies indicated that (CO_3)^(2-), is the dominant CO_2, species in the glass, and the silicate structure is partially polymerized, probably as a result of interaction between Ca^(2+) and SiO_4 tetrahedra. The phase relationships in the CaCO_3-SiO_2, system, the simplest\nmodel for subducted oceanic crust with limestone (or for basalt altered by sea water), show that subducted crust potentially could transport calcite to great depths for long-term storage in the mantle and could also yield low-SiO_2, carbonate-rich magmas under some thermal\nconditions. Such carbonate-rich melts may be efficient agents for mantle metasomatism.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1994-11", "series_number": "11-12", "volume": "79", "issue": "11-12", "pages": "1135-1144" }, { "id": "authors:t0bk2-ze727", "collection": "authors", "collection_id": "t0bk2-ze727", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150609-145505483", "type": "article", "title": "Subduction zone melting of pelagic sediments constrained\n by melting experiments", "author": [ { "family_name": "Nichols", "given_name": "Geoff T.", "clpid": "Nichols-G-T" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Stern", "given_name": "Charles R.", "clpid": "Stern-C-R" } ], "abstract": "The fate of pelagic sediments in subduction zones has an important bearing on global geochemical cycles and the thermal structure of subduction zones. Recent mass-balance calculations have indicated that about 20% of subducted sediments are recycled to volcanic arcs. Trace-element studies of these volcanic arcs imply that the subducted sediment melts while the gabbroic crust that underlies it dehydrates. This requires a rather specific thermal structure in subduction zones. Here we report laboratory melting experiments that allow us to derive melting curves for pelagic red clay at pressures of up to 40 kbar, equivalent to depths of 120 km within the mantle. The melting behaviour of wet red clay is similar to that for wet gabbro, but melting occurs at a slightly lower temperature, showing that sediment melting and gabbro dehydration can occur at the same temperature. The combination of trace-element data and phase diagrams such as that derived here may thus be used to constrain the temperature of the slab\u2013mantle boundary.", "doi": "10.1038/371785a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1994-10-27", "series_number": "6500", "volume": "371", "issue": "6500", "pages": "785-788" }, { "id": "authors:dyp8k-4a552", "collection": "authors", "collection_id": "dyp8k-4a552", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-110711851", "type": "article", "title": "Sulfur Variations in Glasses from Volcanic Rocks: Effect of Melt Composition on Sulfur Solubility", "author": [ { "family_name": "Ducea", "given_name": "Mihai N.", "orcid": "0000-0002-5322-0782", "clpid": "Ducea-M-N" }, { "family_name": "McInnes", "given_name": "Brent I. A.", "clpid": "McInnes-B-I-A" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "A worldwide data set of major element and sulfur analyses of undegassed lavas, pumices, and melt inclusions from 14 volcanic locations was selected to investigate the compositional effects on sulfur solubility in magmas. We utilized analyses on calc-alkaline, alkaline, and tholeiitic rocks, with a range of 3400 ppm S variation. There is a strong correlation between chemical composition and the sulfur concentration: the less silicic and the more alkaline the rocks are, the more dissolved sulfur they can carry. Also, sulfur concentration is higher in rocks that represent less polymerized melts. Elemental correlations between FeO and S, well-defined for tholeiites, do not hold for alkaline melts. The compositional effects are at least as important as the better-known pressure, temperature, and f(O_2) dependencies.", "doi": "10.1080/00206819409465483", "issn": "0020-6814", "publisher": "V.H. Winston & Son", "publication": "International Geology Review", "publication_date": "1994-08", "series_number": "8", "volume": "36", "issue": "8", "pages": "703-714" }, { "id": "authors:b4y0s-jh830", "collection": "authors", "collection_id": "b4y0s-jh830", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160111-154022819", "type": "article", "title": "Comparison of element and isotope diffusion of K and Ca in multicomponent silicate melts", "author": [ { "family_name": "van der Laan", "given_name": "Sieger", "clpid": "van-der-Laan-S-R" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Kennedy", "given_name": "Allen K.", "clpid": "Kennedy-Allen-K" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Recent experimental work has shown that the homogenization of elemental concentrations can be much slower than that of isotopic ratios when there are strong concentration gradients in SiO_2 and Al_2O_3. The ramifications of this result for magma homogenization and other petrological problems related to diffusion are significant. We report here a comparison of experimental profiles of elemental concentrations and isotopic fractions of K and Ca in rhyolite-andesite (large concentration gradients) and rhyolite-rhyolite (small concentration gradients) melt couples.\nWhen the concentration profile and the isotopic profile of the same element in a single couple are compared, the former is much shorter than the latter in the rhyolite-andesite couple, consistent with other recent studies. However, the lengths of both concentration and isotopic profiles are similar in the rhyolite-rhyolite couple. Therefore, diffusion of an element or oxide may be decoupled from or coupled with isotopic 'diffusion', depending on whether large concentration gradients of major components are present.\nWhen the two couples are compared, the intrinsic effective binary diffusivities obtained from isotopic profiles are similar for each element in the two couples, whereas the effective binary diffusivity of K obtained from the concentration profile in the rhyolite-rhyolite couple is 37 times that in the rhyolite-andesite couple. Therefore, isotopic homogenization is roughly independent of elemental homogenization and the presence of SiO_2, Al_2O_3, and other concentration gradients, whereas elemental homogenization is strongly affected by concentration gradients.\nOur experimental data (isotopic and concentration profiles including uphill diffusion profiles) can be modeled quantitatively to a good approximation using a modified effective binary diffusion model in which the flux of a component is assumed to be proportional to its activity gradient instead of its concentration gradient. Therefore, the multicomponent diffusion effect in the silicate systems of our experiments seems to be largely due to contributions of non-ideal mixing to the cross-terms of the diffusivity matrix.", "doi": "10.1016/0012-821X(94)90264-X", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1994-05", "series_number": "1-3", "volume": "123", "issue": "1-3", "pages": "155-166" }, { "id": "authors:vsbs5-1v690", "collection": "authors", "collection_id": "vsbs5-1v690", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-101913884", "type": "article", "title": "Rock System Science in Earth System Science", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Burke", "given_name": "Kevin C.", "clpid": "Burke-K-C" }, { "family_name": "Price", "given_name": "Jonathan G.", "clpid": "Price-J-G" } ], "abstract": "Changes in science, education, and policy,\ninvolving the earth sciences, demand the\nattention of our community:\nCongress will redirect so-called curiosity-driven\nresearch support toward research with\nsocietal relevance.\nCareer opportunities are shifting from\ndominance by the mineral and fuel industries to\ndominance by industries concerned with hydrology,\nland use, environmental and urban\ngeology, and waste isolation.\nEarth system science is being embraced in\nresearch and education as a multidisciplinary,\nintegrating theme that can enhance understanding\nof local geosystems.", "issn": "0016-8556", "publisher": "American Geological Institute", "publication": "Geotimes", "publication_date": "1994-04", "series_number": "4", "volume": "39", "issue": "4", "pages": "4" }, { "id": "authors:j9dhh-24c38", "collection": "authors", "collection_id": "j9dhh-24c38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-100001733", "type": "article", "title": "Dehydration-melting of amphibolite at 10 kbar: the effects of temperature and time", "author": [ { "family_name": "Wolf", "given_name": "Michael B.", "clpid": "Wolf-M-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We have simulated the dehydration-melting of a natural, low-K, calcic amphibolite (67.4% hornblende, 32.5% anorthite) in piston-cylinder experiments at 10 kbar and 750\u20131000\u00b0C, for 1\u20139 days. The solidus temperature is lower than 750\u00b0C; garnet appears at 850\u00b0C. The overall reaction is: Hb + P \u2192 L + Cpx + Al-Hb + Ca \u2013 Hb + Ga + Opx. Three stages of reaction are: (1) melting dominated by the growth of clinopyroxene and garnet, with little change in composition of liquid or garnet, (2) a reversal of this reaction between 875\u00b0C and 900\u00b0C, with decreases in the amounts of liquid and garnet, and (3) a large increase in liquid along with the loss of hornblende and decrease of plagioclase while clinopyroxene and garnet increase. Garnet is enriched in pyrope and zoned from Fe-cores to Mg-edges (range \u223c3 mol % pyrope); liquid composition is enriched first in An (to \u223c950\u00b0C) and then in Ab. The liquids are more calcic and aluminous than natural tonalites, which is attributed to the plagioclase composition (An90). The formation of peraluminous liquid from the metaluminous amphibolite is caused by anorthite \u2014 not H2O-saturated conditions. The results are consistent with an amphibolite phase diagram with relatively high solidus temperatures in the garnet-absent field (900\u20131000\u00b0C), but with a solidus backbend at \u223c7\u20139 kbar, coincident with the garnet-in boundary. Hornblende breakdown due to garnet formation in a closed system must make H_2O available for H_2O-undersaturated melting right down to the H_2O-saturated solidus, below 700\u00b0C, which defines a large low-temperature PT area where hydrous granitoid melts can be generated with residual garnet and hornblende.", "doi": "10.1007/BF00320972", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1994-02", "series_number": "4", "volume": "115", "issue": "4", "pages": "369-383" }, { "id": "authors:wb8sn-6mt23", "collection": "authors", "collection_id": "wb8sn-6mt23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160310-155530266", "type": "article", "title": "Experimental Data Bearing on Liquid Immiscibility, Crystal Fractionation, and the Origin of Calciocarbonatites and Natrocarbonatites", "author": [ { "family_name": "Lee", "given_name": "Woh-Jer", "clpid": "Lee-Woh-Jer" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Controversies about the role of carbonate-rich melts in processes ranging from mantle metasomatism to carbonatite eruptions involve debates about the following issues. (1) Are carbonatite magmas primarily from the mantle, or differentiates from silicate parents in the crust? (2) Are parental carbonatite magmas calcic, dolomitic, or sodic? (3) Are carbonatite magmas derived in the crust by liquid immiscibility or crystal fractionation? Experimental data provide the following constraints: primary carbonatite magmas formed in mantle lherzolite at depths greater than \u223c70 km are dolomitic; melts richer in calcite can be formed only in wehrlites at shallower depths; immiscible carbonatite magmas formed in the crust have variable Ca/Na, with no more than 80% dissolved CaCO_3, and commonly less; dolomitic melts from fertile peridotite, and more calcic melts from immiscibility, can fractionate to yield sodic melts.\n\nA test experiment confirms previous results in the join NaAlSiO_4-NaAlSi_3O_8-CaCO_3(Ne-Ab-CC)-H_2O (at 0.1 GPa and below 960\u00b0 C), illustrating that fractional crystallization of nepheline-normative silicate-CO_2 liquid can yield a residual carbonatitic liquid, precipitating calcite and becoming enriched in Na_2CO_3; the fractionation path passes below the silicate-carbonate liquid miscibility gap that exists at higher temperatures. The experiment with 10% H_2O (near Ne_(35)CC_(65) by weight) at 833\u00b0 C identifies the crystallization reaction: 1 liquid + 0.2 melilite(sodic) + 0.2 CO_2 = 0.5 cancrinite + 0.6 calcite + 0.1 H_2O. The liquid quenches to a fine-grained assemblage, including laths of nyerereite, equant grains of cancrinite, and calcite, mostly precipitated in quench overgrowth rims enclosing cancrinite that border the round, primary calcite crystals. The liquid composition was determined from scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) analyses over areas up to 2,500 \u03bcm^2, modal counts, and mass balance calculations; the maximum H_2O content was assigned using published solubility data, yielding a liquid composition: 26% CaO, 10% Na_2O, 14% Al_2O_3, 15% SiO_2, 23% CO_2, and 11% H_2O, equivalent to 36% nepheline, 43% calcite, and 9% nyerereite with H_2O and about 1% Al_2O_3, slightly enriched in Na_2CO_3 compared with the starting material. Deductions from available experimental studies indicate that fractional crystallization of a hydrous CO_2-bearing nepheline-normative magma at moderate temperatures may produce continuous liquid compositions from silicate to carbonate rich, precipitating a series of mineral assemblages analogous to rocks at the Oka Complex. Alkali-enriched carbonatite melts capable of precipitating cumulate sovites can be generated in several ways at crustal depths, but there is as yet no experimental evidence for petrological processes capable of forming nearly pure CaCO_3 liquids at feasible temperatures and pressures. Previous claims for such liquids through immiscibility are now revised. The proposed existence of calciocarbonate parental magmas requires substantiation by a viable process.", "doi": "10.1080/00206819409465489", "issn": "0020-6814", "publisher": "V.H. Winston & Son", "publication": "International Geology Review", "publication_date": "1994", "series_number": "9", "volume": "36", "issue": "9", "pages": "797-819" }, { "id": "authors:zkdt5-x9c21", "collection": "authors", "collection_id": "zkdt5-x9c21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160310-101949227", "type": "article", "title": "Earth sciences and society: a global overview", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "This paper elucidates the close relationship between the earth sciences and society, and also between the basic and applied aspects of the former. The author concludes that human activities are not only affected by, but they have significant effects on the environment. Human society is part of earthly cycles, obtains resources from them, and now causes significant perturbations of them. We need global understanding to ensure that society's aggressive attack does not disrupt the protective wrapping of fluid envelopes and soil. Such research is a good investment for society.", "issn": "1005-2321", "publisher": "Zhongguo di zhi da xue", "publication": "Earth Science Frontiers", "publication_date": "1994", "volume": "1", "pages": "7-12" }, { "id": "authors:4f2p3-af119", "collection": "authors", "collection_id": "4f2p3-af119", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-090231712", "type": "article", "title": "Relationships between silicate melts and carbonate-precipitating melts in CaO-MgO-SiO_2-CO_2-H_2O at 2 kbar", "author": [ { "family_name": "Otto", "given_name": "J. W.", "clpid": "Otto-J-W" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase fields intersected by three joins in the System CaO-MgO-SiO_2-CO_2-H_2O at 2 kbar were investigated experimentally to determine the melting relationships and the sequences of crystallization of liquids co-precipitating silicate minerals and carbonates. These joins connect SiO_2 to three mixtures of CaCO_3-MgCO_3-Mg(OH)_2 with compositions on the primary field for calcite, between the composition CaCO_3 and the low-temperature (650\u00b0C eutectic liquid co-precipitating calcite, dolomite and periclase. In the pseudo-quaternary tetrahedron calcite-magnesite-brucite-diopside, two of the significant reactions found are: (1) a eutectic at 650\u00b0C, calcite + dolomite + periclase + forsterite + vapor = liquid, and (2) a peritectic at 1038\u00b0C which is either calcite + \u00e5kermanite + forsterite + vapor = monticellite + liquid calcite + monticellite + forsterite + vapor = \u00e5kermanite + liquid. The eutectic liquid has high MgO/CaO and CO_2/H_2O and only 2\u20133% SiO_2 (estimated 15\u201320% MgCO_3, 35\u201340% CaCO_3, 40\u201345% Mg(OH)_2, and 5\u20136% Mg_2SiO_4). The composition joins intersect a thermal maximum for \u00e5kermanite + forsterite + vapor = liquid, which separates high-temperature liquids precipitating silicates together with a little calcite, from low-temperature liquids precipitating carbonates with a few percent of forsterite; there is no direct path between the silicate and synthetic carbonatite liquids on these joins, but it is possible that fractionating liquid paths diverging from the joins may connect them. More complex relationships involving the precipitation of monticellite and \u00e5kermanite are also outlined. Magnetite-magnesioferrite may replace periclase in natural magmatic systems. The results indicate that the assemblage calcite-dolomite-magnetite-forsterite represents the closing stages of crystallization of carbonatites, whereas assemblages such as calcite-magnetite-forsterite and dolomite-magnetite-forsterite span the whole range of carbonatite evolution in terms of temperature and composition, and provide the link between liquids precipitating silicates and those precipitating carbonates.", "doi": "10.1007/BF01163107", "issn": "0930-0708", "publisher": "Springer", "publication": "Mineralogy and Petrology", "publication_date": "1993-06", "series_number": "2-4", "volume": "48", "issue": "2-4", "pages": "343-365" }, { "id": "authors:tbcpj-drb49", "collection": "authors", "collection_id": "tbcpj-drb49", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-084841784", "type": "article", "title": "Experimental Interaction of Granitic and Basaltic Magmas and Implications for Mafic Enclaves", "author": [ { "family_name": "van der Laan", "given_name": "Sieger R.", "clpid": "van-der-Laan-S-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We have performed time series experiments for periods ranging from 3 min to 44 h on the interaction of granite melt and partially molten basalt at 920\u00b0C and 10 kbar, in the presence of 5 wt.% water. With time, the assemblage of the basalt domain changes from predominantly amphibole+plagioclase to clinopyroxene+garnet; the melt fraction increases from \u02dc2\u22c55 to 40%; and between the two domains, the melt compositions progressively equilibrate. Initially in each run, melts of the basalt domain have uniform plateau concentrations for SiO_2, Al_2O_3, CaO, MgO, and FeO because the activities of these components are regulated by the mineral assemblage, but at advanced stages of reaction, no such control is evident. We have derived analytical expressions to describe and simulate the diffusion profiles. The concentration profiles for SiO_2, Al_2O_3, CaO, and Na_2O in the granite, emanating from the basalt\u2013granite interface, have been used to estimate effective diffusivities. The values from the shorter runs are compared with those of the experiment of longest duration for which we assumed finite couples in our calculations. In the diffusion calculations for K2O the difference in melt fraction between the two domains is accounted for. The resulting values (in cm^2/s) are: D_(Na_2O)=6 \u00d7 10^(\u20137), D_(K_2O)=3 \u00d7 10^(\u20137), D_(MgO)=9 \u00d7 10^(\u20138), D_(CaO)=(4\u20136) \u00d7 10^(\u20138), and D_(SiO_2) and D_(Al_2O_3)=(3\u20130\u22c56) \u00d7 10^(\u20138). They are in reasonable agreement with values from other studies. On the basis of our experiments we calculate that mafic enclaves of magmatic origin should equilibrate to a large degree with their host magma in slowly cooling non-convecting granitic plutons. Enclaves approaching complete re-equilibration retain distinctly higher modal amounts of mafic minerals. They do not compositionally resemble binary magma mixtures, but are more like host magma with accumulated crystals. We show that the modal differences between enclave and host are indicative of the temperature of homogenization and that, in principle, this temperature can be deduced from equilibrium phase diagrams.", "doi": "10.1093/petrology/34.3.491", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1993-06", "series_number": "3", "volume": "34", "issue": "3", "pages": "491-517" }, { "id": "authors:k45q1-gdn73", "collection": "authors", "collection_id": "k45q1-gdn73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160310-100941585", "type": "article", "title": "Garnet Growth during Amphibolite Anatexis: Implications of a Garnetiferous Restite", "author": [ { "family_name": "Wolf", "given_name": "Michael B.", "clpid": "Wolf-M-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Formation of a garnet clinopyroxenite restite may have important physicochemical consequences for deep crustal and mantle processes. We have experimentally simulated the dehydration-melting of amphibolite, and report the modal and compositional evoltuion of the mafic granulitic mineral assemblage (the restite), with an emphasis on garnet. A natural, low-K, calcic amphibolite was powdered and run in sealed, gold capsules in a piston-cylinder apparatus at 10 kbar, 750-1000\u00b0C, 1 to 9-day runs, and fO_2~ Ni-NiO. Garnet first appears in 8-day runs at 825\u00b125\u00b0C. Above 850\u00b0C, clinopyroxene and poikilitic garnet comprise most of the restite. Garnet peaks at 950\u00b0C (at ~32 vol.% of the material within the capsule, or 41 vol.% of the restite assemblage) and disappears between 975-1000\u00b0C. There is no cross-over of Fe-Mg partitioning between coexisting liquids and garnets. Liquids remain Mg-poorer than garnets throughout the melting interval but do increase in Mg# with increasing temperature; thus the hotter liquids may be less likely to react with mantle wedge peridotite. The modes are consistent with REE patterns of Archean tonalitic-trondhjemitic rocks generated by the partial melting of garnet-bearing mafic crust. A garnet clinopyroxenite with 41 vol.% garnet has a density of 3.5g/cm^3, which may induce lower crustal delamination in hot, nonthickened, amphibolitic crust. This crust is seismically indistinguishable from lithosphere or mantle. Because garnet growth traps water-bearing hornblende inclusions, the restite may contain up to 0.3 wt.% water. Thus, delivery of poikilitic garnet to the mantle, possibly by delamination or by subduction, may be an important mechanism for adding water to the mantle.", "doi": "10.1086/648229", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1993-05", "series_number": "3", "volume": "101", "issue": "3", "pages": "357-373" }, { "id": "authors:wk4pw-yrs26", "collection": "authors", "collection_id": "wk4pw-yrs26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-103854855", "type": "article", "title": "Some products of experimental dehydration-melting of amphibolite at 10 kbar", "author": [ { "family_name": "Wolf", "given_name": "M. B.", "clpid": "Wolf-M-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The dehydration-melting of a natural, low-K, calcic amphibole in a piston-cylinder apparatus\nat 10 kbar and 750-1000 \u00b0C, for 1-9 days, has revealed a solidus temperature of less than\n750 \u00b0C - lower than values reported from other amphibole experiments. Amphibolites begin\nto melt at relatively high temperatures in the garnet-absent field, with the formation of\naugite. But in our experiments the formation of garnet from fully hydrated [hornblende +\nplagioclase] involves the release of H_2O which is transferred directly into H_2O-undersaturated\nliquid (without the intervention of a vapor phase); the solidus near 10 kbar thus bends\nback to follow the garnet-in phase boundary, with low positive dP/dT, and it extends down\nto the H_2O-saturated solidus. The lower solidus temperature provides an expanded field for\nliquid + garnet + hornblende, allowing for the formation of HREE-depleted liquidus during\namphibolite anatexis over a wider range of P-T conditions than indicated by 9ther\nexperiments. The liquidus are more calcic and aluminous than natural continental tonalites\nand oceanic plagiogranites, due to the high anorthite content of the plagioclase (Au_(90)). The\nexperimental liquidus contain 2-8 wt. % H_2O (mass balance) and those between 875 \u00b0C and\n900 \u00b0C have low calculated viscosities (~ 10 Pa\u00b7s). Liquid interconnectivity has been\ndemonstrated in corollary work on solid amphibole, so it is possible that these HREE-depleted liquidus could begin to segregate from the amphibolite source (reaching to a granulitic\nrestite assemblage or clinopyroxene, garnet, plagioclase, and orthopyroxene) at relatively low\ntemperatures ( < 900 \u00b0C) and very low liquid fractions ( < 5 vol.%). The abundant formation\nof garnet can form dense garnet clinopyroxene restite that has implications such as\ndelamination or deep mafic crust.", "issn": "1068-7971", "publisher": "Allerton Press", "publication": "Russian Geology and Geophysics", "publication_date": "1993", "series_number": "12", "volume": "34", "issue": "12", "pages": "90-102" }, { "id": "authors:v07vj-nxk27", "collection": "authors", "collection_id": "v07vj-nxk27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-144155620", "type": "article", "title": "High-pressure apatite solubility in carbonate-rich liquids: Implications for mantle metasomatism", "author": [ { "family_name": "Baker", "given_name": "Michael B.", "clpid": "Baker-M-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "At pressures higher than \u223c22 kbar, near-solidus melts of peridotite + CO_2 + H_2O are carbonatitic and may be able to separate from their source regions at liquid fractions as low as 0.01%. At such low degrees of partial melting, trace-element-rich accessory phases may remain in the residue and have a dramatic effect on abundances and ratios of incompatible elements. We have determined the solubility of apatite in carbonate-rich melts at 30 kbar and over a temperature range of 1120\u20131430\u00b0C. The P_2O_5 content of an apatite-saturated liquid is given by the expression In (P_2O_5 wt%) = 4.834 \u2212 3,809/7+ \u2211 d_iC_i, where T is the absolute temperature in Kelvin and the di represent the constants 0.0113 and \u22120.00574, which modify wt% concentrations of CaO and CO_2 in the liquid. The quenched liquids have silica contents between \u223c1.5 and 10 wt% and are also characterized by low solubilities of garnet, rutile, and ilmenite. Our experiments yield a partition coefficient for P between clinopyroxene and carbonate melt of 0.0067 \u00b1 0.0016. Based on mineral/clinopyroxene P ratios from the literature, high-pressure olivine, orthopyroxene- and garnet-carbonatitic liquid partition coefficients for P are therefore approximately 0.003, 0.001, and 0.01, respectively. For mantle P_2O_5 contents between 0.03 and 0.05 wt%, <1 wt% apatite coexists with low-degree melts, and apatite is rapidly consumed near the solidus. At concentrations < 0.02 wt%, P probably resides completely in the silicate phases. Nodule data suggest that relatively large volumes of the mantle have P contents \u2264 0.05 wt%. Because near-solidus carbonatitic liquids probably represent very low degrees of partial melting, even minor amounts of residual apatite can substantially affect LREE contents in the melt. Our experimental data also indicate that near-solidus carbonatitic melts can have P_2O_5-TiO_2 ratios much higher than those observed in primitive nephelinitic lavas or kimberlites. Data on cryptically metasomatized spinel harzburgites suggest that the metasomatizing agents also had high P-Ti ratios.", "doi": "10.1016/0016-7037(92)90388-Y", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1992-09", "series_number": "9", "volume": "56", "issue": "9", "pages": "3409-3422" }, { "id": "authors:kf8vz-4yb19", "collection": "authors", "collection_id": "kf8vz-4yb19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-145507525", "type": "article", "title": "Solidus reactions in synthetic lherzolite-H_2O-CO_2 from 20\u201330 kbar, with applications to melting and metasomatism", "author": [ { "family_name": "White", "given_name": "Bradford S.", "clpid": "White-B-S" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mixtures of synthetic forsterite, enstatite, diopside and natural dolomite were used to determine solidus reactions for synthetic lherzolite-H_2O (passing through 1125, 1060 and 1005\u00b0C, at 10, 20 and 30 kbar, respectively), and dolomite-lherzolite with mixed vapor, two curves not previously located experimentally. The vapor-buffered curve for dolomite-lherzolite has a distinctive pressure minimum, passing down from the CO_2 system near 28 kbar and 1230\u00b0C to a minimum near 22 kbar and 1975\u00b0C, with decreasing CO_2/H_2O in the vapor, and then up in pressure through a point at 30 kbar and 990\u00b0C. These new results, together with published results in other parts of the system, permit complete construction of the three divariant solidus and decarbonation surfaces meeting along the vapor-buffered dolomite-lherzolite solidus curve. The vapor phase composition at the pressure minimum on this curve is about 85 mol% CO_2. The corresponding curve for natural peridotites is complicated by the addition of amphibole. The three surfaces define boundaries between regions where various kinds of metasomatic fluids can exist. Their positions are moved to somewhat lower temperatures for natural peridotites, and the significant vapor-buffered solidus ledge occurs within a narrow pressure interval at about 75 km depth. Rapid changes in melt and vapor phase compositions coexisting with peridotite occur within this interval. Shallower than about 75 km, silicate and not carbonatite magmas coexist with peridotite; vapors may range from CO_2 to H_2O. Deeper than about 75 km, near-solidus melts are carbonatitic, with vapor if present being H_2O-rich; CO_2-rich vapors cannot exist. Rising volatile-rich melts (of moderate temperatures) in equilibrium with peridotite must begin to crystallize and give off vapors near this depth, with compositions changing from H_2O- to CO_2-rich as depth decreases. Melts and vapors separate rapidly from crystals at this and greater depths.", "doi": "10.1016/0377-0273(92)90040-K", "issn": "0377-0273", "publisher": "Elsevier", "publication": "Journal of Volcanology and Geothermal Research", "publication_date": "1992-04-15", "series_number": "1-2", "volume": "50", "issue": "1-2", "pages": "117-130" }, { "id": "authors:sx4by-1yb12", "collection": "authors", "collection_id": "sx4by-1yb12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160310-074639821", "type": "article", "title": "Constraints on Archean Trondhjemite Genesis from Hydrous Crystallization Experiments on N\u00fbk Gneiss at 10-17 Kbar", "author": [ { "family_name": "van der Laan", "given_name": "Sieger R.", "clpid": "van-der-Laan-S-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We present crystallization experiments on Archean N\u00fbk gneiss from West Greenland, and relate these to conditions for early continental crustal genesis. The studied composition is a trondhjemite from a voluminous felsic intrusive phase dated at 2,800-3,000 m.y. In a detailed set of experiments at 10 kbar, the liquidus mineralogy is observed to change with increasing water content from plagioclase above 1000\u00b0C and <3.5 wt % water, to clinopyroxene at 850-1000\u00b0C with 3.5-7 wt % water, to hornblende below 850\u00b0C with >7 wt % water. Water saturation of the melt occurs with 10.5 wt % water at 800\u00b0C. Mafic liquidus minerals at 15 kbar differ from those at 10 kbar in that garnet replaces pyroxene, and that epidote replaces hornblende below 690\u00b0C at >13 wt % water and at water saturation (15.5 wt %). Garnet crystallization is never observed at pressures below 13 kbar. Using additional experiments at 12.5, 13, and 17 kbar, the liquidus phase variation for trondhjemite with water is accurately defined between 8-18 kbars and 700-1200\u00b0C. Based on its liquidus mineralogy, this trondhjemite melt with 7-8 wt % water coexists with garnet, hornblende, clinopyroxene, and plagioclase at approximately 900\u00b0C at 14 kbar. At lower water contents than 7 wt % and higher temperatures than 900\u00b0C, plagioclase \u00b1\ngarnet crystallization is expected at pressures above 13 kbar and plagioclase \u00b1\npyroxene crystallization is expected at pressures below 13 kbar. REE patterns of N\u00fbk gneiss prescribe a hornblende- or garnet-bearing residue from which the trondhjemite melts were extracted. For hornblende this requires high melt water contents (>8 wt %) and melting at temperatures below 900\u00b0C. For garnet, generally lower water contents and higher pressures and temperatures are needed. The experiments also indicate that trondhjemites are part of a narrow compositional interval in which water-bearing melts will form magmatic epidote at pressures of 8 kbar and higher. A near-solidus assemblage containing epidote + biotite + plagioclase (\u2248 20-30%An) + quartz should be expected in such rocks.", "doi": "10.1086/629571", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1992-01", "series_number": "1", "volume": "100", "issue": "1", "pages": "57-68" }, { "id": "authors:zxfz1-tnf02", "collection": "authors", "collection_id": "zxfz1-tnf02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-132943477", "type": "article", "title": "Partitioning of Cu, Sn, Mo, W, U, and Th between melt and aqueous fluid in the systems haplogranite-H_2O-HCl and haplogranite-H_2O-HF", "author": [ { "family_name": "Keppler", "given_name": "Hans", "clpid": "Keppler-H" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The partition coefficients K_D=c_(fluid)/c_(melt) of Cu, Sn, Mo, W, U, and Th between aqueous fluid and melt were measured in the systems haplogranite-H_2O\u2212HCl and haplogranite-H_2O\u2212HF at 2kbars, 750\u00b0C, and Ni\u2212NiO buffer conditions using rapid-quench cold seal bombs, with many reversed runs. Concentrations of trace elements (1\u20131000 ppm) in the quenched aqueous fluid and in the glass were determined by plasma emission spectrometry (DCP). KD of F is close to 1 in the system studied. K_D of Cu and Sn strongly increases with increasing Cl concentration due to the formation of chloride complexes in the aqueous fluid, while HF has no effect. However, in 2M HCl, K_D of Cu approaches 100, while K_D of Sn is below 0.1 under the same conditions. The partition coefficients of Mo and W are high if water is the only volatile present (Mo: 5.5, W: 3.5), but strongly decrease with increasing HCl and HF, due to the destabilization of hydroxy complexes. K_D of U and Th is very low in the absence of complexing agents, but strongly increases with increasing HF concentration. KD of U also increases with increasing HCl concentration and with increasing CO_2 concentration in the system haplogranite-H_2O\u2212CO_2, indicating the stability of chloride and carbonate complexes of U at magmatic temperatures. The data suggest a stoichiometric ratio of Cl: U=3:1 and of F:U=2:1 in these complexes. Cl-rich fluids are responsible for the formation of porphyry Cu deposits, but are much less effective in the transport of Sn. F appears not to be essential for the concentration of Mo and W in fluids evolving from a granitic magma. The different complexing behavior of U and Th in aqueous fluids may account for their fractionation during magma genesis.", "doi": "10.1007/BF00306474", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1991-12", "series_number": "2", "volume": "109", "issue": "2", "pages": "139-150" }, { "id": "authors:03rdh-pw973", "collection": "authors", "collection_id": "03rdh-pw973", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-132100249", "type": "article", "title": "Dehydration-melting of solid amphibolite at 10 kbar: Textural development, liquid interconnectivity and applications to the segregation of magmas", "author": [ { "family_name": "Wolf", "given_name": "M. B.", "clpid": "Wolf-M-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Anisotropic crystal structures and rock texture control liquid morphology and distribution during dehydration-melting at 10 kbar in solid cylinders of lineated amphibolite (mode: hornblende 70%, plagioclase 30%), sealed in gold capsules, in piston-cylinder runs ranging from 21 days at 850 \u00b0C to 4 days at 1000 \u00b0C. The shapes of most liquid pockets are crystallographically-controlled, with many corners having angles greater than 60\u00b0. Few crystal/liquid triple junctions develop the interfacial energy-controlled dihedral angles (\u03b8), which form in experiments using finely-ground powders of minerals with poor cleavage. Liquid interconnectivity probably is attained at 875 \u00b0C with only 2% liquid, indicating that dihedral angles less than 60\u00b0 may not be necessary to achieve interconnectivity in partially melted metamorphic rocks. The surfaces between elongated grains in lineated rocks can become pathways for the migration of liquid or the diffusion of components. By 850 \u00b0C, hornblende begins to dehydrate at internal nucleation sites, producing a texture of hornblende rims and clinopyroxene cores (generally attributed to hydration of clinopyroxene). Within the temperature interval of 850\u2013900 \u00b0C, transient vapor generates layers of low viscosity, H_2O-saturated, granitoid liquid between hornblende and plagiocase crystal faces, potentially capable of segregation if time-temperature relationships are suitable. At higher temperatures the increased liquid fraction is H2O-undersaturated, with viscosity too high to permit segregation. There is a prospect that segregation of initially hydrous liquids could contribute to the dehydration of low-potassium amphibolites and effectively remove incompatible trace elements during the transition from amphibolite-facies to granulite-facies. Further experiments are needed to study the effects of time and temperature on textures in anisotropic rocks, particularly lineated amphibolites.", "doi": "10.1007/BF01166961", "issn": "0930-0708", "publisher": "Springer", "publication": "Mineralogy and Petrology", "publication_date": "1991-09", "series_number": "3-4", "volume": "44", "issue": "3-4", "pages": "151-179" }, { "id": "authors:ered6-17g95", "collection": "authors", "collection_id": "ered6-17g95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-131520576", "type": "article", "title": "Opening Ceremony: Address by the President. 15th General Meeting, International Mineralogical Association, Beijing, China (1990)", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "His excellency Premier Li Peng, distinguished guests, fellow\nmineralogists, ladies and gentlemen:\nIt is my pleasant responsibility as President of IMA\nto welcome participants to this 15th General Meeting,\nand to thank our Chinese hosts for the years of hard\nwork that they have put into preparation for the Meeting.\nSpecial thanks are due to Xie Xiande, Huang Yunhui, and Wang Zejiu, and to other members of the Scientific\nand Organizing Committees.\nFor some of you, this is a first General Meeting of\nIMA. Others are old hands who can recount events at\nMeetings 30 or 40 years ago. Unfortunately, we lack the\nparticipation of some individuals and National Mineralogical\nSocieties because they chose to stay away on account\nof the events that took place a year ago. We are\nhere because we believe in the continued need for international communication in science - in mineralogy, and\nbecause we chose to support our Chinese mineralogical\ncolleagues. I am confident that the exchange of ideas\nduring the next few days will be to the benefit of all,\nand I am sure that new projects and collaborations will\ndevelop as a result of activities at this Conference.", "doi": "10.1007/BF00310712", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1991-04", "series_number": "2", "volume": "107", "issue": "2", "pages": "264-265" }, { "id": "authors:32q4w-8hn41", "collection": "authors", "collection_id": "32q4w-8hn41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160309-082544124", "type": "article", "title": "Melting experiment of biotite gneiss-H_2O system at 0.1-0.2 GPa pressures", "author": [ { "family_name": "Wu", "given_name": "Zongu", "clpid": "Wu-Zongu" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "[no abstract]", "issn": "1000-6524", "publisher": "Di zhi chu ban she", "publication": "Acta petrologica et mineralogica", "publication_date": "1991", "volume": "10", "pages": "102-113" }, { "id": "authors:br544-6f309", "collection": "authors", "collection_id": "br544-6f309", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141205-102337602", "type": "article", "title": "AGU Planet Earth Committee Report: Part II: Interior and Crust", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Kaula", "given_name": "William M.", "clpid": "Kaula-W-M" } ], "abstract": "The Earth's mantle, core, and crust comprise 99.98% of its mass. The mantle, making up the bulk of the mass at 70% and composed of higher density rocks (rich in magnesium silicates, plus some iron silicates), extends an average of 15\u20132900 km deep. The core is the center of the Earth, 2900\u20136370 km deep, composed mainly of molten iron. The crust is the outermost layer of the solid Earth, composed of lower density rocks (rich in silica and aluminum and calcium silicates) 6\u201340 km thick.", "doi": "10.1029/90EO00374", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1990-12-18", "series_number": "51", "volume": "71", "issue": "51", "pages": "1870" }, { "id": "authors:tme6y-e0p81", "collection": "authors", "collection_id": "tme6y-e0p81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150408-103739303", "type": "article", "title": "Role of fluids in transport and fractionation of uranium and thorium in magmatic processes", "author": [ { "family_name": "Keppler", "given_name": "Hans", "clpid": "Keppler-H" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The geochemistry of uranium and thorium is of considerable importance for understanding the Earth's heat budget, for U\u2013Th\u2013Pb age determinations, for the origin of ore deposits, and because disequilibria between the radioactive daughters of ^(238)U and ^(232)Th provide constraints on processes occurring during the generation of magmas. We have studied experimentally the partitioning of uranium and thorium between a haplogranitic melt and aqueous fluids containing variable amounts of HCl, HF and CO_2, at 2 kbar, 750 \u00b0C and the oxygen fugacity of the Ni\u2013NiO buffer. The partition coefficients K^(fluid/melt)_D are very low for both uranium and thorium if water is the only volatile component present, but they increase strongly with increasing fluoride concentration, indicating the formation of fluoride complexes in the fluid. Chloride and CO_2, on the other hand, form complexes with uranium, but not with thorium. These results explain the origin of hydrothermal uranium and thorium deposits, the fractionation of uranium from thorium during magma formation, and the depletion of uranium relative to thorium in granulite-facies rocks.", "doi": "10.1038/348531a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1990-12-06", "series_number": "6301", "volume": "348", "issue": "6301", "pages": "531-533" }, { "id": "authors:12w6s-xk738", "collection": "authors", "collection_id": "12w6s-xk738", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-080924074", "type": "article", "title": "Experimental boundaries for the origin and evolution of carbonatites", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Baker", "given_name": "Michael B.", "clpid": "Baker-M-B" }, { "family_name": "White", "given_name": "Bradford S.", "clpid": "White-B-S" } ], "abstract": "An integrated model is presented for the generation of crustal carbonatites in rift environments from mantle carbon, both primordial and recycled through subduction. The carbon is involved in the generation of melts in the asthenosphere and the melts are then processed in the lithosphere associated with continental rifting. Parental nephelinitic melts from about 75 km depth then yield the carbon in the form of carbonatite at shallower depths in the upper mantle, or within the crust. Selected experimental phase equilibrium data are reviewed to test parts of the model. Similar tests can be made for carbonatites formed in different tectonic environments. Experiments with lherzolite (synthetic and natural) confirm that with CO_2 and H_2O at depths greater than about 75 km, near-solidus liquids correspond to Ca-Mg carbonatites, enriched in alkalis; the prospect that primary carbonatites could be erupted from the mantle justifies a search for them, but volume relationships favor an origin by differentiation for most occurrences. A wide miscibility gap between silicate and carbonate liquids with variable Ca/Na and Ca/Mg extends from crust to mantle pressures, but primitive CO_2-bearing nephelinites do not yield immiscible carbonatite magmas at 75 km depth; immiscibility should occur commonly at shallower depths, certainly in the crust. Fractional crystallization of nepheline-normative magmas in the crust can yield the series of rocks occurring in some alkalic complexes with carbonatites. Carbonatite magmas differentiate: crystallization paths confirm the prospect of fractional crystallization of dolomite and calcite and the coprecipitation of calcite and bastnaesite from magmas.", "doi": "10.1016/0024-4937(90)90037-2", "issn": "0024-4937", "publisher": "Elsevier", "publication": "Lithos", "publication_date": "1990-12", "series_number": "1-2", "volume": "26", "issue": "1-2", "pages": "3-19" }, { "id": "authors:xt44r-tab53", "collection": "authors", "collection_id": "xt44r-tab53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150512-100226476", "type": "article", "title": "Liquid immiscibility in a nephelinite\u2013carbonate system at 25 kbar and implications for carbonatite origin", "author": [ { "family_name": "Baker", "given_name": "Michael B.", "clpid": "Baker-M-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mantle-derived carbonate-rich melts may have an important role in mantle metasomatism, and may serve as parent liquids for crustal carbonatite magmas. Experiments have shown that carbonatitic melts can be produced by partial melting of peridotite + CO_2 + H_2O above 22 kbar (ref. 3), and that silicate and carbonate liquids are immiscible between 2 and 15 kbar for a wide range of Ca/Na ratios. We have determined the extent of silicate-carbonate liquid immiscibility at 25 kbar and 1,050\u20131,300\u00b0C using mixtures of magnesian nephelinite, dolomite and sodium carbonate with and without water. In contrast to the low-pressure data, the two-liquid field at 25 kbar is restricted to more sodium-rich compositions, far removed from natural mantle melts. Our experimental results suggest that neither partial melting of carbonated peridotite, nor extensive fractional crystallization of silicate magmas at depths corresponding to 25 kbar, are likely to generate carbonatitic magmas by liquid immiscibility.", "doi": "10.1038/346168a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1990-07-12", "series_number": "6280", "volume": "346", "issue": "6280", "pages": "168-170" }, { "id": "authors:dzcnq-aqn32", "collection": "authors", "collection_id": "dzcnq-aqn32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-105834043", "type": "article", "title": "The system tonalite-H_2O at 15 kbar and the genesis of calc-alkaline magmas", "author": [ { "family_name": "Carroll", "given_name": "Michael R.", "clpid": "Carroll-M-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental phase relations and well-characterized mineral and melt compositions\nhave been determined for a Sierra Nevada tonalite (andesite) with 2.5 to 10 wt% H_2O\nadded at 15 kbar and 850 to 1100 \u00b0C. All results are from experiments conducted in Au\ncapsules (minimal Fe loss to capsule) at oxygen fugacities measured to be near Ni-NiO.\nWith increasing water content, the liquidus mineral changes from clinopyroxene at <3\nwt% H20 to garnet, followed within 50 \u00b0C by clinopyroxene at 3 to 9 wt% H_2O, to hornblende\nat water contents greater than ~9 wt%. Microprobe analyses of glasses quenched\nfrom within the tonalite melting interval show an enrichment in Ca relative to (Mg + Fe),\nwhere Fe represents total Fe as Fe^(2+), with increasing SiO_2 instead of the typical calcalkaline\ntrend of approximately constant Ca/(Mg + Fe) from basalt through rhyolite. The\nresults document the importance of garnet and clinopyroxene in andesitic to dacitic compositions\nat deep-crustal to uppermost-mantle pressures, and they indicate that it is not\npossible to directly produce magmas of calc-alkaline composition at 15 kbar and the\ninvestigated range of water contents by either (1) partial melting of tonalitic to gabbroic\n(eclogitic) lower crust or (2) crystal fractionation from melts of andesitic to basaltic composition.\nMelting or fractionation at lower pressures or with lower water contents may\nproduce calc-alkaline liquids as plagioclase replaces garnet as the major Al-bearing phase.\nCale-alkaline rocks showing evidence of garnet-liquid equilibration in their REE patterns\nmust also have undergone lower-pressure fractionation in order to explain their major-element\ncompositions.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1990-03", "series_number": "3-4", "volume": "75", "issue": "3-4", "pages": "345-357" }, { "id": "authors:b1ms5-v8y17", "collection": "authors", "collection_id": "b1ms5-v8y17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-081457948", "type": "article", "title": "Experimental petrology: Quantitative boundaries for petrogenesis", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The paper is an overview of the current status on experimental petrology \u2014 its objectives and its major role in solving problems related to various earth processes. It describes how investigations related to solid-solid transitions, dehydration or decarbonation reactions, and melting studies have helped to formulate petrological models for the earth's internal structure. It also describes how measurements of physical properties of minerals, melts and vapour under extreme conditions have provided vital information of fluid dynamics of magmatic systems. The paper narrates the role of experimental petrology in calibrating geophysical processes with petrological consequences. Model P-T-X (SiO_2)-fluid systems are considered to emphasize the role of various gas species in shifting the solidus in a P-T space, in degrees of melting and composition of the melt. Synthetic models and study of whole rock systems are considered to discuss the zonation and metasomatic processes in the mantle of the earth. The paper is also concerned with mantle convection and the uprise of thermal plumes, particularly, in the oceanic environment. It discusses the petrological structures associated with the plume and shows how static petrological maps are modified by the dynamics of the plumes.", "doi": "10.1007/BF02871892", "issn": "0253-4126", "publisher": "Spinger India", "publication": "Journal of Earth System Science", "publication_date": "1990-03", "series_number": "1", "volume": "99", "issue": "1", "pages": "5-19" }, { "id": "authors:k55yc-qty70", "collection": "authors", "collection_id": "k55yc-qty70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-104006520", "type": "article", "title": "Experimental Phase Relations in the System Tonalite-Peridotite-H_2O at 15 kb; Implications for Assimilation and Differentiation Processes near the Crust-Mantle Boundary", "author": [ { "family_name": "Carroll", "given_name": "Michael R.", "clpid": "Carroll-M-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experiments at 15 kb in the tonalite-peridotite-H_2O system provide information on some of the phase equilibrium factors that may influence reaction and assimilation processes between quartznormative magmas and ultramafic rocks in the deep crust and upper mantle. Experiments were done with 5 or 10 wt.% H_2O added to powdered natural samples of tonalite, and mixtures of tonalite with 5 or 10 wt.% peridotite added (TP5 and TP10, respectively). The liquidus phase relations of these starting compositions were investigated between 850 and 1100\u00b0C at 15 kb, using gold capsules so that iron loss to the sample containers was not a problem and meaningful glass and mineral analyses could be obtained. Experiments on the tonalite alone show either liquidus garnet, for samples with 5% H_2O added, or liquidus hornblende, for samples with 10% H_2O. In contrast, orthopyroxene is the sole liquidus phase, irrespective of water content, in experiments using starting mixtures of 5 or 10 wt.% peridotite added to tonalite. Glass analyses of partially crystallized tonalite define a crystallization path diverging significantly from the calc-alkaline trend towards higher Ca/(Mg + Fe) in the CaO\u2212(MgO + FeO)\u2212\u00bcSiO_2 triangle. In contrast, glasses from partially crystallized mixtures of tonalite with 5 or 10 wt.% peridotite added define a liquid trend close to natural calc-alkaline compositions in terms of Ca/(Mg + Fe). Of more general significance, the proximity of a field of liquidus orthopyroxene on the high (Mg + Fe) side of compositions along the calc-alkaline trend serves to limit the Mgenrichment of such melts by interaction with ultramafic rocks. Unless heat is added to the system, reaction of tonalitic composition melts with ultramafic rocks will produce only slightly Mg-enriched melts: increasing degree of reaction simply results in further precipitation of orthopyroxene + garnet \u00b1 clinopyroxene once melt compositions reach the orthopyroxene field boundary.", "doi": "10.1093/petrology/30.6.1351", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1989-12", "series_number": "6", "volume": "30", "issue": "6", "pages": "1351-1382" }, { "id": "authors:ya2f2-4vr31", "collection": "authors", "collection_id": "ya2f2-4vr31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160301-103259326", "type": "article", "title": "Experimental study of interaction between hydrous granite melt and amphibolite", "author": [ { "family_name": "Rutter", "given_name": "Michael J.", "clpid": "Rutter-M-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We have investigated the reaction between crystalline amphibolite and hydrous granite melt in static experiments at 810 \u00b0C and 1.5 kbar. Boundary layer concentration gradients in quenched silicate glass for the major element oxides and the volatile components, water and carbon dioxide, were measured using electron probe analysis and Fourier Transform Infrared Spectroscopy, respectively. We found a measurable change in the concentration of all components adjacent to the amphibolite in experiments of 66 and 330 hours duration. After I hour there was no detectable change in the concentration of major element oxides in the granitic glass, but steep concentration profiles were determined for carbon dioxide and water. A bubble-free zone developed adjacent to the amphibolite in the 66 hour experiment, and this zone increased in width after 330 hours. Reaction is controlled by dissolution of amphibolite and by transport of dissolved material through the granite melt. The rate-controlling process is chemical diffusion in the melt phase. Results confirm that in the absence of convective heat transfer and/or mechanical disaggregation of mafic inclusions, assimilation of mafic rocks by granite melt is very slow, corresponding to on the order of 10 mm for SiO_2 in 1000 years.", "doi": "10.1017/S0016756800006932", "issn": "0016-7568", "publisher": "Cambridge University Press", "publication": "Geological Magazine", "publication_date": "1989-11", "series_number": "06", "volume": "126", "issue": "06", "pages": "633-646" }, { "id": "authors:2sdv0-z7j69", "collection": "authors", "collection_id": "2sdv0-z7j69", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160107-160050768", "type": "article", "title": "The system tonalite-peridotite-H_2O at 30 kbar, with applications to hybridization in subduction zone magmatism", "author": [ { "family_name": "Johnston", "given_name": "A. Dana", "clpid": "Johnston-A-D" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We present data on the phase relationships of mixtures between natural tonalite and peridotite compositions with excess H_2O at 30 kbar, and on the composition of the piercing point where the peridotite-tonalite mixing line intersects the L(Ga,Opx) reaction boundary. These data, in conjunction with earlier analogous data along peridotite-granite and basalt-granite mixing lines, permit construction of a pseudoternary liquidus projection that is relevant to interaction of peridotite with slab-derived magmas. Knowledge of the liquidus phase and temperature for a range of compositions within this projection enables us to map primary crystallization fields for quartz, garnet, orthopyroxene, clinopyroxene, and olivine, and to estimate the distribution of isotherms across the projection. Using this projection, we explore the consequences of peridotite assimilation by mafic to intermediate (basalt to dacite) hydrous slab-derived melts. Progressive assimilation under isothermal conditions results in garnet precipitation as the melt composition traverses the garnet liquidus surface and then garnet+orthopyroxene crystallization once the melt reaches the L(Ga,Opx) field boundary. The melt is constrained to remain on this field boundary and further assimilation of peridotite simply results in continued precipitation of garnet+orthopyroxene until the melt is consumed. The product is a hybrid solid assemblage consisting of Ga+ Opx. It is noteworthy that this process drives the melt composition in a direction nearly perpendicular to the mixing line between peridotite and the initial melt. If assimilation occurs with increasing temperature (as might occur if a slab-derived magma rises into the hotter mantle wedge), intermediate magmas (e.g. andesites) will again precipitate garnet until they reach the L(Ga,Opx) reaction boundary at which point Ga re-dissolves and orthopyroxene precipitates as the melt composition moves up-temperature along this boundary. The product of this process is a hybrid solid assemblage with garnet subordinate to orthopyroxene. For more mafic initial compositions (e.g. basalts) originally plotting in the Cpx field, it appears possible to avoid field boundaries involving garnet and shift in composition more directly toward peridotite, if assimilation is accompanied by a sharp increase in temperature. Considering published REE evidence (arguing against garnet playing a significant role in the genesis of many subduction-related magmas) in light of our results, it appears unlikely that peridotite assimilation by intermediate magmas under conditions of constant or increasing temperature is an important process in subduction zones. However, if assimilation is accompanied by an increase in temperature, our data do permit the derivation of high-Mg basalts from less refractory precursors (e.g. high-Al basalts) by peridotite assimilation.", "doi": "10.1007/BF00373719", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1989-07", "series_number": "3", "volume": "102", "issue": "3", "pages": "257-264" }, { "id": "authors:dpbgh-3j226", "collection": "authors", "collection_id": "dpbgh-3j226", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-154811132", "type": "article", "title": "Granite melt convecting in an experimental micro-magma chamber at 1050 \u00b0C, 15 kbar", "author": [ { "family_name": "Carroll", "given_name": "Michael R.", "clpid": "Carroll-M-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Equal masses of powdered granite and serpentinized peridotite packed into gold capsules with the\nmaterials separated by a sharp vertical boundary were held for between 0 minute and 11 hours at 1 050 \u00b0C,\n15 kbar to investigate contamination of hydrous granite melt by reaction with ultramafic rocks, as might occur\nnear the crust-mantle boundary. The shorter duration runs show a melting front advancing from the vertical\ngranite-peridotite boundary, where water is released from serpentine dehydration in the peridotite. The rate of\nadvance of the melt front decreases from over 10^(-4) cm/s in the first minutes to less than 10^(-5) cm/s after 1 hour,\nsuggesting that water diffusion to the melting front controls the melting rate. Experiments of longer duration\nshow evidence of convective flow of the granitic melt, and the flow features defined by graphite distributed in\nglass develop continuously with time. A 7 hour run shows a small concentration of residual quartz and feldspar\nat the far end of the capsule, with trails of graphite and entrained crystals tracing flow lines from the\ncrystal-rich area towards the center of the peridotite boundary, then around in a near-circular swirl in the\nlower half of the capsule. The graphite forms by reduction of the small amount of CO_2 in the starting materials.\nGlass analyses reveal initial steep compositional gradients adjacent to the peridotite (e.g. up to 2 wt.%\nMgO ; 0.1 wt.% in granite initially) but with increasing run duration the gradients become less steep and\ncompositional changes are spread throughout the main body of melt. After 11 hours, the granite is completely\nmelted, graphite which traced flow patterns in shorter runs has disappeared (presumably due to oxidation),\nand the granite is similar in composition to the starting material ; the most notable changes are an approximately\n1.0 wt.% increase in MgO (0.1 wt.% initially), 0.4 wt.% increase in FeO (from 0.64 wt.% initially), and\nless than 1 wt.% decreases in A1_2O_3 and SiO_2. The driving forces for the observed flow are not known but the\nmost likely explanations involve a small horizontal temperature gradient and/or small variations in melt water\ncontent.", "doi": "10.1127/ejm/1/2/0249", "issn": "0935-1221", "publisher": "E. Schweizerbart'sche Verlagsbuchhandlung", "publication": "European Journal of Mineralogy", "publication_date": "1989-05-03", "series_number": "2", "volume": "1", "issue": "2", "pages": "249-260" }, { "id": "authors:y5esg-w9m93", "collection": "authors", "collection_id": "y5esg-w9m93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-135635855", "type": "article", "title": "Interactions among magmas and rocks in subduction zone regions: experimental studies from slab to mantle to crust", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Carroll", "given_name": "Michael R.", "clpid": "Carroll-M-R" }, { "family_name": "Johnston", "given_name": "A. Dana", "clpid": "Johnston-A-D" }, { "family_name": "Rutter", "given_name": "Michael J.", "clpid": "Rutter-M-J" }, { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "van der Laan", "given_name": "Sieger R.", "clpid": "van-der-Laan-S-R" } ], "abstract": "Experiments have been conducted to study contamination of magmas in four environments : (1)\nabove subducted slabs, (2) below and (3) above the mantle-continental crust boundary, and (4) within shallow\ncrust. Reaction couples of peridotite or amphibolite with a sharp boundary against hydrous silicic melts\ndefine (1) diffusion profiles within contaminated melts and (2) crystalline reaction zones between the two\nmaterials. Mixtures of rocks peridotite-tonalite-granodiorite-granite with water define phase boundaries delineating\nthe extent of contamination of slab-derived melts rising through mantle and of crustal melts in contact\nwith peridotites {e.g., cumulates). Chemical diffusion in granite melts at 1.5 kbar, 810 \u00b0C is slow ; diffusion\nbetween hot, hydrous basalt-rhyolite at 10 kbar is faster. Convection occurs in H20-undersaturated granite\nmelt at 10-15 kbar, 920-1050 \u00b0C, during passage of a melting front through crystalline granite adjacent serpentinized\nperidotite, the source of H_2O; the convective motions transport contaminated melt away from the\ndiffusion zone, which therefore remains narrow. Rates of contamination and mixing of magmas near the\nmantle-crust boundary are likely to be much faster than in shallow crustal plutons. Slab-derived melts are\nricher in Ca/Mg than calc-alkaline rocks, and contamination with overlying mantle at depth makes them richer\nin Mg/Ca than calc-alkaline rocks. Near the mantle crust boundary, Ca/Mg in contamined melts is appropriate\nfor calc-alkaline rocks.", "doi": "10.1127/ejm/1/2/0165", "issn": "0935-1221", "publisher": "E. Schweizerbartsche Verlagsbuchhandlung", "publication": "European Journal of Mineralogy", "publication_date": "1989-05-03", "series_number": "2", "volume": "1", "issue": "2", "pages": "165-180" }, { "id": "authors:ys1eb-xzq45", "collection": "authors", "collection_id": "ys1eb-xzq45", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160223-132250411", "type": "article", "title": "Constraints on the origin of Archean trondhjemites based on phase relationships of N\u00fbk gneiss with H_2O at 15 kbar", "author": [ { "family_name": "Johnston", "given_name": "A. Dana", "clpid": "Johnston-A-D" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We report the T-X(H_2O) phase relations for the trondhjemitic N\u00fbk gneiss which comprises the principal component of the second phase of Archean (3.0\u20132.8 by) igneous activity in the Godth\u00e5b region of southwestern Greenland. A pressure of 15 kbar was chosen to place constraints on possible protoliths for trondhjemitic melts at lower crustal depths. Under H_2O-saturated conditions, a melting interval of \u223c135\u00b0 C separates the solidus at \u223c610\u00b0 C from the liquidus at 745\u00b0 C. H_2O-saturation at 15 kbar occurs at approximately 15.5 wt % H_2O. The H_2O-undersaturated liquidus extends along a curved path from \u223c745\u00b0 C at 15.5 wt % H_2O to \u223c1100\u00b0 C at 2% H_2O. Lower H2O contents were not investigated. At low H_2O contents (<6%) sodic plagioclase (Pl, An_(32)) is the liquidus phase followed at lower but still near-liquidus temperatures by quartz (Qz) and then garnet (Ga). At 6% H_2O, Ga replaces Pl on the liquidus and is joined at slightly lower temperatures by Pl and hornblende (Hb). The field for liquidus Ga extends to only \u223c7.5% H_2O where it is replaced by Hb which is the liquidus phase up to 13% H_2O. At all higher H_2O contents, epidote (Ep) is the first phase to crystallize, followed by biotite (Bi) at slightly lower temperatures. Following the standard inverse approach, the near-liquidus phase assemblages are interpreted as potential residues from which trondhjemitic melts could be extracted. At high melt H_2O contents (>7%), mafic residues consisting of some combination of Hb, Ga, Ep, and Bi are possible and could correspond to amphibolitic source rocks. At lower melt H_2O contents (< 5%), possible residues consist of Na-Pl+Qz\u00b1Ga and could correspond to an earlier generation of tonalitic-trondhjemitic rocks. However, such residues would not impart the highly fractionated REE patterns characteristic of Archean trondhjemites. If a first generation of tonalitic-trondhjemitic melts was generated by higher pressure partial fusion of eclogite and emplaced at 55 km depth, it would crystallize to an assemblage consisting almost entirely of Na-Pl+Qz with highly fractionated REE patterns. These rocks in turn could be partially melted to yield a second generation of trondhjemites which would inherit the highly fractionated REE patterns because neigher Pl nor Qz is capable of significantly fractionating HREE from LREE.", "doi": "10.1007/BF00399438", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1988-09", "series_number": "1", "volume": "100", "issue": "1", "pages": "35-46" }, { "id": "authors:pnsqq-9g997", "collection": "authors", "collection_id": "pnsqq-9g997", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-092211660", "type": "article", "title": "Magma genesis, plate tectonics, and chemical differentiation of the Earth", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Magma genesis, migration, and eruption have played prominent roles in the chemical differentiation of the Earth. Plate tectonics has provided the framework of tectonic environments for different suites of igneous rocks and the dynamic mechanisms for moving masses of rock into melting regions. Petrology is rooted in geophysics. Petrological and geophysical processes are calibrated by the phase equilibria of the materials. The geochemistry of basalts and mantle xenoliths demonstrates that the mantle is heterogeneous. The geochemical reservoirs are related to mantle convection, with interpretation of a mantle layered or stratified or peppered with blobs. Seismic tomography is beginning to reveal the density distribution of the mantle in three dimensions, and together with fluid mechanical models and interpretation of the geoid, closer limits are being placed on mantle convection. Petrological cross sections constructed for various tectonic environments by transferring phase boundaries for source rocks onto assumed thermal structures provide physical frameworks for consideration of magmatic and metasomatic events, with examples being given for basalts, andesites, and granites at ocean-continent convergent plate boundaries, basalts and nephelinites from a thermal plume beneath Hawaii, kimberlites in cratons, nephelinites from continental rifts, and anorogenic granites. The fluid dynamics of rock-melt-vapor systems exerts strong control on igneous processes and chemical differentiation. Unravelling the processes during subduction remains one of the major problems for understanding mantle heterogeneities and the evolution of continents.", "doi": "10.1029/RG026i003p00370", "issn": "8755-1209", "publisher": "American Geophysical Union", "publication": "Reviews of Geophysics", "publication_date": "1988-08", "series_number": "3", "volume": "26", "issue": "3", "pages": "370-404" }, { "id": "authors:q0n8h-sk054", "collection": "authors", "collection_id": "q0n8h-sk054", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-135152446", "type": "article", "title": "Solidus curves, mantle plumes, and magma generation beneath Hawaii", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The eruption of nepheline-normative lavas in the early and late stages of formation of the large Hawaiian tholeiite shields is well established, as is the conclusion that volatile components are involved in the genesis of these alkaline lavas. For magmas to be generated, the source materials must be transported across their solidus curves. Solidus curves for volatile-free peridotite and for peridotite-C-H-O provide the depth-temperature framework for the sites of magma generation. The assumption (controversial) that garnet remains in the source material locates the major melting region in plume material at depths of about 80 km, with isotherms in plume center exceeding 1500\u00b0C. The plume carries traces of volatile components from depths greater than 300 km. These dissolve in a trace of interstitial melt as the plume crosses the solidus for peridotite-C-H-O at depths decreasing from 350 km to about 150 km with distance from the plume axis. The volatile-charged melt, enriched in incompatible elements, is swamped by the picrites generated in the major melting region. From the outer portions of the plume, the volatile-rich melt enters the lithosphere at 80\u201390 km depth, where the change in rheology retards its upward percolation. This magma (remaining in equilibrium with peridotite) is carried toward the solidus for peridotite-C-H-O, changing composition toward nephelinite; evolution of vapor as magma approaches the solidus may facilitate intermittent crack propagation, releasing the nephelinitic magmas for eruption from depths of 75\u201385 km. Movement of the lithosphere plate over the rising plume establishes asymmetry. Eruption of nephelinitic magmas on the upstream side of the plume (early volcanism) may be suppressed or very close in time and space to eruption of alkaline lavas and tholeiites. On the downstream side (late volcanism), eruption of nephelinites is delayed by lateral transport away from the main melting region.", "doi": "10.1029/JB093iB05p04171", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research B", "publication_date": "1988-05-10", "series_number": "B5", "volume": "93", "issue": "B5", "pages": "4171-4181" }, { "id": "authors:ny2zc-yj744", "collection": "authors", "collection_id": "ny2zc-yj744", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141217-094908984", "type": "article", "title": "Flow in an experimental micro\u2013magma chamber", "author": [ { "family_name": "Carroll", "given_name": "Michael R.", "clpid": "Carroll-M-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The chemical evolution and eruptive behavior of magmas may be controlled largely by convective processes within magma chambers. According to a recent National Research Council Report [Committee on Physics and Chemistry of Earth Materials, 1987], \"the style of convection itself, whether it is turbulent, laminar, large-scale, of multiple scales, tiered, or localized and intermittent, is very much at question.\" In the U.S. National Report to the International Union of Geodesy and Geophysics, Marsh [1987] reviewed recent theoretical and experimental developments related to the style of convection in magma chambers, noting both significant quantitative advances and also the many remaining uncertainties. With regard to double-diffusive convection, he stated \"as ever, the critical question concerns whether or not actual magma chambers convect in this style.\" Similarly, Spera et al. [1986] , in discussion of double-diffusive convection, cautioned against \"applying results from saltwater tanks to magma chambers.\"", "doi": "10.1029/88EO00168", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1988-05-10", "series_number": "19", "volume": "69", "issue": "19", "pages": "579-588" }, { "id": "authors:anbmm-a5f94", "collection": "authors", "collection_id": "anbmm-a5f94", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160223-130529771", "type": "article", "title": "Interaction of granitic and basic magmas: experimental observations on contamination processes at 10 kbar with H_2O", "author": [ { "family_name": "Johnston", "given_name": "A. Dana", "clpid": "Johnston-A-D" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experiments designed to simulate the interaction of juxtaposed rhyolitic and basic magmas were conducted at 10 kbar with H_2O, using reaction-couples consisting of Westerly granite (WG) against basalt (DW-1) and WG against a synthetic mafic glass (SMG, enriched in MgO and Na_2O relative to DW-1). Each couple was run with \u223c5 and \u223c10 wt% H_2O corresponding respectively to H_2O-undersaturated and H_2O-oversaturated conditions. Experiments were run for 42\u201344 h at 920\u00b0 C, above the liquidus of WG and within the melting intervals of DW-1 and SMG. WG was run above the basic material in all but one experiment. The composition of the granitic melt was altered only through material exchange with the adjacent basic melts, whereas that of the basic melts also changed (relative to the bulk basic composition) due to partial crystallization. Some crystallization also occurred within the zone of interaction. For control, the basic compositions were also run alone under the same conditions as the reaction-couple experiments. The crystalline phase assemblages in the basic ends of the coupled experiments differed from those produced from the basic materials alone, demonstrating interaction with the granite melt. Moreover, compositional gradients within the basic ends of coupled experiments are indicated by changes in phase assemblage and compositions with distance from the interface with WG. Microprobe analyses of glass collected along the length of the capsules confirm published observations that alkali diffusion is very fast: K_2O and Na_2O homogenized throughout the capsules in less than the two-day run times. This, coupled with the fact that introduction of K_2O into SMG stabilized biotite, produced the result that after interaction the bulk basic material (melt+crystals) contained more K_2O than the coexisting felsic melt. Only very gentle gradients for CaO, FeO, and MgO are preserved in our experiments, in contrast with published anhydrous results, suggesting that the difference in activity coefficients for these components between basic and felsic melts is reduced by the introduction of H_2O. Gradients for SiO_2 and Al_2O_3 are of comparable length to those of the divalent cations, confirming earlier results that the diffusivities of the network-formers limit the rate of diffusion of Ca, Fe, and Mg.", "doi": "10.1007/BF00375185", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1988-03", "series_number": "3", "volume": "98", "issue": "3", "pages": "352-362" }, { "id": "authors:nf4h8-8nh70", "collection": "authors", "collection_id": "nf4h8-8nh70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-082006003", "type": "article", "title": "Experimental calibration of hornblende as a proposed emprical geobarometer", "author": [ { "family_name": "Rutter", "given_name": "Michael J.", "clpid": "Rutter-M-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The recent Eos report by Anderson [1987] reviewed prospects for using dated granitoid plutons as crustal nails in the reconstruction of descent or ascent of deformed crust during orogenic processes, if suitable geobarometers could be established. Hammarstrom and Zen [1986] and Hollister et al [1987] have proposed an empirical geobarometer for calcalkaline plutonic rocks of tonalite and granodiorite composition based on the total Al content (Air) of calcic hornblendes. This proposition has generated considerable interest.", "doi": "10.1029/88EO00058", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1988-02-09", "series_number": "6", "volume": "69", "issue": "6", "pages": "86-87" }, { "id": "authors:7avsp-61335", "collection": "authors", "collection_id": "7avsp-61335", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-095530937", "type": "article", "title": "Melting of vapour-absent tonalite at 10 kbar to simulate dehydration\u2013melting in the deep crust", "author": [ { "family_name": "Rutter", "given_name": "Michael J.", "clpid": "Rutter-M-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Granitoids may be formed by differentiation of mantle-derived basalts, by partial fusion of crustal rocks, or by interaction of melts from these two sources. Except in special circumstances, the amount of pore fluid in the deep continental crust is likely to be so small that partial melting of rocks will take place under vapour-absent conditions, with water becoming available through dehydration\u2013melting reactions. Here we present the results of experiments in which garnet tonalite is melted at 10 kbar in the absence of vapour. Between 825 and 900 \u00b0C the biotite melting reaction produces 20% melt; by 1,000 \u00b0C hornblende has melted, yielding 35% melt. As a melt fraction of 30\u201350% is required before a granodioritic melt can be segregated from its source rock our results imply that, whereas migmatites may be generated at typical high-grade metamorphic temperatures of 825 \u00b0C, the segregation of large-volume granitoid magmas from orthogneisses requires temperatures greater than 950 \u00b0C. In the absence of large amounts of externally-derived aqueous fluid, underplating or emplacement of hot basalt into the crust is required to raise the temperature sufficiently for magma segregation.", "doi": "10.1038/331159a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1988-01-14", "series_number": "6152", "volume": "331", "issue": "6152", "pages": "159-160" }, { "id": "authors:4f9h9-cz267", "collection": "authors", "collection_id": "4f9h9-cz267", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160308-123124839", "type": "article", "title": "Volcanic Rocks: Boundaries from experimental petrology", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Volcanoes are the surface manifestation of the process of chemical differentiation of the Earth. Experimental\npetrology calibrates the conditions for partial melting of various rocks, and defines the compositions of\nmelts derived by partial melting and the paths of crystallization of magmas under varied conditions. Experimental\nresults provide phase boundaries that constrain the sites of partial melting in the Earth's interior, given sufficient\ninformation about the source materials at depth and the geotherm as a function of tectonic environment and time.\nThe petrogenesis of basalts requires comprehension of the phase relationships for mantle peridotite as well as the\nderivative basalts. The effect of volatile components C-O-H on melting elucidates the origin of nephelinites\nassociated with hot-spot oceanic basalts, and the origin of kimberlites, nephelinites and carbonatites in cratonic\nregions. At convergent plate boundaries, the devolatilization of subducted oceanic crust influences magma generation\nin overlying mantle wedge and continental crust, preludes to the eruption of andesites and rhyolites. Experiments\non hybridization are applicable to the complex interactions between magmas from various sources that occur\nin this environment.", "issn": "0015-8186", "publisher": "Deutsche Mineralogische Gesellschaft", "publication": "Fortschritte der Mineralogie", "publication_date": "1987-12", "series_number": "2", "volume": "65", "issue": "2", "pages": "249-284" }, { "id": "authors:emkh3-fxt48", "collection": "authors", "collection_id": "emkh3-fxt48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-091148433", "type": "article", "title": "Discussion of recent papers on carbonated peridotite, bearing on mantle metasomatism and magmatism", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The solidus temperature for peridotite-CO_2 drops sharply within a narrow temperature interval, with increasing pressure, to an invariant point where dolomite becomes stable at the solidus. This geometry presents a barrier to some volatile-charged magmas rising through the lithosphere, with many petrological applications. The phase relationships are based on results in the model system CaO-MgO-SiO_2-CO_2, and peridotite-CO_2-H_2O. Two published sets of experimental results for the solidus of amphibole-dolomite-peridotite are here interpreted in terms of the topology of the system peridotite-CO_2-H_2O, with the conclusion that the two results yield quite different values for the pressure of the significant invariant point in peridotite-CO_2: 17 kbar or 27 kbar (equivalent to 30 km in the upper mantle). Better definition of this pressure, and clarification of the topology of the intersecting stability fields for dolomite, amphibole and phlogopite with the peridotite-vapor solidus, are essential for understanding magmatic and metasomatic processes in the lithosphere, and the petrogenesis of alkaline magmas and associated carbonatites.", "doi": "10.1016/0012-821X(87)90213-5", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1987-04", "series_number": "3-4", "volume": "82", "issue": "3-4", "pages": "391-397" }, { "id": "authors:a0npw-f7023", "collection": "authors", "collection_id": "a0npw-f7023", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160223-110636413", "type": "article", "title": "The phlogopites from the Jacupiranga carbonatite intrusions", "author": [ { "family_name": "Gaspar", "given_name": "Jos\u00e9 C.", "clpid": "Gaspar-J-C" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Electron microprobe analyses of phlogopites from five carbonatite intrusions (C_1 oldest, to C_5 youngest) constituting the carbonatite plug in the Jacupiranga complex support previous conclusions based on magnetite analyses that C_2 to C_5 represent a trend of differentiation, and that C_1 has different chemical characteristics. All analyzed grains are zoned but no systematic zoning trends occur. The FeO/(FeO + MgO) ratio is very low (0.065 to 1.2), MgO is high (22.5 to 28.2%), TiO_2 is very low (up to 0.44w%), BaO may be very high (up to 10.3 w%), and Na_2O may be as high as 2.77 w%. With decreasing age from C_2 to C_5, MgO increases. Phlogopites from a banded reaction rock between carbonatite and jacupirangite are similar to, but not related to the phlogopites of the adjacent carbonatite. Compared with other carbonatite micas, the MgO-rich, TiO_2-poor Jacupiranga phlogopites present one of the less evolved compositions, similar to those in mantle peridotites. Carbonatite micas are generally lower in TiO_2 than BaO-rich micas from other rocks.", "doi": "10.1007/BF01164485", "issn": "0930-0708", "publisher": "Springer", "publication": "Mineralogy and Petrology", "publication_date": "1987-04", "series_number": "2", "volume": "36", "issue": "2", "pages": "121-134" }, { "id": "authors:m0gka-hs942", "collection": "authors", "collection_id": "m0gka-hs942", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160111-155022574", "type": "article", "title": "Discussion of recent papers on carbonated peridotite, bearing on mantle metasomatism and magmatism: response", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "I agree with Eggler [1] that there is no discrepancy\nin the \"10-kbar difference in pressure\nbetween the pseudoinvariant point H_2 of Olafsson\nand Eggler [2] and an invariant point I_6 in CaO-\nMgO-SiO_2-CO_2\" if the topology shown in his Fig.\n1 is established. My discussion [3], however, was\nmore concerned with the difference of about 8\nkbar between the points H_2, related to the range\nof amphibole stability, in the only two experimental\nstudies reported on the solidus for dolomite-amphibole-\nperidotite [2,4], which are reproduced\nin my Fig. 1A and 1B [3].", "doi": "10.1016/0012-821X(87)90215-9", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1987-04", "series_number": "3-4", "volume": "82", "issue": "3-4", "pages": "401-402" }, { "id": "authors:ngz25-9nm70", "collection": "authors", "collection_id": "ngz25-9nm70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141217-095712080", "type": "article", "title": "1986 James B. Macelwane Awards", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Stolper", "given_name": "Edward", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "I can think of few things more pleasurable than introducing a young scientist whose research has enhanced his visibility to such an extent that his or her image is clearly distinguishable from among the large number of young scientists publishing excellent research these days.\n\nNormally, the recipient of a young scientist award is in a state approaching shock, with mixed feelings of pride and humility and appreciation for all those who guided him or her on the way. For Ed Stolper, however, the situation is different, and he is sitting here quite calmly. Although he is only 33 years old, his image shines brightly enough that it has received attention previously\u2014He was awarded the Clarke Medal of the Geochemical Society in 1985, and he shared the Newcomb Cleveland Prize in 1985 with Sally Rigden and Tom Ahrens for the best 1984 paper in Science. Today it is the Macelwane Award of the American Geophysical Union, and there are still several tomorrows before his age disqualifies him as a young scientist, making it necessary for him to start getting down to serious, mature research.", "doi": "10.1029/EO068i003p00042-01", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1987-01-20", "series_number": "3", "volume": "68", "issue": "3", "pages": "42-43" }, { "id": "authors:060sv-8qj58", "collection": "authors", "collection_id": "060sv-8qj58", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230105-204018447", "type": "article", "title": "Caltech Applauds Crafoord Laureate", "author": [ { "family_name": "Kamb", "given_name": "Barclay", "clpid": "Kamb-B" }, { "family_name": "Vogt", "given_name": "Rochus", "clpid": "Vogt-R-E" }, { "family_name": "Wyllie", "given_name": "Peter", "clpid": "Wyllie-P-J" }, { "family_name": "Goldberger", "given_name": "Marvin", "clpid": "Goldberger-M-L" }, { "family_name": "Fowler", "given_name": "Willy", "clpid": "Fowler-W-A" }, { "family_name": "Greenstein", "given_name": "Jesse", "clpid": "Greenstein-J-L" }, { "family_name": "Sharp", "given_name": "Bob", "clpid": "Sharp-R-P" }, { "family_name": "Albee", "given_name": "Arden L.", "clpid": "Albee-A-L" } ], "abstract": "On November 20 friends and colleagues of Gerald J. Wasserburg gathered at Caltech's Athenaeum to honor him as recipient of the 1986 Crafoord Prize. Awarded annually by the Royal Swedish Academy of Sciences, the prize for work in mathematics, astronomy, geosciences, or biosciences is one of the scientific community's most prestigious honors. The award cited Wasserburg, the John D. MacArthur Professor of Geology and Geophysics, for his \"major impact on our knowledge of the universe, focusing on the origins and history of the solar system and its component bodies. His work has established a time scale for the development of the early solar system and the formation of the planets, the moons, and the meteorites.\"", "issn": "0013-7812", "publisher": "California Institute of Technology", "publication": "Engineering and Science", "publication_date": "1987-01", "series_number": "3", "volume": "50", "issue": "3", "pages": "14-19" }, { "id": "authors:jvjnf-x3y79", "collection": "authors", "collection_id": "jvjnf-x3y79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-160726707", "type": "article", "title": "Phase relationships of gabbro-tonalite-granite-water at 15 kbar with applications to differentiation and anatexis", "author": [ { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase relationships have been determined at 15 kbar with variable H_2O contents for\nthree rocks-a gabbro, a tonalite, and a muscovite granite-representing the compositional\ntrend of the calc-alkaline rock series. Experiments were conducted in 0.5-in. piston-cylinder\napparatus using Ag-Pd or Pt capsules. The results obtained are acceptable representations\nof the phase relationships for elucidation of petrological processes. Selected runs with 5% H_2O were completed using Au capsules to overcome the problem of iron loss, up to the\ntemperature limit of Au, for reliable electron microprobe analyses of glass, garnet, clinopyroxene,\namphibole, and plagioclase. No glasses could be analyzed in the gabbro. The\ndata provide K_D values as a function of temperature for pairs of coexisting minerals and\nliquid. The chemical variations are used to evaluate (1) the fractionation trends in hydrous\nmagmas at 55 km in thickened continental crust or uppermost mantle and (2) the products\nof anatexis of the thickened crust. At this depth, fractionation of hydrous basalt, or anatexis\nof gabbro and tonalite or their metamorphosed equivalents, appears to produce liquids\ndiverging from the calc-alkaline trend. Anatexis of granite produces a liquid less siliceous\nthan itself, with some chemical characteristics of syenite.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1986-03", "series_number": "3-4", "volume": "71", "issue": "3-4", "pages": "301-316" }, { "id": "authors:tq0dm-sjt71", "collection": "authors", "collection_id": "tq0dm-sjt71", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-152348571", "type": "article", "title": "Solubility of rare earth elements in carbonatite magmas, indicated by the liquidus surface in CaCO_3-Ca(OH)_2-La(OH)_3 at 1 kbar pressure", "author": [ { "family_name": "Jones", "given_name": "A. P.", "clpid": "Jones-A-P" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The system CaCO_3-Ca(OH)_2(CC-CH) represents a synthetic analog to a carbonatite magma. Addition of a light rare earth (RE) component La(OH)_3 (LH) gives a simple analog of a rare earth carbonatite. Liquidus relations for two joins were studied at 1 kbar pressure; CH-LH and (CC_(55)CH_(45))-LH. CH-LH is binary with a eutectic at CH_(79)LH_(21) and 710\u00b0C. Thejoin CC_(55) + CH_(45))-LH has a liquidus piercing point between CC and LH, at (CC_(55)CH_(45))_(60)LH_(40) and 700\u00b0C. Combining the new results with known results for CC-CH allows construction of a liquidus diagram for part of the join CC-CH-LH. A ternary eutectic between the primary liquidus fields for CH, CC and LH occurs near 610\u00b0C with estimated composition CC= 33%, CH= 47%, LH= 20%. The solubility of La(OH)_3 in the synthetic carbonatite magma increases with increase of CO_2/H_2O from 20% at the eutectic to 40% at the piercing point on the join (CC_(55)CH_(45))-LH. The solubility of La in synthetic carbonatite is high compared with that of silicates. P_2O_5, and S. The results show that REE can become concentrated to high levels by fractionation of carbonatites, as long as they are not removed by high temperature crystallization of apatite and monazite.", "doi": "10.1016/0883-2927(86)90040-5", "issn": "0883-2927", "publisher": "Elsevier", "publication": "Applied Geochemistry", "publication_date": "1986-01", "series_number": "1", "volume": "1", "issue": "1", "pages": "95-102" }, { "id": "authors:qz240-j9x69", "collection": "authors", "collection_id": "qz240-j9x69", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-130458302", "type": "article", "title": "Conditions for melting and metasomatism in the Earth's mantle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "If we know the compositions of mantle rocks at various\ndepths, and the geotherm in different tectonic environments, then the\nconditions for melting are defined by experimentally determined solidus\ncurves. The term \"metasomatism\" in crustal processes is defined as reaction\nby solution or vapors, not by melts or magmas, and the same definition\nshould apply to mantle processes (reaction with magmas is\n\"hybridizatian\"). H_2O, CO_2, or both are made available for metasomalic\nreaction at deep dissociation fronts, or by solidificatfon of volatile-charged\nmagmas. Regions eligible for metasomatism are limited by solidus curves\nabove which the melts dissolve volatile components. Beneath the lithosphere,\nthere can be no metasomatism between about 120 and 260 km,\nbecause melting intervenes. Solidification of kimberlitic magmas at the\nbase of continental lithosphere is a source of metasomatic fluids. Mantle\nmetasomatism is expected in several regions above subducted oceanic\nlithosphere, interspersed with magmatic events. Major differentiation of\nthe Earth is accomplished by melting, but metasomatism may cause significant\nredistribution of some elements.", "issn": "1336-8052", "publisher": "De Gruyter", "publication": "Geologica Carpathica", "publication_date": "1985-06", "series_number": "3", "volume": "36", "issue": "3", "pages": "323-335" }, { "id": "authors:7cgtv-btg72", "collection": "authors", "collection_id": "7cgtv-btg72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-153527640", "type": "article", "title": "Hybridization of magmas above subducted oceanic crust", "author": [ { "family_name": "Sekine", "given_name": "Toshimore", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Hydrous siliceous melts rising from subducted oceanic crust\nmay experience hybridization with overlying peridotite. Products of hybridization\nhave been explored in the synthetic system KAlSiO_4-MgO-SiO_2-H_2O. The phase diagrams were used to interpret phase relationships\ndetermined at 30 kbar for mixtures of granite, peridotite, and H_2O. Results\nindicate that solution of peridotite in hydrous, H_2O-undersaturated granitic\nliquid at 900 \u00b0C, 30 kbar, causes only small changes in liquid composition,\nand precipitation of phlogopite-garnet-websterite. Additional\nexperiments, set up with H_2O-undersaturated granite liquid in contact\nwith solid peridotite at 30 kbar, 850-1050 \u00b0C, produced hybrid reaction\nzones containing orthopyroxene and clinopyroxene in all runs, and one\nor more of garnet, phlogopite, and quartz in some runs. The hybridization\nprocess in subduction zones could produce discrete rock bodies dominated\nby pyroxenite (without olivine); there is a prospect that potassium could\nbecome concentrated into phlogopite-rich rocks. The heterogeneous rock\nlayer produced above subducted crust provides aqueous fluids expelled\nduring hybridization, which rise to generate in overlying mantle the\nH_2O-undersaturated basic magnesian magma which is the probable parent\nof the calc-alkalic rock series erupted at the volcanic front.", "issn": "1336-8052", "publisher": "De Gruyter", "publication": "Geologica Carpathica", "publication_date": "1985-06", "series_number": "3", "volume": "36", "issue": "3", "pages": "259-268" }, { "id": "authors:kjqyg-93860", "collection": "authors", "collection_id": "kjqyg-93860", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160223-092535770", "type": "article", "title": "Paragenetic Trends of Oxide Minerals in Carbonate-rich Kimberlites, with New Analyses from the Benfontein Sill, South Africa", "author": [ { "family_name": "Jones", "given_name": "A. P.", "clpid": "Jones-A-P" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The relationship among kimberlites, carbonate-rich bodies associated with them, and the carbonatites associated with alkalis rock complexes are reviewed. Particular attention is paid to the parageneses of oxide minerals in six carbonate-kimberlites: Peuyuk, Tunraq, Wesselton, Liqhobong, De Beers, and Benfontein. New analyses of spinel, limonite, and perovskite from the lower Benfontein Sill, are consistent with previous reports and can be divided into (1) early macrocrysts and cores of grains, and (2) late rims and groundmass grains. The evolution of a carbonate-rich residuum with progressive crystallization appears to be typical of carbonate-rich kimberlite magmas, and is texturally related to the two stages of oxide precipitation in these carbonate-kimberlites. Thus, early Mg-ilmenite and Cr-rich spinel are separated by reaction textures and carbonate from later Mg-Al-titanomagnetite, perovskite, and accessory utile and apatite. The spinels span a large range in composition from Mg-Al-chromite to Mg-Al-titanomagnetite, with an intermediate gap. This simplified paragenetic scheme, and in particular the spinel trend, is repeated in the five other carbonate-kimberlites reviewed. It may be representative of the hypabyssal kimberlites in general, and others where fluidization processes did not completely disrupt the crystallization sequence.", "doi": "10.1093/petrology/26.1.210", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1985-02", "series_number": "1", "volume": "26", "issue": "1", "pages": "210-222" }, { "id": "authors:5ar9h-kq222", "collection": "authors", "collection_id": "5ar9h-kq222", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-075732039", "type": "article", "title": "Sources of granitoid magmas at convergent plate boundaries", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Source rocks for magmas in subduction zones include subducted oceanic crust, mantle peridotite, and metamorphic rocks of continental crust. Phase relationships for these materials, including the compositions of liquids developed at various pressures, temperatures, and with H_2O and CO_2, provide a starting point for the petrogenesis of granitoid intrusions. Four thermal structures are obtained by combinations of warm or cool subducted oceanic crust, and cool or warm overlying mantle. These encompass the range of dehydration and melting sites and processes likely to occur in subduction. Petrological structures derived by combining major rock structures with the assumed thermal structures and the phase relationships of materials indicate that initial magma generation in any of the three major source rocks may be followed by a sequence of events leading to the intrusion of granitoid magmas into continental crust. Magmas of different compositions may rise independently from different sources at different depths, introducing the prospect of hybridization and magma mixing in the mantle and continental crust. Many granitoid intrusions are initiated by the transfer of heat and magma from below the continental crust.", "doi": "10.1016/0031-9201(84)90030-X", "issn": "0031-9201", "publisher": "Elsevier", "publication": "Physics of the Earth and Planetary Interiors", "publication_date": "1984-10", "series_number": "1-3", "volume": "35", "issue": "1-3", "pages": "12-18" }, { "id": "authors:p976t-h7w89", "collection": "authors", "collection_id": "p976t-h7w89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-073753965", "type": "article", "title": "Minor elements in perovskite from kimberlites and distribution of the rare earth elements: An electron probe study", "author": [ { "family_name": "Jones", "given_name": "Adrian P.", "clpid": "Jones-A-P" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "We report REE and minor element distributions for perovskites from seven kimberlites (South Africa and U.S.A.). The REE (1.6\u20136.3 oxides wt.%) are always strongly light REE enriched, often with Ce > La (chondrite-normalized), and show an expected close correlation with whole-rock analyses. Where examined, perovskite contains far more REE than coexisting apatite, by about an order of magnitude. Calculations indicate that iron is mostly present as Fe^(3+) and is low (1.0\u20132.9 wt.% Fe_2O_3) compared with perovskite from carbonatite complexes such as Oka (4.4 wt.% FeO [3]). In addition to established Nb (0.3\u20131.7 oxide wt.%), geochemically interesting elements encountered include Zr (up to 1.5 oxide wt.%), Ba and Sr (up to 0.2, 0.4 oxide wt.% respectively). Specific geological applications suggest a possible genetic link between Wesselton pipe and Benfontein Sills kimberlites, and that carbonate-rich dikes in the Premier mine were derived from kimberlites. The overall similarities with incompatible element-rich titanates in veined mantle peridotites suggest a more direct link between kimberlite magmatism and mantle metasomatism.", "doi": "10.1016/0012-821X(84)90078-5", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1984-07", "series_number": "1", "volume": "69", "issue": "1", "pages": "128-140" }, { "id": "authors:kqnza-mpq22", "collection": "authors", "collection_id": "kqnza-mpq22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141113-113355100", "type": "article", "title": "Constraints imposed by experimental petrology on possible and impossible magma sources and products", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Osmaston", "given_name": "M. F.", "clpid": "Osmaston-M-F" }, { "family_name": "Morrison", "given_name": "M. A.", "clpid": "Morrison-M-A" } ], "abstract": "Experimental petrology can be used in forward and inverse approaches. The forward approach defines the compositions of liquids generated by partial melting of possible source rocks at various depths. The inverse approach determines conditions for multiple-mineral saturation at the liquidus of primitive magmas, correlates them with residual minerals of possible source rocks, and thus provides estimates of depths and temperatures required for their derivation. Review of a selection of forward and inverse results is followed by evaluation of petrological and geophysical processes in layered mantle and in subduction zones. Physical constraints imposed by solidus curves and geotherms present problems for models that derive basalts from deep mantle reservoirs, separated from overlying convecting layers. Magmas from mantle are limited to compositions less siliceous than basaltic andesite, with rare exceptions. Granite liquids cannot be generated from normal peridotite, nor from oceanic crust at mantle pressures in subduction zones. In continental crust, hydrous granite liquid is generated at depths of less than 30 km. Basaltic andesite and picritic basalt are parental magmas for the calc-alkaline series. Andesite is not primary from subcontinental depths, and can be generated as liquid in continental crust only if temperatures exceed about 1100 degrees C. Calc-alkaline magmas may contain components from mantle peridotite, subducted oceanic crust, and continental crust.", "doi": "10.1098/rsta.1984.0003", "issn": "1364-503X", "publisher": "Royal Society of London", "publication": "Philosophical Transactions A: Mathematical, Physical and Engineering Sciences", "publication_date": "1984-04-27", "series_number": "1514", "volume": "310", "issue": "1514", "pages": "439-456" }, { "id": "authors:wc360-pqe41", "collection": "authors", "collection_id": "wc360-pqe41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160219-092721218", "type": "article", "title": "The alleged kimberlite-carbonatite relationship: evidence from ilmenite and spinel from Premier and Wesselton mines and the Benfontein sill, South Africa", "author": [ { "family_name": "Gaspar", "given_name": "Jose C.", "clpid": "Gaspar-J-C" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Carbonate-rich, SiO_2-poor residua are developed in some kimberlites solidifying as ocelli, layers, or discrete dikes which satisfy petrographic definitions of carbonatite. Arguments that these rocks have mineralogies, antecedents, and comagmatic rocks differing from those of the carbonatites in alkaline rock complexes, including the specific observation that kimberlites and carbonatites contain ilmenites and spinels of different composition, have been used to refute the \"alleged kimberlite-carbonatite relationship\". New microprobe analyses of ilmenites and spinels from carbonate-rich rocks associated with kimberlites in three South African localities correspond to spinels and ilmenites of carbonatites from alkalic complexes, or have characteristics intermediate between those of carbonatites and kimberlites. The ilmenites are distinguished from kimberlite ilmenites by higher MnO, FeTiO_3, and Nb_2O_5, and by negligible Cr_2O_3. The spinels are distinguished from kimberlite spinels by their Al_2O_3 and Cr_2O_3 contents. There is clearly a genetic relationship between the kimberlites and the carbonate-rich rocks, despite the observation that their ilmenites and spinels are distinctly different, which indicates that the same observation is not a valid argument against a petrogenetic relationship between kimberlites and carbonatites. These rocks are among the diverse products from mantle processes influenced by CO_2, and we believe that the petrogenetic links among them are forged in the upper mantle. We see insufficient justification to deny the name \"carbonatite\" to carbonate-rich rocks associated with kimberlites if they satisfy the petrographic definition in terms of major mineralogy.", "doi": "10.1007/BF00371703", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1984-02", "series_number": "2", "volume": "85", "issue": "2", "pages": "133-140" }, { "id": "authors:azc4c-45q11", "collection": "authors", "collection_id": "azc4c-45q11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160321-152554001", "type": "article", "title": "The effect of carbon dioxide on phase relationships for synthetic lherzolite and harzburgite", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The system CaO-MgO-SiO_2-CO_2 includes mineral assemblages corresponding to model lherzolite:\nforsterite(Fo) + orthopyroxene(Opx) + clinopyroxene(Cpx), and model harzburgite: Fo + Opx, as\nwell as model websterite and wehrlite. When fully carbonated, the peridotites are converted to\nlimestones: dolomite(Do) + magnesite(Mc) + quartz(Qz), or Mc + Qz. When partly carbonated, the\nperidotites are converted to carbonate-lherzolite and magnesite-harzburgite, which cannot coexist\nwith CO_2. Available experimental and calculated reaction data are presented for carbonatc-lherzolite:\n(6) Opx + Do = Cpx + Fo + CO_2 and (6A) Opx + Cc = Cpx + Fo + CO_2, where Do is dolomite and its\nsolid solution, and Cc is magnesium calcite; for magnesite-harzburgite: (3) MC+ En = Fo + CO_2; for\nwebsterite + carbonate: (0) Mc + Cpx = Do + Opx and (01) Do + Cpx = Cc + Opx; and for\ncarbonate-wehrlite: (9)Do + Cpx = Fo + Cc + CO_2. Conditions for the occurrence of\ndolomite(stoichiome trjc)-lherzolite are evaluated. Comparison of fossil geotherms deduced from\nkimbe rlite nodules with the phase diagrams for model harzburgite and lherzolite, and solidus curves\nwith H_2O present, indicates that partially melted lherzolite may coexist with solid magnesiteharzburgite\nbetween about 175 and 195 km depth. Dissociation of magnesite could disrupt the\nharzburgite nodules during eruption, distributing low-calcium garnet through kimberlite.", "issn": "0016-7746", "publisher": "Nederlands Geologisch Mijnbouwkundig Genootschap", "publication": "Geologie en mijnbouw", "publication_date": "1984", "volume": "63", "pages": "213-219" }, { "id": "authors:dqprh-nge96", "collection": "authors", "collection_id": "dqprh-nge96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-084426026", "type": "article", "title": "Low-temperature glass quenched from a synthetic, rare earth carbonatite; implications for the origin of the Mountain Pass Deposit, California", "author": [ { "family_name": "Jones", "given_name": "Adrian P.", "clpid": "Jones-A-P" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Synthetic carbonatite magmas are represented by\nmelts in the system CaO-CO_2H_2O (Wyllie and Tuttle,\n1960), and the relation between carbonatites and\nsilicate magmas has been investigated by addition of\nother components (e.g., Wyllie, 1966, 1978). We are\npresently determining the phase relations in a. series\nof systems involving CaO-CaF_2-La(OH)_3-CO_2-H_2O\nand other components in an effort to delineate the\nconditions for the precipitation of rare earth carbonates\nand fluocarbonates (bastnaesite-type minerals)\nfrom synthetic carbonatite magmas. As a supplement\nto the construction of phase diagrams in systems characterized\nby limited numbers of com portents, we have\nstudied a more complex bulk composition which we\nbelieve approximates that of the Sulphide Queen carbonatite\nat Mountain Pass, California-prior to crystallization.", "doi": "10.2113/gsecongeo.78.8.1721", "issn": "0361-0128", "publisher": "Society of Economic Geologists", "publication": "Economic Geology", "publication_date": "1983-12", "series_number": "8", "volume": "78", "issue": "8", "pages": "1721-1723" }, { "id": "authors:h5zns-m0410", "collection": "authors", "collection_id": "h5zns-m0410", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-151840565", "type": "article", "title": "Carbonation of peridotites and decarbonation of siliceous dolomites represented in the system CaO-MgO-SiO_2-CO_2 to 30 kbar", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "W.-L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Otto", "given_name": "Jens", "clpid": "Otto-J" }, { "family_name": "Byrnes", "given_name": "A. P.", "clpid": "Byrnes-A-P" } ], "abstract": "The decarbonation of siliceous dolomite produces rocks including the minerals forsterite, orthopyroxene and clinopyroxene, characteristic of peridotites. Selected reactions in the system CaO-MgO-SiO_2 \u2013CO_2 are reviewed and published data at crustal and mantle pressures are compared with previously unpublished experimental results between 15 and 30 kbar for five reactions: (0) magnesite + clinopyroxene = dolomite + orthopyroxene; (1) magnesite + quartz = enstatite + CO_2; (5) dolomite + orthopyroxene + quartz = clinopyroxene + CO_2; (3) magnesite + enstatite = forsterite + CO_2; (6) dolomite + orthopyroxene = clinopyroxene + forsterite+ CO_2. Reactions (0), (1) and (5) meet at an invariant point near 1090\u00b0C and 34 kbar. Reactions (3) and (6) represent the carbonation of model harzburgite and Iherzolite, respectively. Dolomites in reaction (6) contain more than 70 wt.% CaCO_3, at temperatures below the crest of the calcite-dolomite solvus, they are magnesian calcites. Phase relationships for carbonated model peridotites in the presence of H_2O, compared with estimated depths and temperatures of equilibration of xenoliths from the Premier Mine kimberlite, indicate that within limited depth intervals solid magnesite-harzburgite can coexist with partially melted lherzolite. Eruption of kimberlite could transport xenoliths of Iherzolite and magnesite-harzburgite. Experiments indicate that the magnesite dissociates within minutes during uprise. This observation is consistent with the proposal of Boyd and Gurney that low-calcium garnets in kimberlites of the Kaapvaal-Rhodesian craton are produced by disruption of magnesite disseminated through depleted harzburgites in the roots of the craton, within the diamond stability field.", "doi": "10.1016/0040-1951(83)90194-4", "issn": "0040-1951", "publisher": "Elsevier", "publication": "Tectonophysics", "publication_date": "1983-12", "series_number": "1-3", "volume": "100", "issue": "1-3", "pages": "359-388" }, { "id": "authors:wn65q-d7457", "collection": "authors", "collection_id": "wn65q-d7457", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-085338860", "type": "article", "title": "Ilmenite (high Mg,Mn,Nb) in the carbonatites from the Jacupiranga Complex, Brazil", "author": [ { "family_name": "Gaspar", "given_name": "Jos\u00e9 C.", "clpid": "Gaspar-J-C" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Ilmenite occurs rarely in the carbonatite plug (five separate intrusions) of the Jacupiranga\nComplex, in the jacupirangite near the contacts, and in the banded reaction zones between\ncarbonatite and jacupirangite. Electron microprobe analyses reveal a wider range of\nilmenite compositions than previously reported from carbonatites, as solid solutions in\nFeTiO_3-MgTiO_3-MnTiO_3-Fe2O_3, with high-Nb ilmenites containing up to 3.68 wt.%\n(Nb_2O_5 + Ta_2O_5). A group of discrete primary ilmenites from one carbonatite is\ndistinguished by unusually high MnTiO_3 (MnO 15.1-19.6%); ilmenite inclusions in magnetites\nof the carbonatite intrusions are similar in composition to magnesian ilmenites\npreviously reported; other ilmenites (a few discrete grains, but mainly lamellae with some\ngranules associated with magnetite), have compositions that vary almost completely from\nFeTiO_3 to MgTiO_3, with less than 10% Fe_2O_3. Titanomagnetites (with Nb_2O_5 below\ndetection limits) in jacupirangite have ilmenite lamellae near and within the reaction zones,\nwith Nb_2O_5 increasing (Nb_2O_5 + Ta_2O_5 up to 0.95%) and Fe_2O_3 decreasing in ilmenite as\ncarbonatite is approached. Pentavalent Nb and Ta replace Ti in ilmenite, causing cation\ndeficiency. In coexisting magnetite and ilmenite, MgO and MnO partition preferentially\ninto ilmenite; MgO shows a regular pattern of distribution between ilmenite and magnetite,\nwhereas MnO is distributed irregularly. Coexisting magnetite and ilmenite (with low MgO\nand MnO) from the reaction rocks give equilibration temperatures of 570-595\u00b0C and\noxygen fugacities of 10^(-18.5) to 10^(-19.5) atmospheres. The ilmenites are distinguished from\nilmenites in kimberlites by high MnO, very low Cr_2O_3, and high (Nb_2O_5 + Ta_2O_5).", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1983-09", "series_number": "9-10", "volume": "68", "issue": "9-10", "pages": "960-971" }, { "id": "authors:s7yq7-76h68", "collection": "authors", "collection_id": "s7yq7-76h68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160219-083147638", "type": "article", "title": "Experimental Simulation of Mantle Hybridization in Subduction Zones", "author": [ { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experiments conducted at 30 kbar, 850-1050\u00b0C, in piston-cylinder apparatus simulate hybridization between hydrous siliceous magma rising from subducted oceanic crust into overlying peridotite. Gold capsules containing granite and peridotite powders separated by sharp boundaries, and H_2O, were run in vertical and horizontal positions. The aqueous vapor caused minor metasomatic changes in the peridotite until it was withdrawn into the melting granite, producing H_2O-undersaturated granite liquid adjacent sintered, anhydrous peridotite. Minerals developed in the hybrid reaction zones between liquid and peridotite are orthopyroxene and jadeitic clinopyroxene in all runs, and one or more of garnet, phlogopite, and quartz in some runs. (The granite liquid moves upwards relative to the peridotite even in runs of 27 hours.) In the longest runs of 120 hours the hybridization zone remains narrow, the body of granite liquid remains crystal-free and only slightly changed in composition (lower SiO_2, MgO increased from 0.1% to about 1.5%). The products are consistent with phase equilibria in synthetic model systems, and the system peridotite-granite-H_2O (determined using mixtures). The hybridization process in subduction zones would produce discrete rock bodies dominated by pyroxenites without olivine. Na is fixed in jadeitic clinopyroxene. K is fixed in phlogopite dispersed through the pyroxenite, but there is a prospect that it may become concentrated into phlogopite-rich rocks by crystal fractionation. Partial melting of these source rocks would generate magmas different from those generated in peridotite or subducted oceanic crust.", "doi": "10.1086/628802", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1983-09", "series_number": "5", "volume": "91", "issue": "5", "pages": "511-528" }, { "id": "authors:7f03k-wxh11", "collection": "authors", "collection_id": "7f03k-wxh11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-091328435", "type": "article", "title": "Presentation of the Roebling Medal of the Mineralogical Society of America for 1982 to Joseph V. Smith", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "If I had been given the chance to choose someone to\nintroduce for the Roebling Medal, my selection would\nhave been Joseph V. Smith. His creative research productivity\nidentifies him clearly as a mineralogical medallist.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1983-05", "series_number": "5-6", "volume": "68", "issue": "5-6", "pages": "649-650" }, { "id": "authors:ps9z8-nfj74", "collection": "authors", "collection_id": "ps9z8-nfj74", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-152837195", "type": "article", "title": "Phase relationships in the join grossularite-pyrope-7.5% H_2O at 30 KB", "author": [ { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experiments were conducted in piston-cylinder apparatus\nusing gels with added H_2O between 900\u00b0 and 1525\u00b0C. The synthesis results\nwere checked by two-stage reversal runs. Compositions of garnet (Ga) and\nclinopyroxene (Cpx) solid solutions were measured by microprobe. With\n7.5 percent H_2O, pyrope (Py) melts incongruently producing spinel (Sp),\nand grossularite (Gr) melts congruently, with brackets 1500\u00b0 to 1525\u00b0C\nand 1300\u00b0 to 1325\u00b0C, respectively. A field for Cpx + L has temperature\nmaximum on the liquidus at 1380\u00b0C, very near the composition Gr_2Py_1\nwhere the join diopside-Ca-Tscherrnak's molecule (Di-CaTs) crosses the\ngarnet join (33.3 mole percent Py). This field is bounded by two liquidus\npiercing points for the coexistence of Ga + Cpx + L with liquid compositions\nand temperatures of 25 mole percent Py-1275\u00b0C and 48 mole percent\nPy-1295\u00b0C. The Cpx field is bounded with decreasing temperature\nby a reaction interval for Cpx + Ga+ L and terminated at 1110\u00b0C by the\nreaction: Cpx_(ss) + L = Gr_(ss). At lower temperatures, solid solution in\ngarnets is continuous from grossularite to pyrope. The compositions of\nclinopyroxenes coexisting with liquid are near Gr_2Py_1 : with decreasing\ntemperature the Al_2O_3 content increases, and for bulk compositions richer\nin MgO the Cpx is enriched in enstatite (En) component. As Cpx reacts\nto produce Ga with decreasing temperature, the clinopyroxene component\nEn decreases, and CaTs increases. The results obtained with 7.5 percent\nH_2O present are compared in detail with the few previous studies in the\ndry system at 30 kb.", "doi": "10.2475/ajs.283.5.435", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1983-05", "series_number": "5", "volume": "283", "issue": "5", "pages": "435-453" }, { "id": "authors:a6nw0-qcz14", "collection": "authors", "collection_id": "a6nw0-qcz14", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160331-091422737", "type": "article", "title": "Acceptance of the Wollaston Medal", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The President presented the Wollaston Medal to\nProfessor Peter John Wyllie and said: \nWhen you enrolled as a student at St Andrews you intended to graduate in Physics or Chemistry. We owe it to the attractions of field trips and, more importantly, to the influence of the late Harald Drever that you were lured into Geology. Whilst you were still an undergraduate he enlisted you on two Greenland expeditions and, when you left St Andrews, he arranged for you to become a research assistant to O. F. Tuttle at Penn. State. From there you held two consecutive 1-year appointments at Leeds, first as research fellow in Chemistry, then as lecturer in Experimental Petrology in my own Department where you are still remembered as a prodigious and highly organised worker. Returning in the early 1960's to Penn. State as Associate Professor in Petrology, you became acting Head of Department of Geochemistry and Mineralogy before you moved on to become Professor of Petrology and Geochemistry at Chicago. More recently, you have become Chairman there of the Department of Geophysical Sciences.", "issn": "0016-7649", "publisher": "Geological Society", "publication": "Journal of the Geological Society", "publication_date": "1983-03", "series_number": "2", "volume": "140", "issue": "2", "pages": "328-329" }, { "id": "authors:a7c9r-0yc62", "collection": "authors", "collection_id": "a7c9r-0yc62", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160217-113539998", "type": "article", "title": "Effect of H_2O on Liquidus Relationships in MgO-Al_2O_3-SiO_2 at 30 Kilobars", "author": [ { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Dehydrated gels with compositions corresponding to mixtures of pyrope-enstatite, pyrope-quartz, and pyrope-quartz-corundum were sealed in platinum capsules and reacted in half-inch piston-cylinder apparatus at 30 kbar. Samples were pyrope composition with variable H_2O, and other compositions with 7.5 wt % H_2O. Highly aluminous metastable orthopyroxenes nucleated from and persisted in mixtures with compositions near pyrope. There is no univariant fusion curve for pyrope-H_2O. Pyrope dissolves incongruently in H_2O subsolidus, and a trace of liquid is produced near 1000\u00b0C. A univariant reaction: pyrope + forsterite + vapor = spinel + liquid was located at 1150 \u00b1 20\u00b0 C. The liquidus for pyrope with excess H_2O is at 1310\u00b0C. Orthopyroxenes coexisting with SiO_2-rich liquids contain 0.8-5.7% excess SiO_2 compared with MgSiO_3-Al_2O_3. Liquidus diagrams dry, with 7.5% H_2O, and with excess H_2O illustrate the effect of H_2O on the liquidus relationships. With increasing H_2O: the liquidus volume for Opx expands greatly at the expense of that for Qz, and slightly at the expense of Py; the volume for Fo expands significantly at the expense of that for Opx, and slightly at the expense of Py; liquid coexisting with Fo + Opx + Py is enriched in SiO_2 and Al_2O_3; liquid coexisting with Opx + Py + Qz is enriched greatly in SiO_2 and slightly in Al_2O_3; the range of liquid compositions coexisting with Opx + Py is greatly increased toward enrichment in SiO_2. These results provide boundaries for corresponding phase relationships in CaO-MgO-Al_2O_3-SiO_2-H_2O with applications to the effect of H_2O on partial fusion of subducted oceanic crust (quartz eclogite) and mantle peridotite.", "doi": "10.1086/628756", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1983-03", "series_number": "2", "volume": "91", "issue": "2", "pages": "195-210" }, { "id": "authors:dc2mg-brj80", "collection": "authors", "collection_id": "dc2mg-brj80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-110819188", "type": "article", "title": "Magnetite in the carbonatites from the Jacupiranga Complex, Brazil", "author": [ { "family_name": "Gaspar", "given_name": "Jose C.", "clpid": "Gaspar-J-C" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Electron microprobe analyses of magnetites from five carbonatite intrusions (C_1, oldest,\nto C_5, youngest) constituting the carbonatite plug in the Jacupiranga complex confirm\nprevious results from Jacupiranga giving compositions in the magnesioferrite-magnetite\nseries very close to Fe_3O_4. Magnetites from other carbonatites are similar with somewhat\nmore Ti and less Mg. MgO in Jacupiranga magnetites reaches no more than 10 wt.%. All\nanalyzed grains are zoned, with Fe_3O_4 increasing toward the rim. In magnetites from C_2 to\nC_5, Fe_2O_3 replacement is mainly by Al_2O_3 and less by TiO_2; in C_1 magnetites TiO_2\nreplacement is more important. Despite their limited range of compositions, the cores of\nmagnetites in each of the five intrusions are chemically distinct and distinguishable from\neach other as indicated by projections from within the Cr-free spinel prism, MgFe_2O_4-Mg_2TiO_4-MgAl_2O_4-Fe_3O_4-Fe_2TiO_4-FeAl_2O_4, and a plot of Mn ys. Mg. Magnetites from\nspecial locations such as dikes, banded reaction zones between carbonatite and jacupirangite,\nand in intergrowths with pyrite, are chemically related but distinct from the\ncarbonatite magnetites. The systematic chemical variation and zoning of magnetites in the\nfive carbonatite intrusions indicate magmatic origin. Magnetite crystals nucleated throughout\nthe crystallization interval of the carbonatites, but most of them show evidence of\nmarginal resorption. The oldest carbonatite, C_1, was probably derived from a magma\nsomewhat different chemically from those producing carbonatites C_2 through C_5. The\nprecipitation of carbonatite C_2 probably went to completion independently of C_3 through\nC_5, whereas carbonatites C_3 through C_5 probably were precipitated from successive\nbatches of magma representing a continuum in time and magmatic evolution.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1983-01", "series_number": "1-2", "volume": "68", "issue": "1-2", "pages": "195-213" }, { "id": "authors:1s0xn-pab16", "collection": "authors", "collection_id": "1s0xn-pab16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-141923132", "type": "article", "title": "Phase relationships in the system KAlSiO_4-Mg_2SiO_4-SiO_2-H_2O as a model for hybridization between hydrous siliceous melts and peridotite", "author": [ { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The system KalSiO_4-Mg_2SiO_4-SiO_2-H_2O includes model representatives of (1) hydrous siliceous magma from subducted oceanic crust \u2014 the eutectic liquid in KalSi_3O_8-SiO_2-H_2O, and (2) the overlying mantle peridotite \u2014 the assemblage forsterite+enstatite (Fo+En). In a series of partly schematic isobaric isothermal sections, the products of hybridization between the model materials at pressures between 20 and 30 kbar have been determined. The liquid dissolves peridotite components with little change in composition. Hybridization is not a simple mixing process, because of the incongruent melting of peridotitic assemblages with phlogopite (Ph). Hybridization causes solidification of the liquid, with products a sequence of three mineral assemblages: Ph, Ph+quartz (Qz), and Ph+En. The products represent an absolute geochemical separation and local concentration of all potassium from the liquid. Hybridization is accompanied by H_2O-saturation of melts, and evolution of aqueous fluid. Although there are significant differences between the melt composition and that of the magma rising from subducted oceanic slab, and between Fo+En and the mantle rock, extrapolation of the results suggests that the conclusions can probably be extended to mantle conditions with sodium in the melt, and jadeitic clinopyroxene included in the hybrid products.", "doi": "10.1007/BF01132066", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1982-12", "series_number": "4", "volume": "79", "issue": "4", "pages": "368-374" }, { "id": "authors:xtdt1-3r205", "collection": "authors", "collection_id": "xtdt1-3r205", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-153737413", "type": "article", "title": "The system granite-peridotite-H_2O at 30 kbar, with applications to hybridization in subduction zone magmatism", "author": [ { "family_name": "Sekine", "given_name": "T.", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experiments with mixtures of granite, peridotite and H_2O at 30 kbar were designed as a first step to test the hypothesis that the calc-alkaline igneous rocks of subduction zones are formed by differentiation of magmas derived by partial melting of hybrid rocks generated in the mantle wedge, by reaction between hydrous siliceous magma rising from subducted oceanic crust, and the overlying mantle peridotite. Experiments were conducted in gold capsules in half-inch diameter piston-cylinder apparatus. Results are presented in a 900\u00b0 C isotherm, and in a projection of vapor-present phase fields onto T-granite-peridotite. Isobaric solution of peridotite in hydrous, H_2O-undersaturated granite liquid at 900\u00b0 C causes only small changes in liquid composition, followed by precipitation of orthopyroxene until about half of the liquid has solidified; then orthopyroxene is joined by jadeitic clinopyroxene, garnet, and phlogopite. Phlogopite-garnet-websterite continues to be precipitated, with evolution of aqueous vapor, until all of the liquid is used up. The product of hybridization is a pyroxenite without olivine. The products of partial melting of this material would differ from products derived from peridotite because there is no olivine control, and the clinopyroxenes contain up to 7% Na_2O, compared with less than 1% Na_2O in peridotite clinopyroxenes. The reaction products are directly analogous to those in the model system KalSiO_4-Mg_2SiO_4-SiO_2-H_2O, where, with decreasing SiO_2 in the hydrous siliceous liquid, the field for phlogopite expands, and phlogopite instead of orthopyroxene becomes the primary mineral. If this occurs with less siliceous magmas from the subducted oceanic crust, there is a prospect for separation of discrete bodies of phlogopite-rock as well as phlogopite-garnet-websterite. We need to know the products of hybridization, and the products of partial melting of the hybrid rocks through a range of conditions.", "doi": "10.1007/BF00371296", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1982-12", "series_number": "3", "volume": "81", "issue": "3", "pages": "190-202" }, { "id": "authors:fpnqq-pd474", "collection": "authors", "collection_id": "fpnqq-pd474", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-142932486", "type": "article", "title": "The formation of mantle phlogopite in subduction zone hybridization", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" } ], "abstract": "Extrapolation and extension of phase equilibria in the model system KalSiO_4-Mg_2SiO_4-SiO_2-H_2O suggests that at depths greater than 100 km (deeper than amphibole stability), hybridism between cool hydrous siliceous magma, rising from subducted oceanic crust, and the hotter overlying mantle peridotite produces a series of discrete masses composed largely of phlogopite, orthopyroxene, and clinopyroxene (enriched in Jadeite). Quartz (or coesite) may occur with phlogopite in the lowest part of the masses. The heterogeneous layer thus produced above the subducted oceanic crust provides: (1) aqueous fluids expelled during hybridization and solidification, which rise to generate in overlying mantle (given suitable thermal structure) H_2O-undersaturated basic magma, which is the parent of the calc-alkalic rock series erupted at the volcanic front; (2) masses of phlogopite-pyroxenites which melt when they cross a deeper, high-temperature solidus, yielding the parents of alkalic magmas erupted behind the volcanic front; and (3) blocks of phlogopite-pyroxenites which may rise diapirically for long-term residence in continental lithosphere, and later contribute to the potassium (and geochemically-related elements) involved in some of the continental magmatism with geochemistry ascribed to mantle metasomatism.", "doi": "10.1007/BF01132067", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1982-12", "series_number": "4", "volume": "79", "issue": "4", "pages": "375-380" }, { "id": "authors:gyej1-q8h06", "collection": "authors", "collection_id": "gyej1-q8h06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-152332821", "type": "article", "title": "Synthetic Systems for Modeling Hybridization between Hydrous Siliceous Magmas and Peridotite in Subduction Zones", "author": [ { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The system KalSiO_4-Mg_2SiO_4-SiO_2-H_2O includes model representatives of (1) hydrous siliceous magma from subducted oceanic crust (the eutectic liquid in KalSi_3O_8-SiO_2-H_2O, and (2) the overlying mantle peridotite (forsterite+enstatite). Isothermal sections at 20 kbar to 30 kbar illustrate that hybridization causes precipitation of phlogopite, quartz, and enstatite, with little change in content of the liquid. The effects of CaO, Na_2O, and Al_2O_3 are examined by reviewing available data on phase relationships with additional components CaMgSi_2O_6, NaAlSiO_4, Al_2O_3 , and CaAl_2Si_2O_8. Addition of Na_2O and CaO changes the hybridization reactions by reducing the amount of phlogopite and by adding jadeitic clinopyroxene to the precipitation products, Addition of CaO and Al_2O_3 includes garnet among the precipitation products. The synthetic model systems appear to represent a good basis for extrapolation to the complex natural rock system. If minerals precipitating during hybridization are separated from melt by physical processes, discrete masses of phlogopite rocks, and phlogopite-garnet-websterites, may form a heterogeneous layer above subducted oceanic crust, which is transported deeper than the main, -fluxed sites of magma generation. Values of Mg/(Mg+Fe) of the hybridized layer are probably similar to that of the mantle.", "doi": "10.1086/628728", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1982-11", "series_number": "6", "volume": "90", "issue": "6", "pages": "734-741" }, { "id": "authors:m8xat-k8234", "collection": "authors", "collection_id": "m8xat-k8234", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-154731070", "type": "article", "title": "Barium phlogopite from the Jacupiranga carbonatite, Brazil", "author": [ { "family_name": "Gaspar", "given_name": "Jose C.", "clpid": "Gaspar-J-C" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phlogopites from the carbonatites intruded into the Jacupiranga alkalic complex have\nFeO/(FeO + MgO) within the restricted range 0.06 to 0.12, and BaO varying from 0.1 up to\n10.3 wt.%. Zoning with respect to BaO may be small, or it may exceed 3-4% BaO.\nPhlogopites and biotites from other carbonatites contain much less BaO, commonly below\n0.7%, but values of FeO/(FeO+ MgO) range up to 0.66. Phlogopites from mantle peridotite\nnodules and kimberlites have BaO contents less than 0.7%, with FeO/(FeO + MgO)\nvarying from low values for mantle phlogopites (corresponding to those of the Jacupiranga\ncarbonatites) up to values of at least 0.7 for kimberlite phlogopites. Leucite-bearing lavas\ncontain high Ba micas with FeO/(FeO + MeO) from 0.09-0.6, and BaO up to 7.3%.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1982-09", "series_number": "9-10", "volume": "67", "issue": "9-10", "pages": "997-1000" }, { "id": "authors:v1rb4-gvk79", "collection": "authors", "collection_id": "v1rb4-gvk79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-111229122", "type": "article", "title": "Subduction products according to experimental prediction", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Knowledge of the thermal structure and processes in subduction zones is so uncertain that our more extensive knowledge of source materials and phase relationships remains insufficient for prediction of magmatic products. The phase relationships do provide important constraints for testing geophysical and petrogenetic models, especially when considered along with geochemical constraints. Physical questions, such as the behavior of partially molten rocks, are intimately related to the compositions of magmas from source to eruption site. Tentative predictions and conclusions include: (1) Andesite is not a primary magma from oceanic crust. (2) It is unlikely that liquids from subducted oceanic crust yield andesites by fractionation, except by melting of amphibolite in an especially warm subducted crust. (3) It is more likely that hydrous siliceous magmas from the crust leak into the overlying mantle. (4) Andesite magmas can be generated in peridotite only under exceptional circumstances. (5) H2O-undersaturated basic magmas from peridotite modified by aqueous fluids or hydrous magma may yield andesite by fractionation. (6) Phlogopite peridotite could escape melting and yield alkalic magmas at deeper levels. (7) Andesite magmas could be produced in continental crust only by extreme heating through underplating of basalts or by mixing of basalt and rhyolite (derived from crust). Most of these conclusions need revision if convection in the asthenosphere wedge raises the temperature of the subducted slab to 1250\u00b0C at 100 km as proposed by Marsh (1979a); this demonstrates the dependence of experimental predictions on geophysical models.", "doi": "10.1130/0016-7606(1982)93<468:SPATEP>2.0.CO;2", "issn": "0016-7606", "publisher": "Geological Society of America", "publication": "Geological Society of America Bulletin", "publication_date": "1982-06", "series_number": "6", "volume": "93", "issue": "6", "pages": "468-476" }, { "id": "authors:v5vs2-yb994", "collection": "authors", "collection_id": "v5vs2-yb994", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-142656996", "type": "article", "title": "Phase relationships of I-type granite with H_2O to 35 kilobars: The Dinkey Lakes biotite-granite from the Sierra Nevada Batholith", "author": [ { "family_name": "Stern", "given_name": "Charles R.", "clpid": "Stern-C-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The Dinkey Lakes biotite-granite from the Sierra Nevada batholith was reacted (with varying percentages of H_2O in sealed platinum capsules) in a piston-cylinder apparatus between 10 and 35 kbar. The results were combined with the results from previously published experiments to provide comprehensive phase relationships for an I-type granite: a P-T diagram with excess H_2O; isobaric T-X_(H_2O) diagrams at 25, 30, and 35 kbar showing H_2O-undersaturated relations; the H_2O-undersaturated liquidus surface mapped with contours for constant H_2O contents and fields for near-liquidus minerals; and the solubility of H_2O in granite liquids to 35 kbar. Results and their implications show: (1) The solidus temperature decreases from 680\u00b0C at 2 kbar to 620\u00b0C at 10 kbar, then increases to 700\u00b0C at 35 kbar because of changes from less dense to more dense subsolidus mineral assemblages. (2) The melting interval with excess H_2O, which is only 35\u00b0C at 2 kbar, increases to 105\u00b0C at 10 kbar and 150\u00b0C at 35 kbar because the liquidus minimum in the complex rock system departs from granite composition with increasing pressure. (3) The solubility Of H_2O in granite liquid is 27 \u00b1 2.5 weight percent at 35 kbar and 850\u00b0C, indicating that a miscibility gap persists between H_2O-saturated silicate magmas and aqueous vapor phase, at least to pressures corresponding to 120-km depth in the mantle. Dissolution of alkali feldspar (20% of rock) in the subsolidus aqueous vapor phase indicates that deep-seated aqueous fluids are concentrated solutions. (4) Quartz and coesite are the liquidus minerals at mantle pressures for all H_2O contents, indicating that granites and rhyolites cannot be primary magmas from mantle peridotite or subducted oceanic gabbroic crust. (5) The liquidus surface at crustal pressures, with plagioclase and quartz as primary minerals, indicates that primary liquids of granite composition with moderate H_2O contents can be generated in the crust at reasonable temperatures; these liquids could rise to near surface levels without vesiculation. Granite liquid together with residual crustal minerals could constitute plutonic magmas of intermediate composition.", "doi": "10.1029/JB086iB11p10412", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research B", "publication_date": "1981-11-10", "series_number": "B11", "volume": "86", "issue": "B11", "pages": "10412-10422" }, { "id": "authors:vpcrn-mvt77", "collection": "authors", "collection_id": "vpcrn-mvt77", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-141147490", "type": "article", "title": "Phase relationships of S-type granite with H2_O to 35 kbar: Muscovite granite from Harney Peak, South Dakota", "author": [ { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Muscovite granite (13.8% muscovite, 4.8% normative corundum) was reacted, with varying percentages of H_2O, in cold-seal vessels at 2 kbar and in piston-cylinder apparatus between 10 and 35 kbar. The diagrams illustrating melting/crystallization relationships are: P-T sections with both excess H_2O and with no H_2O added (0.66% H_2O in rock); T-X_(H_2O) sections at 15 kbar and 25 kbar showing H_2O-undersaturated conditions; the H_2O-undersaturated surface for the crystallization of quartz/coesite (small amounts of aluminosilicate minerals persist to higher temperatures). Glass compositions measured by electron microprobe from samples with 5% H_2O at 15 kbar confirm that liquids are syenitic through at least 100\u00b0C above the solidus, as predicted from the effect of pressure on the Residua System. Results are explained successfully by phase relationships involving muscovite, quartz, and orthoclase in K_2O-Al_2O_3-SiO_2-H_2O, with reactions depicted in a P_(total)-P_(e_(H_2O))-T model, with special reference to the divariant surfaces in the region P_(e_(H_2O)) < P_(total). With reduced P_(e_(H_2O)) (or a_(H_2O)), produced either by small amounts of H_2O (and H_2O-undersaturation) or by CO_2 + H_2O mixtures, subsolidus dehydration reaction temperatures decrease, vapor-present solidus temperatures increase, and muscovite stability in presence of liquid increases. In general, muscovite, biotite, and amphibole can be precipitated from magmas containing only a few tenths per cent H_2O (although the H_2O-undersaturated liquids coexisting with crystals may contain 3% or more dissolved H_2O). This particular granite cannot be a primary magma from mantle or subducted oceanic crust. It is a possible product of partial fusion of pelitic rocks between about 20 km and 40 km depth given sufficient H2O, and xenocrystal muscovite or sillimanite from the source rocks. The phase relationships are consistent with the idea of S-type granites, but not sufficient to prove the origin of this rock. Additional tests require phase relationships of other associated granitic rocks, and details of geochemistry, geophysics, and field relationships.", "doi": "10.1029/JB086iB11p10515", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research B", "publication_date": "1981-11-10", "series_number": "B11", "volume": "86", "issue": "B11", "pages": "10515-10529" }, { "id": "authors:e279j-25r47", "collection": "authors", "collection_id": "e279j-25r47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-105726673", "type": "article", "title": "Phase relationships at 30 kbar for quartz eclogite composition in CaO-MgO-Al_2O_3-SiO_2-H_2O with implications for subduction zone magmas", "author": [ { "family_name": "Sekine", "given_name": "Toshimori", "clpid": "Sekine-Toshimori" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Baker", "given_name": "Don R.", "clpid": "Baker-D-R" } ], "abstract": "Synthetic starting material, corresponding to oceanic tholeiite (analysis wt.%: SiO_2, 52.5;\nAl_2O_3, 15.6; MgO, 14.6; CaO, 17.3), was run in sealed capsules at 30 kbar with 3.5% to 32.5%\nH_2O for comparison with the phase diagram previously reported for a natural gabbro-H_2O.\nThe subsolidus assemblage is zoisite-coesite-eclogite, with the solidus at 810\u00b0C. Coesite/\nquartz disappears just above the solidus, zoisite between 900\u00b0 and 950\u00b0C, eclogite + liquid\npersists through a wider temperature interval, and clinopyroxene + liquid exists below the\nliquidus. The liquidus is at 1110\u00b0C with excess H_2O, and 1360\u00b0C with 7.5% H_2O. Compositions\nof glass, clinopyroxene, garnet and zoisite were measured by electron microprobe for\nruns with 7.5% H_2O. Glass analyses could not be obtained for runs below 1050\u00b0C. Glass analyses\nfor runs at 1100\u00b0C and 1200\u00b0C included values that could not represent original liquid\ncompositions, suggesting that the liquid composition changes during the quench, for reasons\nnot fully understood. Equilibrium compositions of liquids were calculated from estimated\nmodes and mass balance. The equilibrium liquid paths for both model and natural-rock compositions\ndiverge from the average chemical variation of the calc-alkaline rock series, with divergence\ngreatest for about 20-25% liquid where SiO_2 content corresponds to that of andesite.\nPartial melting of quartz eclogite in subducted oceanic crust at 100 km depth would produce\nliquids with Ca/(Mg+Fe) higher than andesites. Therefore, andesite is not a primary magma\nfrom subducted oceanic crust deeper than amphibole breakdown.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1981-09", "series_number": "9-10", "volume": "66", "issue": "9-10", "pages": "938-950" }, { "id": "authors:prwcm-d6c60", "collection": "authors", "collection_id": "prwcm-d6c60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-151053933", "type": "article", "title": "Subsolidus and melting relations for the join CaCO_3-MgCO_3 at 10 kbar", "author": [ { "family_name": "Byrnes", "given_name": "Alan P.", "clpid": "Byrnes-A-P" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mixtures of pure dry CaCO_3 and MgCO_3 were reacted at 10 kbar in a piston-cylinder apparatus. Solidus and liquidus boundaries were delineated by interpretation of quenched textures. X-ray determined compositions of quenched carbonates are not a reliable guide to the phase relations. The binary melting loop for CaCO_3-MgCO_3 extends from CaCO_3 at 1460\u00b0C through a liquidus minimum near 30 wt% MgCO_3 and 1075\u00b0C, and it is terminated at the incongruent melting reaction for dolomite solid solution at 1125\u00b0 C (liquid with 32 wt% MgCO_3) Magnesite solid solution dissociates at 1090\u00b0C to produce dolomite + periclase + CO_2, truncating the dolomite-magnesite solvus. The 10 kb liquidus minimum at 1075\u00b0C and 30 wt% MgCO_3 occurs at lower temperature and higher Ca/Mg ratio than the 27 kbar liquidus minimum at 1290\u00b0C and 38 wt% MgCO_3. This relationship suggests that the first liquid produced by melting of a carbonate-bearing peridotite has increasing Mg/Ca ratio with increasing pressure. These phase relations provide part of the framework required to trace paths of crystallization of kimberlite and carbonatite magmas.", "doi": "10.1016/0016-7037(81)90242-8", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1981-03", "series_number": "3", "volume": "45", "issue": "3", "pages": "321-328" }, { "id": "authors:5grkh-amx40", "collection": "authors", "collection_id": "5grkh-amx40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-090337231", "type": "article", "title": "Plate tectonics and magma genesis", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The framework of plate tectonics, with active boundaries and stable plates, is the best yet devised for explaining the different types and styles of magmatic activity. The dynamic mechanisms of plate tectonics transport rock masses across fusion boundaries in three distinct types of environment and source material, associated with plate boundaries. These are divergent boundaries where mantle peridotite is transported upwards, melting to yield basalt, convergent boundaries where oceanic crust is transported downwards, melting to yield magma of intermediate SiO_2 content, and ocean-continent convergent boundaries where the lower part of continental margins are melted to yield rhyolite magma. Hot spots beneath plates, possibly generated by mantle plumes, yield basaltic magma from mantle and rhyolite magma from overlying continental crust. Subducted H_2O is involved in the generation of andesites and batholiths, and CO_2 from uncertain sources is an influential component for the generation of kimberlite and other low SiO_2, high alkali magmas below continental plates. The chemical differentiation of the earth is accomplished through magmatic processes which are a direct manifestation of convection within the mantle. Igneous petrology is now a study of processes and products firmly rooted in geophysics, and calibrated by laboratory experiments at high pressures and temperatures.", "doi": "10.1007/BF01764318", "issn": "0016-7835", "publisher": "Springer Verlag", "publication": "Geologische Rundschau", "publication_date": "1981-02", "series_number": "1", "volume": "70", "issue": "1", "pages": "128-153" }, { "id": "authors:8ksey-e8n04", "collection": "authors", "collection_id": "8ksey-e8n04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160308-103415109", "type": "article", "title": "Experimental petrology of subduction, andesites, and batholiths", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "[no abstract]", "issn": "0371-7208", "publisher": "Geological Society of South Africa", "publication": "Transactions of the Geological Society of South Africa", "publication_date": "1981", "volume": "84", "pages": "281-291" }, { "id": "authors:f8pf7-5hr49", "collection": "authors", "collection_id": "f8pf7-5hr49", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-145624253", "type": "article", "title": "The origin of kimberlite", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "A new diapiric model for kimberlite genesis takes into account recent interpretations of peridotite-CO_2-H_2O melting relationships. A minor thermal perturbation at depth might trigger release of reduced vapors with major components C-H-O. Where these volatile components cross the estimated solidus boundary near 260 km, partial melting occurs, the density inversion causes diapiric uprise along adiabats, and the partially melted diapirs begin to crystallize at 100 to 80-km depth, where they reach a temperature maximum (thermal barrier) on the solidus. The released vapor enhances the prospects for crack propagation through overlying lithosphere in tension, and this could produce an initial channel to the surface. Magma separation could then occur from progressively greater depths, releasing CO_2-under-saturated kimberlitic magma for independent uprise through the established conduit, quite unaffected by the thermal barrier on the solidus of peridotite-CO_2-H_2O. Cooler diapirs would cross the solidus at somewhat greater depth, solidifying to phlogopite-dolomite-peridotite with the release of aqueous solutions. These solutions are likely candidates for the mantle metasomatism commonly considered to be a precursor for the generation of kimberlites and other alkalic magmas. According to this model the metasomatism is a consequence of kimberlite magmatism rather than its precursory cause.", "doi": "10.1029/JB085iB12p06902", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research B", "publication_date": "1980-12-10", "series_number": "B12", "volume": "85", "issue": "B12", "pages": "6902-6910" }, { "id": "authors:jbpgc-9er34", "collection": "authors", "collection_id": "jbpgc-9er34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141105-143853050", "type": "article", "title": "Studies in synthetic carbonatite systems: Solidus relationships for CaO-MgO-CO_2-H_2O to 40 kbar and CaO-MgO-SiO_2-CO_2-H_2O to 10 kbar", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The system CaO-MgO-SiO_2-CO_2-H_2O is an important model for many igneous and metamorphic processes, including the generation and differentiation of carbonatite and associated silicate magmas. We have experimentally established the vapor-saturated solidus for the system CaO-MgO-CO_2-H_2O from 595\u00b0C/1 kbar to <500\u00b0C/40 kbar, about 25\u00b0C lower than the corresponding temperatures for the CaO-CO_2-H_2O system. Brucite replaces periclase on the vapor-saturated solidus at about 750 bars pressure, remaining as the stable phase to pressures of at least 40 kbar; no dolomite or magnesite was encountered. At a pressure between 35 and 40 kbar, the assemblage portlandite + brucite + aragonite + vapor changes to one containing phase W, a previously unreported Ca-Mg carbonate. At 20 kbar, the vapor-saturated liquid contains at least 24 wt % H_2O. The vapor-saturated solidus for the system CaO-MgO-SiO_2-CO_2-H_2O ranges from 613\u00b0C/1 kbar to 565\u00b0C/10 kbar, experimentally indistinguishable from that for CaO-MgO-CO_2-H_2O, about 10\u00b0C lower than that for CaO-CO_2-H_2O, and about 25\u00b0C lower than that for CaO-SiO_2-CO_2-H_2O. In the quinary system, monticellite is replaced by dellaite and an unidentified silicate on the vapor-saturated solidus above 4.1 kbar. MgO-poor liquids are similar in composition to the magma from which the Magnet Cove calcite carbonatite crystallized. More magnesian magmas would produce dolomite at moderate depths, such as at Aln\u00f6 Island.", "doi": "10.1029/JB085iB12p06937", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research B", "publication_date": "1980-12-10", "series_number": "B12", "volume": "85", "issue": "B12", "pages": "6937-6943" }, { "id": "authors:jqqby-jk085", "collection": "authors", "collection_id": "jqqby-jk085", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-085241942", "type": "article", "title": "Phase relations and their petrological implications in the system MgO-SiO_2-H_2O-CO_2 at pressures up to 100 kbar", "author": [ { "family_name": "Ellis", "given_name": "David E.", "clpid": "Ellis-D-E" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "A comprehensive model has been developed for phase relations in the system MgO-SiO_2-H_2O-CO_2 on the basis of Schreinemakers' rules and subsolidus thermodynamic data. The assemblage\nforsterite plus enstatite can melt in the presence of vapor of any H_2O/CO_2 ratio at\nlow pressures, in the presence of vapor whose H_2O/CO_2 ratio is buffered by magnesite at intermediate\npressures, and at a vapor-absent eutectic at high pressures. Forsterite and H_2O-CO_2 vapor cannot coexist at pressures greater than 90 kbar. A thermal maximum is postulated\nto exist on the reaction Fo + En + V \u2192 L at pressures greater than 35 kbar. Thermal\nmaxima on vapor-present melting reactions may be responsible for the eruption of kimberlitic\nmagma from the upper mantle.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1980-05", "series_number": "5-6", "volume": "65", "issue": "5-6", "pages": "540-556" }, { "id": "authors:qn33x-ak356", "collection": "authors", "collection_id": "qn33x-ak356", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-150341881", "type": "article", "title": "Subsolidus and liquidus phase relationships in the system CaO-SiO_2-CO_2 to 30 kbar with geological applications", "author": [ { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Nehru", "given_name": "C. E.", "clpid": "Nehru-C-E" } ], "abstract": "Mixtures of crystalline CaCO_3, Ca_2SiO_4, CaSiO_3, quartz, and spurrite were reacted between\n7 and 27 kbar. The results, combined with other published data, provide a PT projection\nfor the system CaO-SiO_2-CO_2 from 1 bar to 30 kbar, and a series of isobaric liquidus\ndiagrams giving the changes in composition of eutectic and peritectic liquids in the univariant\nreactions as a function of pressure. The assemblage calcite + quartz dissociates producing\nwollastonite + CO_2 at pressures below an invariant point at 18.5 kbar, 1,325\u00b0C; at this point,\nthe univariant dissociation reaction meets the fusion curve for wollastonite + CO_2 = quartz +\nliquid; at higher pressures, calcite + quartz melts incongruently to liquid + CO_2, and there is\nin addition a eutectic reaction between calcite, wollastonite, and quartz. The thermal barrier\non the liquidus associated with the congruent melting of lamite in the system CaO-SiO_2 is\neliminated by solution of a few percent CO_2 at pressures greater than about 1 kbar; the CO_2\ncauses expansion of the liquidus fields for calcite and wollastonite until they meet and exclude\nboth spurrite and lamite from the CO_2-saturated liquidus field boundary. The liquidus\ndiagrams show limiting conditions for coprecipitation of calcite and wollastonite in carbonatite\nmagmas. Liquids produced by partial melting of siliceous limestones (\u00b1wollastonite) at\npressures above about 15 kbar have compositions near 50% CaCO_3, 50% CaSiO_3. There is a\ngood prospect that some subducted pelagic limestone might escape dissociation and melting\nand be carried to considerable depths for long-term storage of carbon in the mantle either as\naragonite (reacting to dolomite or magnesite), or as diamond if the carbonate is reduced.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1980-03", "series_number": "3-4", "volume": "65", "issue": "3-4", "pages": "285-301" }, { "id": "authors:ze85f-h6083", "collection": "authors", "collection_id": "ze85f-h6083", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151106-120237562", "type": "article", "title": "James B. Macelwane Award: Citation and Acceptance of Robert Keith O'Nions", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "O'Nions", "given_name": "R. K.", "clpid": "O'Nions-R-K" } ], "abstract": "I have the pleasure to introduce Robert Keith O'Nions, a young man of 34, for the Macelwane Award, not because I have had anything to do with his education and research, but because I was a member of the committee this year, and we both originate from the same country. Keith O'Nions earned his B.Sc. from the University of Nottingham in 1966, traveled to Alberta for a Ph.D. in 1969, became a Postdoctoral Fellow in Oslo during 1970, joined the faculty at Oxford from 1971\u20131975, and moved to his present home at Columbia University in 1975.\n\nWhen the time came to find a citationist [sic] for him it turned out that his colleagues at Lamont-Doherty, who were the obvious choices, were all at sea\u2014and I admit that this is how I feel when I read some of Keith's papers. In a sense, this makes me well-suited for this introduction, because I cannot spend time explaining his research to you. Instead, I will read to you a couple of paragraphs from his nomination for the award, written by an anonymous friend.", "doi": "10.1029/EO060i031p00549-01", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1979-07-31", "series_number": "31", "volume": "60", "issue": "31", "pages": "549-550" }, { "id": "authors:h9bnx-jmb33", "collection": "authors", "collection_id": "h9bnx-jmb33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-102641552", "type": "article", "title": "Magmas and volatile components", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The trivial quantities of CO_2 and H_2O (or reduced combination of C-H-O-S) in the upper\nmantle have little effect on the abundant basalts, but H_2O influences magmas generated in\nperidotite overlying subducted, hydrated oceanic crust, and CO_2 causes the generation of\nalkalic subsilicic magmas from peridotite beneath continental shields. PT sections through the\n(partly schematic) phase diagram for peridotite-CO_2-H_2O with low (CO_2 + H_2O) and selected\nCO_2/H_2O, compared with isotherms, illustrate the petrological structure of the upper mantle\nfor different tectonic environments. If vapor is present, the cooler the geotherm, the higher is\nH_2O/CO_2: only in regions of upwelling can CO_2-rich vapor exist. The solidus surface for\nperidotite-CO_2-H_2O (P, T, X^V) has been mapped with tentative boundaries marking changes\nin normative compositions of near-solidus magmas. The restricted area for quartz-normative\nmagmas suggests that if these are to be generated from mantle in subduction zones, there must\nbe active asthenospheric convection carrying hot mantle to shallow levels above dehydration\nfronts in subducted oceanic crust. Changes in the relative positions of dehydration fronts and\nsolidus boundaries for warm and cool subduction models are illustrated in new diagrams,\nunencumbered by the need for precise temperatures and depths. Tests for processes require\nknowledge of the phase relationships in the system basalt-andesite-dacite-rhyolite-H_2O from\nmagma sources at depth to the surface. Data from scattered sources have been synthesized in a\nPTX(SiO_2)X(H_2O) framework to 35 kbar, and illustrated in sections and projections, including\nliquidus surfaces for the rock series to 35 kbar, dry, with 5 percent H_2O, and with excess H_2O\n(saturated). The volatile components become prominent in residual magmas: pegmatites from\ngranitic magmas are enriched in H_2O, and carbonatites from alkalic magmas are extraordinarily\nenriched in CO_2. The behavior of another volatile component is illustrated by experimental\ndata in NaAlSi_3O_8-H_2O-HF at 2.75 kbar. The vapor-saturated liquidus field boundary\nextends from 808\u00b0C-8.5 percent H_2O to 777\u00b0C-(9.2 percent H_2O + 1.0 percent HF), and\nthree-phase boundaries demonstrat1i strong partition of HF into liquid compared with vapor.\nDetails remain uncertain for the sources of volatile components, in mantle reservoirs or\nrecycled through subduction, and of oxygen fugacity and temperature variation with depth in\ndifferent tectonic environments.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1979-05", "series_number": "5-6", "volume": "64", "issue": "5-6", "pages": "469-500" }, { "id": "authors:t03b8-f9h94", "collection": "authors", "collection_id": "t03b8-f9h94", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-074923418", "type": "article", "title": "The join grossularite-pyrope at 30 kb and its petrological significance", "author": [ { "family_name": "Maal\u00f8e", "given_name": "Sven", "clpid": "Maal\u00f8e-S" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The pseudobinary join grossularite-pyrope was investigated at 30 kb\nnominal pressure at temperatures between 1300\u00b0 and 1725\u00b0C, using piston-cylinder\napparatus. Grossularite melts incongruently to gehlenite + liquid at 1545\u00b0C, and pyrope\nmelts incongruently to spinel+ liquid at 1705\u00b0C. Aluminous diopside forms a congruent\ncompound within the join and melts at 1595\u00b0C. The join has two binary eutectics, where\ndiopside is in equilibrium with either grossularite-rich garnet or pyrope-rich garnet.\nAll eutectic compositions are on the join, and the join is a thermal barrier at 30 kb within\nthe system CaSiO_3-MgSiO_3-Al_2O_3. The phase relations suggest that nephelinites might\nhave formed at pressures near or above 30 kb, and that nephelinites fractionate toward a\nthermal minimum on the garnet + diopside liquid surface, with eclogitic mineralogy.", "doi": "10.2475/ajs.279.3.288", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1979-03", "series_number": "3", "volume": "279", "issue": "3", "pages": "288-301" }, { "id": "authors:k70h2-fn917", "collection": "authors", "collection_id": "k70h2-fn917", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-101947402", "type": "article", "title": "Liquidus relationships in the system CaCO_3-Ca(OH)_2-CaS and the solubility of sulfur in carbonatite magmas", "author": [ { "family_name": "Helz", "given_name": "George R.", "clpid": "Helz-G-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "CaCO_3-Ca(OH)_2-CaS serves as a model system for sulfide solubility in carbonatite magmas. Experiments at 1 kbar delineate fields for primary crystallization of CaCO_3, Ca(OH)_2 and CaS. The three fields meet at a ternary eutectic at 652\u00b0C with liquid composition (wt%): CaCO_3 = 46.1%, Ca(OH)_2 = 51.9%, CaS = 2.0%. Two crystallization sequences are possible for liquids that precipitate calcite, depending upon whether the liquid is on the low-CaS side, or the high-CaS side of the line connecting CaCO3 to the eutectic liquid. Low-CaS liquids precipitate no sulfide until the eutectic temperature is reached leading to sulfide enrichment. The higher-CaS liquids precipitate some sulfide above the eutectic temperature, but the sulfide content of the melt is not greatly depleted as the eutectic temperature is approached. Theoretical considerations indicate that sulfide solubility in carbonate melts will be directly proportional to \u0192S212 and inversely proportional to \u0192O212; it also is likely to be directly proportional to melt basicity, defined here by a CO32\u2212\u0192CO2. A strong similarity exists in the processes which control sulfide solubility in carbonate and in silicate melts. By analogy with silicates, ferrous iron, which was absent in our experiments, may also exert an important influence on sulfide solubility in natural carbonatite magmas.", "doi": "10.1016/0016-7037(79)90244-8", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1979-02", "series_number": "2", "volume": "43", "issue": "2", "pages": "259-265" }, { "id": "authors:tq7er-tp813", "collection": "authors", "collection_id": "tq7er-tp813", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-140025194", "type": "article", "title": "Carbonation, hydration, and melting relations in the system MgO-H_2O-CO_2 at pressures up to 100 kbar", "author": [ { "family_name": "Ellis", "given_name": "David E.", "clpid": "Ellis-D-E" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "A model has been derived for the subsolidus and melting relationships in the system MgO-H_2O-CO_2 for pressures up to 100 kbar. Using both low- and high-pressure experimental data,\nthe \u0394H\u00b0 and \u0394S\u00b0 for the subsolidus reactions Mg(OH)_2 \u2192 MgO + H_2O, MgCO_3 \u2192 MgO +\nCO_2, and MgCO_3 + H_2O \u2192 Mg(OH)_2 + CO_2 are estimated to be respectively: \u0394H\u00b0 = 18400\ncal/mol and \u0394S\u00b0 = 33.16 cal/ \u00b0 mol, \u0394H\u00b0 = 20140 cal/mol and \u0394S\u00b0 = 34.87 cal/\u00b0 mol and \u0394H\u00b0\n= 1740 cal/mol and \u0394S\u00b0 = 1.71 cal/\u00b0 mol. In the presence of MgCO_3, vapor is buffered to high\nvalues of H_2O/CO_2 except for a narrow pressure interval just above the reaction MgCO_3 \u2192\nMgO + CO_2. As pressure is increased the vapor coexisting with an MgCO_3-bearing assemblage\nbecomes richer in H_2O. MgCO_3 first melts at an invariant point located at 23 kbar and\n1550\u00b0C. Mg(OH)_2 melts at an invariant point estimated to be near 58 kbar and 1310\u00b0C.\nMg(OH)_2 + MgCO_3 + vapor melt together at a eutectic at pressures greater than or equal to\nthat of an invariant point located near 46 kbar and 1210\u00b0C. The composition of the eutectic\nliquid on the join Mg(OH)_2-MgCO_3 is estimated to be 73 mole percent Mg(OH)_2 plus 27 mole\npercent MgCO_3. The system MgO-H_2O-CO_2 provides the thermodynamic basis for estimating\nthe distribution of H_2O and CO_2 between coexisting liquids and vapors in the presence of\nhydrates and carbonates, and is an essential first step leading to the interpretation of similar\nphase relationships in the model mantle system CaO-MgO-Al_2O_3-SiO_2-H_2O-CO_2.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1979-01", "series_number": "1-2", "volume": "64", "issue": "1-2", "pages": "32-40" }, { "id": "authors:3yywd-hjq38", "collection": "authors", "collection_id": "3yywd-hjq38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-133224481", "type": "article", "title": "Hydration and melting reactions in the system MgO-SiO_2-H_2O at pressures up to 100 kbar", "author": [ { "family_name": "Ellis", "given_name": "David E.", "clpid": "Ellis-D-E" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The proposed model for the system MgO-SiO_2-H_2O ties subsolidus and melting reactions\ninto an internally-consistent P-T net. None of the hydrous magnesium silicates considered is\nstable at the temperature of the solidus for forsterite + enstatite + H_2O; however, brucite is\nstable at solidus temperatures and at pressures greater than 50 kbar. In the presence of H_2O\nenstatite melts incongruently to forsterite plus a silica-saturated liquid at pressures up to 90\nkbar. At 90 kbar the hydration reaction Fo + H_2O \u2192 En + Br intersects the solidus, and at\nhigher pressures forsterite and H_2O do not coexist. The melting of forsterite + enstatite in the\npresence of a small amount of H_2O is vapor-present at pressures up to 90 kbar and generates a\nvapor-saturated, silica-saturated liquid. At higher pressures melting of the same bulk composition\ngenerates a silica-saturated, vapor-undersaturated liquid.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1979-01", "series_number": "1-2", "volume": "64", "issue": "1-2", "pages": "41-48" }, { "id": "authors:3w9dt-fnb87", "collection": "authors", "collection_id": "3w9dt-fnb87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-080231674", "type": "article", "title": "Water and magma generation at subduction zones", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The basaltic ocean crust, metasomatized and metamorphosed during and after generation at the ocean ridge, contains H_2O stored in minerals and pore fluid. Phase equilibrium data establish the conditions for dehydration, and the conditions for melting of amphibole-gabbro or amphibole-quartz-eclogite, or for quartz-eclogite or mantle peridotite if aqueous fluids are available. But there is no concensus about the temperature distribution through the subducted crust, or within the overlying mantle wedge. Therefore, a variety of magmatic models can be derived from the experimental data. According to some calculations, endothermic dehydration reactions in the depth interval 75\u2013125 km cool the oceanic crust to such an extent that it cannot be a major source of magmas; instead, concentrated aqueous fluids released from the crust generate magmas in the overlying peridotite. However, according to most existing thermal models, if temperatures in ocean crust are cool enough to prohibit melting of amphibolite, then temperatures in the mantle above the main sources of expelled fluids are too low for hydrous melting. The ocean crust appears to be effectively dehydrated by 100\u2013125 km depth. Dense hydrous magnesian silicates are not likely candidates for deeper H_2O transport. The extent to which H_2O can be fixed in metasomatic phlogopite in crust or mantle is a significant but undetermined factor. Experimental data on minerals and liquid compositions do not support the concept of primary magmas for andesites and associated lavas from mantle or subducted crust. Complex, multi-stage processes appear to be more likely, which is consistent with recent interpretations of geochemical data.", "doi": "10.1007/BF02597371", "issn": "0366-483X", "publisher": "Springer", "publication": "Bulletin Volcanologique", "publication_date": "1978-12", "series_number": "4", "volume": "41", "issue": "4", "pages": "360-377" }, { "id": "authors:mxkrf-fmz47", "collection": "authors", "collection_id": "mxkrf-fmz47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-080749836", "type": "article", "title": "Peridotite-CO_2-H_2O and the low-velocity zone", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The properties of the seismic low-velocity zone are consistent with incipient melting of mantle peridotite. Vapor-absent melting of amphibole-peridotite has been used to model the low-velocity zone, but evidence that CO_2 exists in the upper mantle indicates that peridotite-CO_2-H_2O would be a better model. The divariant solidus surface for peridodite-CO_2-H_2O is traversed by a series of univariant lines marking the intersections of divariant subsolidus reactions involving dolomite or magnesite, amphibole, or phlogopite (other hydrous minerals are neglected in this treatment), or combinations of these. The vapor phase compositions are buffered to specific values, which limits the range of vapor compositions that can coexist with peridotite at various pressures. Below about 30 kbar, the vapor phase is buffered by the melting of amphibole-peridotite, with composition ranging from H_2O to high CO_2/H_2O. Above about 25 kbar, the vapor phase is buffered by the melting of dolomite-peridotite, with composition ranging from CO_2 to high H_2O/CO_2 at pressures above 30 kbar. The buffered curve for phlogopite-peridotite intersects the dolomite-peridotite curve, generating another line for phlogopite-dolomite-peridotite; the strong buffering capacity of dolomite forces the vapor on this line to high H_2O/CO_2. Near the buffered curve for the solidus of partly carbonated peridotite there is a temperature maximum on the peridotite-vapor solidus surface. On the CO_2 side of the maximum, above 26 kbar, CO_2/H_2O is greater in liquid than in vapor; on the H_2O side of this maximum, and at all pressures below 26 kbar, CO_2/H_2O is greater in vapor than in liquid. The suboccanic low-velocity zone is caused by incipient melting of amphibole-peridotite in the presence of vapor with high CO_2/H_2O, with generation of forsterite-normative liquid. The subcontinental low-velocity zone, where present, is probably caused by incipient melting of dolomite-peridotite, or phlogopite-dolomite-peridotite, either with H_2O-rich vapor or without vapor, with the generation of CO_2-rich, alkalic, SiO_2-poor liquid (larnite-normative) that in extreme conditions may be carbonatitic.", "doi": "10.1007/BF02597393", "issn": "0366-483X", "publisher": "Springer", "publication": "Bulletin Volcanologique", "publication_date": "1978-12", "series_number": "4", "volume": "41", "issue": "4", "pages": "670-683" }, { "id": "authors:rhekc-8c738", "collection": "authors", "collection_id": "rhekc-8c738", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-085559111", "type": "article", "title": "Mantle Fluid Compositions Buffered in Peridotite-CO_2-H_2O by Carbonates, Amphibole, and Phlogopite", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental and theoretical data from systems peridotite- CO_2-H_2O and CaO-MgO-SiO_2-CO_2-H_2O are combined, and extrapolated to 70 Kb for construction of partly schematic diagrams for subsolidus and near-solidus phase relationships of peridotite containing CO_2 and H_2O. The divariant solidus surface for peridotite-vapor in the presence of CO_2+H_2O is traversed by a series of univariant lines marking the intersections of divariant subsolidus carbonation/decarbonation and hydration/dehydration reactions occurring in the presence of CO_2-H_2O vapors. For H_2O-CO_2 contents up to certain limits, the vapor phase composition along these lines is buffered by carbonates or hydrous minerals, and liquid compositions are similarly defined. The approximate positions have been estimated for vapor-buffer lines on the solidus involving dolomite, amphibole, amphibole-dolomite, phlogopite, and phlogopite-dolomite. The buffering capacity of carbonate is far greater than that of hydrous minerals. Considering normal mantle peridotite with olivine, orthopyroxene and clinopyroxene, the maximum amounts of phlogopite and amphibole are produced by about 0.02% H_2O and 0.4% H_2O, respectively. About 5% CO_2 is required to produce the maximum amount of dolomite without complete reaction of clinopyroxene and loss of peridotite mineralogy. The buffered curve for partly carbonated peridotite extends to lower temperatures and higher pressures from an invariant point near 26 Kb and 1,200\u00b0C Near this line there is a temperature-maximum on the peridotite-vapor solidus. On the high-pressure side of this maximum, CO_2/H_2O is greater in liquid than in vapor; on the low-pressure side of the maximum (including all pressures below 26 Kb), CO_2/H_2O is greater in vapor than in liquid. Because of this maximum, near-solidus magmas rising along an adiabat would evolve dissolved volatile components in the depth range 100-80 km; this could contribute to explosive eruptions. At pressures greater than 30 Kb, mantle peridotite with H_2O and CO_2 melts along curves with vapor buffered to high CO_2/H_2O by dolomite (magnesite at higher pressures) or dolomite + phlogopite, or a vapor-absent curve for dolomite-phlogopite-peridotite, producing low-SiO_2 magmas. The relationships among carbon, carbonate, and oxygen fugacity are important for determination of magma compositions.", "doi": "10.1086/649737", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1978-11", "series_number": "6", "volume": "86", "issue": "6", "pages": "687-713" }, { "id": "authors:qpcyt-q7f22", "collection": "authors", "collection_id": "qpcyt-q7f22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-094415345", "type": "article", "title": "Phase compositions through crystallization intervals in basalt-andesite-H_2O at 30 kbar with implications for subduction zone magmas", "author": [ { "family_name": "Stern", "given_name": "Charles R.", "clpid": "Stern-C-R" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The melting relationships of a gabbro (olivine tholeiite, quartz eclogite composition) and\ntonalite (andesite composition) with varying amounts of H_2O added were determined at 30\nkbar pressure using piston-cylinder apparatus. With 5 percent H_2O, clinopyroxene and garnet\nare the liquid us minerals for the basalt, and they occur together throughout the crystallization\ninterval from 1260\u00b0 to 760\u00b0C. With 5 percent H_2O, garnet is the liquidus phase for andesite at\n1200\u00b0C and it crystallizes alone through 100\u00b0C; garnet and clinopyroxene occur together\nthrough the rest of the crystallization interval from 1100\u00b0 to 740\u00b0C. Compositions of garnets,\nclinopyroxenes, and glasses were measured with electron microprobe at the following temperatures:\ntonalite, 1175\u00b0 (Ga,Gl), 1100\u00b0 (Ga,Cpx,Gl), 1000\u00b0 (Ga,Cpx,Gl), 900\u00b0 (Cpx,Gl);\ngabbro, 1200\u00b0 (Ga,Cpx), 1100\u00b0C (Ga,Cpx). Published data by T. H. Green and Ringwood on\nhydrous and anhydrous calc-alkaline rock compositions, combined with these new data,\ndefine compositional trends for minerals through the upper parts of crystallization intervals.\nFrom these trends and thermodynamic constraints for mineral pairs, the compositions of\nminerals through the complete crystallization intervals were calculated. Using calculated\nmineral compositions and estimated mineral proportions, the compositions of equilibrium\nliquid paths were calculated through the crystallization intervals of hydrous and anhydrous\nbasalts, basaltic andesite, and andesite. Compositions of quenched liquids in the crystallization\ninterval of andesite with 5 percent H_2O measured with the electron microprobe agree well\nwith calculated compositions, supporting the validity of the calculated liquid paths. Equilibrium\nliquid paths for basalts and andesites at 30 kbar diverge from the average chemical\nvariation trend of typical calc-alkaline rocks (basalt-andesite-dacite-rhyolite). With decreasing\ntemperature and increasing SiO_2 content, the liquid paths increase in Ca/(Mg+ Fe)\ncompared with the average trend, more so for hydrous compositions than for anhydrous.\nWith equilibrium partial fusion of quartz eclogite, the first liquids are richer in Si02 than\naverage andesites, significantly so if H_2O is present. Liquids with SiO_2 content corresponding\nto andesites occupy no distinctive position such as a thermal valley; they are situated within a\ncontinuous sequence of liquid compositions. Partial melting of subducted ocean crust at 100\nkm depth produces liquids with a range of intermediate SiO_2 contents, but these must be\nmodified by fractionation at shallower depths if they are to reach the surface with chemistry\ncorresponding to average calc-alkaline lavas.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1978-07", "series_number": "7-8", "volume": "63", "issue": "7-8", "pages": "641-663" }, { "id": "authors:c5mj6-6a612", "collection": "authors", "collection_id": "c5mj6-6a612", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141110-164300664", "type": "article", "title": "The effect of H_2O and CO_2 on planetary mantles", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The solidus for peridotite-H_2O-CO_2 is a divariant surface traversed by univariant lines that locate the intersections of subsolidus divariant surfaces for carbonation or hydration reactions occurring in the presence of H_2O-CO_2 mixtures. Vapor phase compositions are normally buffered to these lines; the buffering capacity of carbonates is much greater than that of amphibole and phlogopite. Near the buffered curve for the solidus of partly carbonated peridotite, extending to higher pressures and lower temperatures from an invariant point near 26 kb-1200\u00b0C, there is a temperature maximum on the peridotite-vapor solidus. On the CO_2 side of the maximum, above 26 kb, CO_2/H_2O is greater in liquid than in vapor, and liquids are SiO_2-poor; on the H_2O side of this maximum (including all pressures below 26 kb), H_2O/CO_2 is greater in liquid than in vapor, and liquids change from forsterite-normative to quartz-normative with increasing H_2O/CO_2 in vapor. Even traces of H_2O and CO_2, in minerals or vapor, lower mantle solidus temperatures through hundreds of degrees compared with the volatile-free solidus.", "doi": "10.1029/GL005i006p00440", "issn": "0094-8276", "publisher": "American Geophysical Union", "publication": "Geophysical Research Letters", "publication_date": "1978-06", "series_number": "6", "volume": "5", "issue": "6", "pages": "440-442" }, { "id": "authors:vwp2m-gg988", "collection": "authors", "collection_id": "vwp2m-gg988", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-153621769", "type": "article", "title": "Experimental Petrology at High Pressures and Temperatures", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "In 1969, when it was first suggested that a Subcommission on Experimental Petrology at High Pressures\nand Temperatures be established, the reaction from the IUGS Petrology Commission was favourable. The\nSubcommission, with six members and Professor Werner Schreyer as Chairman, became a Commission\n(CEPHT) in 1972. Peter Wyllie, current Chairman of this Commission, describes the evolution of\nexperimental petrology, its application to geophysical, petrological and geological processes, as well as what\nlies ahead in future exploration of this \"research frontier\".", "issn": "0705-3797", "publisher": "International Union of Geological Sciences", "publication": "Episodes", "publication_date": "1978-03", "series_number": "1", "volume": "1", "issue": "1", "pages": "6-10" }, { "id": "authors:gh562-q2f54", "collection": "authors", "collection_id": "gh562-q2f54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-102524697", "type": "article", "title": "Crustal anatexis: An experimental review", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Review of experimental studies in synthetic systems An\u2014Ab\u2014Or\u2014Qz\u2014H_2O and K_2O\u2014A\u2113_2O_3\u2014SiO_2\u2014H_2O illustrates the dominance of feldspar\u2014quartz assemblages in crustal anatectic processes, and the role of hydrous minerals such as muscovite. H_2O-undersaturated liquids can exist with quartz\u2014feldspar assemblages through hundreds of degrees with little change in composition in terms of anhydrous components. Review of the phase relationships in the rock series gabbro\u2014tonalite\u2014granodiorite\u2014granite\u2014H_2O to 15 kbar is used as a basis for interpreting anatexis of deep crustal rocks, including metamorphosed grey wackes and pelitic rocks. For individual rocks, diagrams include PT projections with excess H_2O, with hydrous minerals but no excess H_2O, of H_2O-undersaturated liquidus surfaces, and isobaric T-X_(H_2O) sections. For the rock series, 10 kbar diagrams show the melting interval with excess H_2O, the H_2O-undersaturated liquidus surface, and the melting interval with 2% H_2O. The normal product of regional metamorphism is H_2O-undersaturated granitic liquid; H_2O-saturated liquids exist only through narrow temperature intervals. Liquids of granite composition trend towards granodiorite with increasing temperature or pressure, but compositions do not reach tonalite unless metamorphic temperatures approach 1100\u00b0C. Tonalite plutons represent mushes of granitic liquid with refractory residual crystals, or recrystallized residual masses from which the granitic liquid escaped. Some tonalite plutons may be derived from magmas with source in subducted ocean crust or mantle.", "doi": "10.1016/0040-1951(77)90005-1", "issn": "0040-1951", "publisher": "Elsevier", "publication": "Tectonophysics", "publication_date": "1977-11-15", "series_number": "1-2", "volume": "43", "issue": "1-2", "pages": "41-71" }, { "id": "authors:asvtr-zdc09", "collection": "authors", "collection_id": "asvtr-zdc09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160217-110854084", "type": "article", "title": "Effects of H_2O and CO_2 on magma generation in the crust and mantle", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The solution of H_2O, CO_2, and H_2O\u2013CO_2 mixtures in silicate magmas has many effects. Fusion temperatures are lowered, and the fusion and crystallization sequences may be modified. Hydrous minerals and carbonates may become stable within the fusion interval. Liquid compositions are changed as a function of dissolved volatile content, and as a function of H_2O/CO_2. The physical properties of magmas may be influenced markedly by dissolved volatile components. The presence of vapour bubbles arising from exsolution of volatile components during uprise or crystallization of magma may be responsible for physical and geochemical effects. These effects are outlined by examination of the phase relationships in several synthetic systems and rock\u2013H_2O\u2013CO_2 systems. The results demonstrate that H_2O is more influential than CO_2 in magma generation at crustal pressures. The presence of CO_2, however, may influence the evolutionary history of a crustal magma body. In the mantle at depths of 75\u201380 km, the influence of CO_2 becomes as significant as that of H_2O because CO_2 reacts with peridotite stabilizing calcic dolomite, and the solubility of CO_2 increases dramatically. The compositions of near-solidus mantle magmas are strongly influenced by H_2O/CO_2 and by the distribution of carbonate, amphibole and phlogopite in the peridotite. The normal product of crustal anatexis is H_2O-under-saturated granitic liquid. Tonalite liquids can-not be produced by crustal anatexis during normal regional metamorphism.", "issn": "0016-7649", "publisher": "Geological Society", "publication": "Journal of the Geological Society", "publication_date": "1977-11", "series_number": "2", "volume": "134", "issue": "2", "pages": "215-234" }, { "id": "authors:5kt7n-ytv63", "collection": "authors", "collection_id": "5kt7n-ytv63", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-155926046", "type": "article", "title": "Peridotite\u2013CO_2\u2013H_2O, and carbonatitic liquids in the upper asthenosphere", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The recent discovery that CO_2 at upper mantle pressures has a dramatic effect on the melting temperature of peridotite (because the silicate assemblage becomes carbonated), and on the composition of near-solid us liquid, has petrological and geophysical implications that have been explored extensively. The influence of H_2O has received only passing reference, probably because it was tacitly assumed that this would modify the carbonate-dominated melting relationships significantly. I describe here construction of a schematic diagram for the system peridotite\u2013CO_2\u2013H_2O which shows that the carbonate can persist even in the presence of vapours with high H_2O/CO_2 Figure 1 shows that starting with peridotite\u2013H2O at high pressures, a small addition of CO_2 is sufficient for the generation of carbonate. This leads to the unexpected conclusion that many of the applications deduced for the melting of carbonated peridotite may remain valid with vapours enriched in H_2O/CO_2 In particular, the interstitial liquid in the upper part of the seismic low-velocity zone may be carbonatitic even with H_2O present as a component.", "doi": "10.1038/266045a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1977-03-03", "series_number": "5597", "volume": "266", "issue": "5597", "pages": "45-47" }, { "id": "authors:f6486-nsk67", "collection": "authors", "collection_id": "f6486-nsk67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160223-100824017", "type": "article", "title": "Mantle Fluid Compositions Buffered by Carbonates in Peridotite-CO_2-H_2O", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The system CaO-MgO-SiO_2 is a useful approximation for the mantle, including the minerals olivine (Fo), orthopyroxene (Opx), and clinopyroxene (Cpx). In the presence of with increasing pressure, peridotite undergoes a series of carbonation reactions. Each of the univariant carbonation reactions terminates at an invariant point where carbonate and silicates melt together (1250\u00b0-1450\u00b0C with pressures increasing from about 25 kb to 55 kb), producing a carbonate-rich liquid. In the system CaO-MgO-SiO_2-CO_2-H_2O, the carbonation reactions and melting reactions occur at lower temperatures with increasing H_2O content. In the presence of CO_2-H_2O fluids, the mantle peridotite with carbonate acts as a buffer, controlling the CO_2/H_2O ratio as a function of pressure and temperature. Carbon dioxide in the mantle is distributed between calcic dolomite and CO_2-H_2O fluid along normal geotherms, with carbonate, CO_2 and H_2O dissolving in liquid at the top of the asthenosphere. In the absence of phlogopite, the carbonated peridotite buffers the fluid composition towards low CO_2/H_2O ratios, approximately estimated to be 0.4 at 30 kb, and 0.2 at 40 kb. If the ratio of CO_2/H_2O in mantle peridotite exceeds these values, some carbonate is produced, and the buffered pore fluid composition is maintained. Incipient melting of carbonated peridotite produces a carbonatitic liquid, and this is probably true even in the presence of pore fluid enriched in H_2O/CO_2. The interstitial liquid at the top of the seismic low-velocity zone may therefore be carbonatitic, becoming more silicic (but SiO_2-undersaturated-kimberlitic) with increasing depth. Upward migration of this liquid could conceivably produce carbonate-rich peridotites in the lower lithosphere. The compositions of mantle magmas are strongly influenced by the distribution of carbonate, amphibole and phlogopite in the peridotite, as indicated by estimates of their maximum stability ranges on the solidus for peridotite-H_2O-CO_2.", "doi": "10.1086/628285", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1977-03", "series_number": "2", "volume": "85", "issue": "2", "pages": "187-207" }, { "id": "authors:rhgyh-nf950", "collection": "authors", "collection_id": "rhgyh-nf950", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160128-153920004", "type": "article", "title": "Phase relations of portlandite, Ca(OH)_2 and brucite, Mg(OH)_2 to 33 kilobars", "author": [ { "family_name": "Irving", "given_name": "A. J.", "clpid": "Irving-A-J" }, { "family_name": "Huang", "given_name": "W.-L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Using piston-cylinder apparatus, we have extended to 33 kb the dissociation\ncurve for brucite by the quench method and the fusion curves for portlandite dry\nand with excess water vapor by differential thermal analysis. Experimental brackets for\nthe fusion of portlandite are 800\u00b0 to 809\u00b0C al 10 kb, 796\u00b0 to 800\u00b0C at 20 kb, and\n781\u00b0 to 786\u00b0C at 30 kb, and for the fusion of portlandite with excess vapor 715\u00b0 to\n719\u00b0C at 10 kb, 675\u00b0 to 682\u00b0C at 20 kb, 643\u00b0 to 649\u00b0C at 30 kb. Experimental brackets\nfor the brucite dehydration are 920\u00b0 to 940\u00b0C at 17 kb, 1050\u00b0C at 27 kb, and 1080\u00b0 to\n1100\u00b0C at 33 kb; the 33 kb bracket was reversed; one DTA run at 27 kb gave 1055\u00b0 \u00b1\n7\u00b0C, overlapping the definitive quench run. We find no evidence for the previously\nreported temperature maximum on the brucite dehydration curve at 32 kb. From the\nexperimental data for the brucite reaction, values calculated for the Gibbs free energy\nfunction, G*, of water arc -15.325 kcal mole^(-1) at 17 kb, 930\u00b0C; -6.647 kcal mole^(-1)\nat 27 kb, 1050\u00b0C; and -2.997 kcal mole^(-1) at 33 kb, 1090\u00b0C.", "doi": "10.2475/ajs.277.3.313", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1977-03", "series_number": "3", "volume": "277", "issue": "3", "pages": "313-321" }, { "id": "authors:xqs49-v7g68", "collection": "authors", "collection_id": "xqs49-v7g68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160330-101138391", "type": "article", "title": "Does CO_2 cause partial melting in the low-velocity layer of the mantle?: Comment and reply", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "W.-L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Eggler", "given_name": "David H.", "clpid": "Eggler-D-H" } ], "abstract": "It is gratifying that Eggler (1976a) shares our conclusion that\nif CO_2 exists in the upper mantle it would cause partial melting\nand thus account for the low-velocity zone (Wyllie and Huang,\n1975a, 1975b), but less satisfying that he disputes our petrological\nconclusions. His charge that these are premature needs\nrebuttal because they have topical applications in petrology and\ngeophysics. Eggler (1976a) stated, \"It is difficult to evaluate why\nmy results differ from those of Wyllie and Huang. . . . both\nsets of results involve a certain amount of extrapolation and\ninference.\" The extent of extrapolation can be seen in Figures 1\nand 3. Figures 2 and 3 summarize the main differences.", "doi": "10.1130/0091-7613(1976)4<712:DCCPMI>2.0.CO;2", "issn": "0091-7613", "publisher": "Geological Society of America", "publication": "Geology", "publication_date": "1976-12", "series_number": "12", "volume": "4", "issue": "12", "pages": "712-789" }, { "id": "authors:kmspf-9wk53", "collection": "authors", "collection_id": "kmspf-9wk53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-140145610", "type": "article", "title": "Granitic magmas: possible and impossible sources, water contents, and crystallization sequences", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Stern", "given_name": "Charles R.", "clpid": "Stern-C-R" }, { "family_name": "Maal\u00f8e", "given_name": "Sven", "clpid": "Maal\u00f8e-S" } ], "abstract": "The calc-alkalic rocks of batholiths or their precursors may be generated in deep continental crust, in subducted oceanic crust, in the mantle wedge above, or in processes involving material from all three sources. For the series gabbro\u2013tonalite\u2013granite, we have phase relationships with excess H_2O to 35\u2002kbar (3500\u2002MPa), and the H_2O-undersaturated liquidus surfaces mapped with contours for H2O contents and with fields for near-liquidus minerals. Isobaric diagrams with low H_2O contents provide grids potentially useful in defining limits for the H_2O content of magmas, based on the sequence of crystallization. Conclusions from the experimental framework include: (1) The H_2O content of large granitic bodies is less than 1.5%. (2) Primary granite magmas can not be derived from the mantle or subducted ocean crust. (3) Primary granite magmas with low H_2O content are generated in the crust, and erupted as rhyolites. (4) Primary tonalite and andesite are not generated from mantle peridotite; the H_2O contents required are unrealistically high. (5) Primary tonalite and andesite are not generated in the crust unless temperatures are significantly higher than those of regional metamorphism. (6) Subducted ocean crust yields magmas with intermediate SiO_2 content, but not primary tonalite and andesite. (7) Batholiths are produced from crustal rocks as a normal consequence of regional metamorphism, with the formation of H_2O-undersaturated granite liquid and mobilized migmatites. Some batholiths receive in addition contributions of material and heat from mantle and subducted ocean crust.", "doi": "10.1139/e76-104", "issn": "0008-4077", "publisher": "NRC Research Press", "publication": "Canadian Journal of Earth Sciences", "publication_date": "1976-08", "series_number": "8", "volume": "13", "issue": "8", "pages": "1007-1019" }, { "id": "authors:svxdy-f3r27", "collection": "authors", "collection_id": "svxdy-f3r27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-133932099", "type": "article", "title": "Petrogenetic grid for siliceous dolomites extended to mantle peridotite compositions and to conditions for magma generation", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" } ], "abstract": "Decarbonation reactions in the system CaO-MgO-SiO_2-CO_2 involve calcite, dolomite,\nmagnesite, and quartz, and the products enstatite, forsterite, diopside, and wollastonite,\namong others. Each decarbonation reaction terminates at an invariarit point involving a\nliquid, CO_2 vapor, carbonate minerals, and one or more of the silicate minerals. Fusion curves\nfor mantle mineral assemblages involving forsterite, orthopyroxene, and clinopyroxene in the\npresence of CO_2, extending from higher temperature regions, terminate at these same invariant\npoints. The points are connected by a series of liquidus reactions involving the\ncarbonates and mantle silicates, at temperatures generally lower than the silicate-CO_2 melting\nreactions. Experimental data and theoretical analysis permit construction of a series of partly\nschematic phase diagrams. Petrological and geophysical conclusions include the following: (1)\nFree CO_2 cannot exist in the mantle; it is stored as carbonate. (2) CO_2 appears to be as\neffective as H_2O in causing incipient melting of mantle peridotite, and this remains our\npreferred explanation for the seismic low-velocity zone. (3) At depths greater than about 80\nkm, mantle peridotite with CO_2 (as carbonate) yields carbonatitic magmas with about 40\npercent CO_2 and 10 percent silicates in solution; with progressive fusion the liquid becomes\nkimberlitic. (4) Primary carbonatite or kimberlite magmas rising from the asthenosphere must\nevolve CO_2 near 80 km depth, which would contribute to their explosive eruption. (5)\nThrough a wide pressure range, SiO_2-undersaturated basic magmas with CO_2 in solution can\nyield residual kimberlitic or carbonatitic magmas. (6) Deep mantle magmas may include the\ncarbonated alkali ultrabasic magmas that have been proposed as the parents from which\ncontinental associations of highly alkalic rocks are derived.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1976-07", "series_number": "7-8", "volume": "61", "issue": "7-8", "pages": "691-698" }, { "id": "authors:kdwxd-gjy32", "collection": "authors", "collection_id": "kdwxd-gjy32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-145342775", "type": "article", "title": "Carbonation and melting reactions in the system CaO-MgO-SiO_2-CO_2 at mantle pressures with geophysical and petrological applications", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" } ], "abstract": "Bowen's petrogenetic grid was based initially on a series of decarbonation reactions in the system CaO-MgO-SiO_2-CO_2 with starting assemblages including calcite, dolomite, magnesite and quartz, and products including enstatite, forsterite, diopside and wollastonite. We review the positions of 14 decarbonation reactions, experimentally determined or estimated, extending the grid to mantle pressures to evaluate the effect of CO_2 on model mantle peridotite composed of forsterite(Fo)+orthopyroxene(Opx)+clinopyroxene(Cpx). Each reaction terminates at an invariant point involving a liquid, CO_2, carbonates, and silicates. The fusion curves for the mantle mineral assemblages in the presence of excess CO_2 also terminate at these invariant points. The points are connected by a series of reactions involving liquidus relationships among the carbonates and mantle silicates, at temperatures lower (1,100\u20131,300\u00b0 C) than the silicate-CO_2 melting reactions (1,400\u20131,600\u00b0 C). Review of experimental data in the bounding ternary systems together with preliminary data for the system CaO-MgO-SiO_2-CO_2 permits construction of a partly schematic framework for decarbonation and melting reactions at upper mantle pressures. The key to several problems in the peridotite-CO_2 subsystem is the intersection of a subsolidus carbonation reaction with a melting reaction at an invariant point near 24 kb and 1,200\u00b0C. There is an intricate series of reactions between 25 kb and 35 kb involving changes in silicate and carbonate phase fields on the CO_2-saturated liquidus surfaces. Conclusions include the following: (1) Peridotite Fo+Opx+Cpx can be carbonated with increasing pressure, or decreasing temperature, to yield Fo+Opx+Cpx+Cd (Cd=calcic dolomite), Fo+Opx+Cd, Fo+Opx+Cm (Cm=calcic magnesite), and finally Qz+Cm. (2) Free CO_2 cannot exist in subsolidus mantle peridotite with normal temperature distributions; it is stored as carbonate, Cd. (3) The CO_2 bubbles in peridotite nodules do not represent free CO_2 in mantle peridotite along normal geotherms. (4) CO_2 is as effective as H_2O in causing incipient melting, our preferred explanation for the low-velocity zone. (5) Fusion of peridotite with CO_2 at depths shallower than 80 km produces basic magmas, becoming more SiO_2-undersaturated with depth. (6) The solubility of CO_2 in mantle magmas is less than about 5 wt% at depths to 80 km, increasing abruptly to about 40 wt% at 80 km and deeper. (7) Deeper than 80 km, the first liquids produced are carbonatitic, changing towards kimberlitic and eventually, at considerably higher temperatures, to basic magmas. (8) Kimberlite and carbonatite magmas rising from the asthenosphere must evolve CO_2 at depths 100-80 km, which contributes to their explosive emplacement. (9) Fractional crystallization of CO_2-bearing SiO_2-undersaturated basic magmas at most pressures can yield residual kimberlite and carbonatite magmas.", "doi": "10.1007/BF00372117", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1976-06", "series_number": "2", "volume": "54", "issue": "2", "pages": "79-107" }, { "id": "authors:147xn-mmn16", "collection": "authors", "collection_id": "147xn-mmn16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-112502925", "type": "article", "title": "Geophysical measurements and experimental petrology", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Schreyer", "given_name": "Werner", "clpid": "Schreyer-W" } ], "abstract": "Experimental petrology is the materials science of geophysical sciences. When packages of rock material move through the earth, as they do according to recent earth models, they undergo phase transitions and changes in state, but they do not necessarily maintain a condition of thermodynamic equilibrium. Geophysical measurements are interpreted in terms of the properties of materials in different volumes within the earth ; petrological studies provide clues about the materials involved ; and the results of experimental petrology show the equilibrium state of each material as a function of pressure and temperature. For the satisfactory correlation of geophysical measurements with the results of experimental petrology, we have to map the fields on phase diagrams for materials in terms of physical properties, and to determine the kinetics of the mineralogical changes and phase transitions involved. The subject of this symposium is evaluation of the present state of this correlation in the context of plate tectonics.", "doi": "10.1016/0040-1951(76)90083-4", "issn": "0040-1951", "publisher": "Elsevier", "publication": "Tectonophysics", "publication_date": "1976-05", "series_number": "1-2", "volume": "32", "issue": "1-2", "pages": "1-6" }, { "id": "authors:4vc0c-nzm84", "collection": "authors", "collection_id": "4vc0c-nzm84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160330-091127871", "type": "article", "title": "High CO_2 solubilities in mantle magmas: Comment and reply", "author": [ { "family_name": "Eggler", "given_name": "David H.", "clpid": "Eggler-D-H" }, { "family_name": "Holloway", "given_name": "John R.", "clpid": "Holloway-J-R" }, { "family_name": "Bj\u00f8rn", "given_name": "Mysen", "clpid": "Bj\u00f8rn-M" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" } ], "abstract": "The two \"arguments\" discussed in the comment by Eggler\nand others exclude direct reference to what we consider to be the\nthree main conclusions of the paper by Wyllie and Huang (1976).\nThese conclusions should clarify the points made by Eggler and\nothers; in fact, we have large areas of agreement. We agree on\nthe following two points for systems such as CaO-MgO-SiO_2-CO_2:\n\n1. For a liquid of fixed oxide/SiO_2 ratio, the CO_2 solubility\nincreases progressively with increasing pressure. For compositions\nsimilar to common silicate magmas, the CO_2 solubility remains\nbelow 5 to 8 percent up to 30 kb.\n\n2. At fixed pressure, the CO_2 solubility increases from SiO_2\nto the oxide or oxides, with maximum values at 30 kb near\n45 percent for the oxides (molten carbonates).", "doi": "10.1130/0091-7613(1976)4<199:HCSIMM>2.0.CO;2", "issn": "0091-7613", "publisher": "Geological Society of America", "publication": "Geology", "publication_date": "1976-04", "series_number": "4", "volume": "4", "issue": "4", "pages": "199-200" }, { "id": "authors:hwwb4-xzg51", "collection": "authors", "collection_id": "hwwb4-xzg51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160128-152536459", "type": "article", "title": "Melting relationships in the systems CaO-CO_2 and MgO-CO_2 to 33 kilobars", "author": [ { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The melting temperatures of calcite and magnesite in the presence of excess CO_2 have been measured using Ag_2C_2O_4 in sealed capsules m a piston-cylinder apparatus. At 27 kbar, 11.5 wt % CO_2 dissolves in molten CaCO_2, depressing the freezing temperature from 1610 to 1505\u00b0C; and 6.5 wt % CO_2 dissolves in molten MgCO_3, depressing the freezing temperature from 1590 to 1510\u00b0C. The eutectic between calcite and lime was located at 1385\u00b0C at 27 kbar. These and other new results, combined with previously published data, permit completion of PT diagrams for the systems CaO-CO_2 and MgO-CO_2 from 1 bar to 35 kbar. The dissociation curve for each carbonate terminates at an invariant point where melting begins, at 40 bars and 1230\u00b0C for CaO-CO_2 and 23 kbar and 1550\u00b0C for MgO-CO_2 The differences between the two systems are explained by the different solubilities of CO_2 in the invariant liquids consequent upon the large pressure difference between the locations of these two invariant points. The results show that the temperatures for the beginning of melting of carbonates in the asthenosphere are lowered by about 100\u00b0C in the presence of CO_2.", "doi": "10.1016/0016-7037(76)90169-1", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1976-02", "series_number": "2", "volume": "40", "issue": "2", "pages": "129-132" }, { "id": "authors:wsxb1-xxm56", "collection": "authors", "collection_id": "wsxb1-xxm56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-113418220", "type": "article", "title": "High CO_2 solubilities in mantle magmas", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" } ], "abstract": "Phase diagrams for the assemblage forsterite+enstatite+CO_2 in MgO-SiO_2-CO_2 show that a subsolidus carbonation reaction intersects the solidus near 44 kb\u20131530\u00b0C and stabilizes the carbonate molecule in the liquid, causing CO_2 solubility to increase from about 5 to 10 wt percent to about 40 wt percent. A similar increase occurs in the system CaO-MgO-SiO_2-CO_2 near 25 kb\u20131200\u00b0C for the liquid coexisting with forsterite+orthopyroxene+ clinopyroxene. The CO_2 solubility in diopside and enstatite liquids remains relatively low, because these are not involved in carbonation reactions at this pressure. This accounts for contrasted CO_2 solubilities in silicate melts reported in recent experimental studies. Magmas generated in a CO_2-bearing mantle below a depth of 80 km may contain up to 40 wt percent dissolved CO_2. CO_2-rich, SiO_2-undersaturated magmas can coexist with mantle peridotite through a wide temperature range. These could represent either primary carbonatite and kimberlite magmas or the carbonated alkali ultrabasic magmas cited by many petrologists as parents for the derivation of continental volcanic and plutonic associations of highly alkalic rocks.", "doi": "10.1130/0091-7613(1976)4<21:HCSIMM>2.0.CO;2", "issn": "0091-7613", "publisher": "Geological Society of America", "publication": "Geology", "publication_date": "1976-01", "series_number": "1", "volume": "4", "issue": "1", "pages": "21-24" }, { "id": "authors:m8h4k-vt748", "collection": "authors", "collection_id": "m8h4k-vt748", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-101257084", "type": "article", "title": "The join grossularite-calcite through the system CaO-Al_2O_3-SiO_2-CO_2 at 30 kilobars: Crystallization range of silicates and carbonates on the liquidus", "author": [ { "family_name": "Maal\u00f8e", "given_name": "Sven", "clpid": "Maal\u00f8e-S" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "At 30 kbar, calcite melts congruently at 1615\u00b0C, and grossularite melts incongruently to liquid + gehlenite (tentative identification) at 1535\u00b0C. The assemblage calcite + grossularite melts at 1450\u00b0C to produce liquid + vapor, with piercing point at about 49 wt.% CaCO_3. Vapor phase is present in all hypersolidus phase fields except for those with less than about 7% CaCO_3 or 8% Ca_3Al_2Si_3O_(12). These results, together with known liquidus data for CaO\u2014SiO_2\u2014CO_2 and inferred results for CaO\u2014Al_2O_3\u2014CO_2 and Al_2O_3\u2014SiO_2\u2014CO_2, permit construction of the position of the CO_2- saturated liquidus surface in the quaternary system, and estimation of the positions of liquidus field boundaries separating some of the primary crystallization fields on this surface. The field of calcite is separated from those for grossularite and quartz by a field boundary with about 50% dissolved CaCO_3. Crystallization paths of silicate liquids in the range Ca_2SiO_4\u2014Ca_3Al_2Si_3O_(12)\u2014SiO_2, with some dissolved CO_2, will terminate at a quaternary eutectic on this field boundary, with the precipitation of calcite together with grossularite and quartz, at a temperature below 1450\u00b0C. Addition of Al_2O_3 to CaO\u2014SiO_2\u2014CO_2 in amounts sufficient to stabilize garnet thus causes little change in the general liquidus pattern as far as carbonates and silicates are concerned. With addition of MgO, we anticipate that silicate liquids with dissolved CO_2 will also follow liquidus paths to fields for the precipitation of carbonates; we conclude that similar paths link kimberlite and some carnbonatite magmas.", "doi": "10.1016/0012-821X(75)90228-9", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1975-12", "series_number": "2", "volume": "28", "issue": "2", "pages": "205-208" }, { "id": "authors:pc2xe-7r421", "collection": "authors", "collection_id": "pc2xe-7r421", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160128-151921847", "type": "article", "title": "Basalt-andesite-rhyolite-H_2O: Crystallization intervals with excess H_2O and H_2O-undersaturated liquidus surfaces to 35 kolbras, with implications for magma genesis", "author": [ { "family_name": "Stern", "given_name": "Charles R.", "clpid": "Stern-C-R" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Three rocks representing the calc-alkaline rock series gabbro-tonalite-granite or basalt-andesite-rhyolite were reacted with varying percentages of water in sealed capsules between 600 and 1300\u00b0C and pressures to 36 kbars, corresponding to depths of more than 120 km within the earth. For each rock we present complete P-T diagrams with excess water, and the water-undersaturated liquids surface projected from P-T-X_(H_2O) space mapped with contours for constant H_2O contents and with the fields for near-liquidus minerals. All changes in liquidus and solidus slopes can be correlated with changes in mineralogy from less dense to more dense, or with expansion of crystallization fields, without appeal to changes in molar volume of H_2O in liquid and vapor phases. The results indicate that tholeiites and andesites of the calc-alkaline series with compositions similar to the rocks studied are not primary magmas from mantle peridotite at depths greater than about 50 km. Primary andesitic magmas from shallower levels would require very high water contents and we do not believe such magmas could normally reach the surface. The liquids results are consistent with the derivation of andesites with little dissolved water as primary magmas from subducted ocean crust (quartz eclogite), but multi-stage models are preferred. Temperatures required for the generation of andesites by fusion of continental crust are higher than considered reasonable. The evidence precludes the generation of primary rhyolites or granites from the mantle of subducted oceanic crust at mantle depths. Primary rhyolite or granite magmas with moderate water contents (saturated or undersaturated) can be generated in the crust at reasonable temperatures, and could reach near-surface levels before vesiculation. Water-undersaturated granite liquid with residual crustal minerals could constitute plutonic magmas of intermediate composition.", "doi": "10.1016/0012-821X(75)90226-5", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1975-12", "series_number": "2", "volume": "28", "issue": "2", "pages": "189-196" }, { "id": "authors:jpep1-8sq20", "collection": "authors", "collection_id": "jpep1-8sq20", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160212-131925115", "type": "article", "title": "Melting Reactions in the System NaAlSi_3O_8-KAlSi_3O_8-SiO_2 to 35 Kilobars, Dry and with Excess Water", "author": [ { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Piston-cylinder apparatus was used to determine the univariant minimum melting reaction in the dry system Ab-Or-Qz to 30 kb, and to extend the corresponding curve with excess water from 20 kb to 35 kb. At 30 kb, temperatures of the two univariant curves are 1,235\u00b0C and 680\u00b0C, respectively. The new data and other published data are combined to produce a complete P-T diagram for univariant reactions in the system Ab-Or-Qz-H_2O above 500\u00b0C, and phase diagrams comparing the effect of pressure on field boundaries in the systems Ab-Or-Qz-H_2O and Ab-Or-Qz. The slopes (dP/dT) of the excess water reactions change from negative to positive at pressures where the feldspars are replaced by denser minerals: about 17 kb where jadeite is formed from albite, and 27-30 kb where sanidine is replaced by sanidine hydrate. The liquidus volume for the primary crystallization of quartz increases with pressure, and above 10 kb the effect is greater in the dry system than in the water-saturated system. This accounts for the increased melting interval of granites with increasing pressure, and the wider interval beneath the liquidus of granites for the crystallization of quartz (or coesite) without accompanying feldspar. Partial fusion of metamorphosed feldspathic sediments in deeply subducted oceanic crust would produce a liquid with only a few per cent normative quartz; the initial liquid would be closer to a trachyte than a normal rhyolite. The results are consistent with the conclusion from other experiments that primary granites and ryolites cannot be derived from subduction zones at depths of 100 km or so.", "doi": "10.1086/628165", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1975-11", "series_number": "6", "volume": "83", "issue": "6", "pages": "737-748" }, { "id": "authors:hchzn-jc931", "collection": "authors", "collection_id": "hchzn-jc931", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160322-093050760", "type": "article", "title": "Peridotite, kimberlite, and carbonatite explained in the system CaO-MgO-SiO_2-CO_2", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" } ], "abstract": "The key to the origin of carbonatite and kimberlite lies in the system CaO-MgO-SiO_2-CO_2. Increase in pressure causes a carbonation reaction in the peridotite assemblage as follows: forsterite + clinopyroxene + CO_2 \u21cc orthopyroxene + carbonate (Ca:Mg::70:30). This reaction passes through 15 kb\u2013960\u00b0C with slope 45 b/\u00b0C and terminates at an invariant point near 25 kb-1200\u00b0C, where melting begins. This intersection of the carbonation reaction with the solidus introduces primary carbonate minerals alongside peridotite minerals on the liquidus surface. At 20 kb the melting temperature of the peridotite assemblage Fo + Opx + Cpx is lowered 75\u00b0C by solution of about 5 wt percent CO_2. The liquid corresponds to undersilicated basic magma. Stabilization of carbonate increases CO_2 solubility in the liquid, and above 25 kb the liquidus reaction involving Fo + Opx + Cpx + CO_2 sweeps down through 400\u00b0C via a pressure maximum at 32 kb to meet the invariant point at 25 kb. The peridotite solidus curve at higher pressures involves fusion of silicates and carbonates, producing a carbonatitic liquid with more than 45 wt percent CO_2. Progressive fusion produces a kimberlitic liquid. There is an intricate series of reactions between 25 kb and 35 kb involving changes in silicate and carbonate phase fields on the CO_2-saturated liquidus surface. Fractional crystallization of CO_2-bearing under-silicated basic magmas at most pressures yields residual kimberlite and carbonatite. Kimberlite and carbonatite magmas rising from the asthenosphere evolve CO_2 as they reach a reaction boundary at a depth of about 100 to 80 km. This contributes to their explosive eruption. Free CO_2 cannot coexist with subsolidus mantle peridotite with normal temperature distributions. CO_2 appears to be as effective as H_2O in causing incipient melting in the asthenosphere.", "doi": "10.1130/0091-7613(1975)3<621:PKACEI>2.0.CO;2", "issn": "0091-7613", "publisher": "Geological Society of America", "publication": "Geology", "publication_date": "1975-11", "series_number": "11", "volume": "3", "issue": "11", "pages": "621-624" }, { "id": "authors:apwr1-a4j56", "collection": "authors", "collection_id": "apwr1-a4j56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-130856739", "type": "article", "title": "Influence of mantle CO_2 in the generation of carbonatites and kimberlites", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" } ], "abstract": "The explanation of why partial fusion of mantle peridotite sometimes yields basalts, sometimes kimberlites and sometimes carbonatites is given by the phase relationships in the system CaO\u2013MgO\u2013SiO_2\u2013CO_2. The key is the intersection of a sub-solidus carbonation reaction with the solidus, which introduces carbonates as primary minerals alongside silicates on the surface of the liquidus.", "doi": "10.1038/257297a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1975-09-25", "series_number": "5524", "volume": "257", "issue": "5524", "pages": "297-299" }, { "id": "authors:rrex0-r2980", "collection": "authors", "collection_id": "rrex0-r2980", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-155606554", "type": "article", "title": "Water content of a granite magma deduced from the sequence of crystallization determined experimentally with water-undersaturated conditions", "author": [ { "family_name": "Maal\u00f8e", "given_name": "Sven", "clpid": "Maal\u00f8e-S" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The sequence of crystallization in a biotite-granite from the Bohus batholith of Norway and Sweden, deduced from its texture, was magnetite, plagioclase, microcline, quartz, and finally biotite. Several sequences of crystallization were determined experimentally at 2 kb in the presence of varying only for H_2O contents below 1.2% by weight. The rock was fused to a homogeneous glass, and each experiment included samples of finely crushed rock and glass. The samples were reacted in Ag-Pd capsules with measured H_2O content in coldseal pressure vessels with NNO buffer. With excess H_2O (more than 6.5%) the crystallization interval extends from 865\u00b0 C to 705\u00b0 C. In the H_2O-deficient region, the solidus temperature remains unchanged as long as a trace of vapor is present, but the liquidus temperature increases as H_2O content decreases; with 0.8 % H_2O the liquidus temperature is 1125\u00b0 C, the crystallization interval is 420\u00b0 C, and a separate aqueous vapor phase is evolved only a few degrees above the solidus at 705\u00b0 C. The biotite phase boundary increases slightly from 845\u00b0 C with excess H_2O to 875\u00b0 C with 1% H_2O, and it intersects the steep phase boundaries for quartz and feldspars; the sequence of crystallization changes at each intersection point. Similar diagrams at various pressures for related rock compositions involving muscovite, biotite and amphibole will provide grids useful in defining limits for the water content of granitic and dioritic magmas. Applications are considered for the Bohus batholith, other granitic rocks, and rhyolites. The Bohus magma could have been formed by crustal anatexis as a mobile assemblage of H_2O-undersaturated liquid and residual crystals with initial total H_2O content less than 1.2%, or it could have been derived by fractionation of a more basic parent with low H_2O content from mantle or subduction zone, but it could not have been derived from a primary andesite generated from mantle peridotite. We consider it unlikely that the H_2O content of large granitic magma bodies exceeds about 1.5% H_2O; these magmas are H_2O-undersaturated through most of their histories. Uprise and progressive crystallization of magma bodies produces H_2O-saturation around margins and in the upper regions of magma chambers. H_2O-saturated rhyolitic and dacitic magmas with phenocrysts can be tapped from the upper parts of the magma chambers.", "doi": "10.1007/BF00457293", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1975-09", "series_number": "3", "volume": "52", "issue": "3", "pages": "175-191" }, { "id": "authors:veqjx-7ya43", "collection": "authors", "collection_id": "veqjx-7ya43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-084320072", "type": "article", "title": "Effect of iron absorption by noble-metal capsules on phase boundaries in rock-melting experiments at 30 kilobars", "author": [ { "family_name": "Stern", "given_name": "C. R.", "clpid": "Stern-C-R" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Andesite-H_2O and basalt-H_2O mixtures encapsulated in Pt, Ag_(30)Pd_(70), and Ag_(75)Pd_(25) with\nhigh ratios of metal/sample were run in half-inch diameter piston-cylinder apparatus at 30\nkbar at temperatures where the mixtures were molten or partly crystallized. For andesite\nliquid at l 100\u00b0C the rate of iron absorption by the capsules is greatest in the first hour, 70\npercent of initial FeO being lost with Pt capsules. After 3 hours, percentages of initial FeO\nlost are 85 percent for Pt, 35 percent for Ag_(30)Pd_(70), and 25 percent for Ag_(75)Pd_(25). For the phase\nassemblage garnet(Ga) + clinopyroxene(Cpx) + liquid(L) with 80 percent L at 1100\u00b0C in\nAg_(75)Pd_(25) capsules, clinopyroxene and liquid lose about 30 percent FeO in the 4-hour interval\nbetween 1 and 5 hour runs, but garnet does not change composition. Distribution coefficients\nfor Fe and Mg between liquid and minerals therefore vary as a function of run duration. At\n1000\u00b0C and below, iron loss is not a serious problem in Ag_(30)Pd_(70) for runs of 10 hours duration,\nbut attempts to reverse the Cpx-out phase boundary in andesite-10% H_2O near 950\u00b0C\ndemonstrate kinetic and nucleation problems; the reversal bracket is wide, 890\u00b0-975\u00b0C. Consistency\nbetween one-stage and two-stage low-to-high temperature runs for andesite and\nbasalt with at least 10 percent H_2O between 1050\u00b0C and 1200\u00b0C suggests a close approach to\nequilibrium for garnet and clinopyroxene after 1-hour runs. For runs with basalt-H_2O in Pt\ncapsules, longer runs cause the recorded positions of the Cpx-out and Ga-out phase boundaries\nto increase and decrease in temperature, respectively, with discrepancies of 25-50\u00b0C\nbetween runs of 1 hour and 12 hours. This makes it difficult to demonstrate reversible\nequilibrium of a high-temperature phase boundary in a rock-H_2O system; reversibility in a\nsystem of changing bulk composition is not necessarily an equilibrium condition.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1975-07", "series_number": "7-8", "volume": "60", "issue": "7-8", "pages": "681-689" }, { "id": "authors:00yb9-fny07", "collection": "authors", "collection_id": "00yb9-fny07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160212-130637661", "type": "article", "title": "Compositions of Glasses from St. Paul's Peridotite Partially Melted at 20 Kilobars", "author": [ { "family_name": "Nehru", "given_name": "C. E.", "clpid": "Nehru-C-E" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "St. Paul's peridotite with 5.7% H_\u2082O (considered to be derived from the upper mantle) was partially-melted at 20 kb in Ag_(75)Pd_(25) and Pt capsules with run durations up to 17 hours. Run products were analyzed for Fe, Mg, Ca, and Al using an electron microprobe. FeO loss from sample to capsule wall increased with temperature and run duration and was as much as 90% in Pt capsules at 1,250\u00b0C and 4 hours, and 73% at 1,150\u00b0C and 17 hours in Ag_(75)Pd_(25) capsules. Iron loss was lower in larger Pt capsules with a higher sample/platinum ratio. The amount of liquid produced in runs increased as a function of run duration, confirming the nonequilibrium condition. It was difficult to measure the composition of glass in narrow seams and wedges between mineral boundaries, and the problem was compounded by the presence of numerous minute olivine grains from the mylonite starting material and of quench amphibole in the glass. Glass compositions were estimated from analyses of glassy areas and quench amphiboles, and the compositional trend between 1,100\u00b0C and 1,250\u00b0C was plotted on variation diagrams. Expressed in terms of Al_\u2082O_\u2083 and CaO only, the glass analyses are similar to andesite and tholeiite. Our estimated glass compositions are compared with published data for measured glasses from partially melted peridotites of similar composition. In terms of the four elements that we analyzed the compositions of glasses vary considerably from one set of experimental conditions to another. We conclude that this is due in part to the experimental problems outlined above. The best results that can be achieved represent a compromise between runs long enough to ensure reaction and short enough to minimize the changing composition of the reacting system through iron loss.", "doi": "10.1086/628122", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1975-07", "series_number": "4", "volume": "83", "issue": "4", "pages": "455-471" }, { "id": "authors:ar5aa-9jp40", "collection": "authors", "collection_id": "ar5aa-9jp40", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-082909937", "type": "article", "title": "Kaersutite and Kaersutite Eclogite from Kakanui, New Zealand \u2014 Water-Excess and Water-Deficient Melting to 30 Kilobars", "author": [ { "family_name": "Merrill", "given_name": "R. B.", "clpid": "Merrill-R-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "A natural kaersutite megacryst (compositionally equivalent to olivine nephelinite) and a kaersutite eclogite nodule (equivalent to olivine basanite) from the Mineral Breccia, Kakanui, New Zealand, were reacted in sealed platinum and Pd_(70)Ag_(30) alloy capsules, both with excess water and no additional water present, using half-inch piston-cylinder apparatus. Near-liquidus assemblages include orthopyroxene at pressures greater than about 15 kb in water-rich portions of the olivine-basanite system but not in the olivine-nephelinite system. Reversed high-pressure limits of the amphibole stability fields (excess water) have negative values of dP/dT, which crosses 25 kb at 1075\u00b0C and 30 kb at 925\u00b0C in the kaersutite system, but which crosses 25 kb at 1025\u00b0C and 30 kb at about 775\u00b0C in the kaersutite eclogite system. Comparison with experimental results reported elsewhere indicates that amphiboles persist to highest temperatures in basaltic liquids with greatest TiO_2 contents but with lowest Na_2O/(Na_2O + K_2O) ratios and lowest SiO_2 contents. \nExperimental results suggest that many natural nephelinite and basanite magmas evolve from hydrous picritic parent magmas through deep-seated fractionation of olivine, possibly with clinopyroxene and garnet but excluding orthopyroxene. Although some olivine-rich basanitic liquids may be generated by partial fusion of hydrous mantle peridotite, it is unlikely that orthopyroxene fractionation is important in their subsequent evolution. \nExperimental observations, together with chemical and petrographic relations, support the following model petrogenetic history for the Kakanui Mineral Breccia: pyrope-rich garnet and omphacitic pyroxene precipitated from ascending hydrous alkali basaltic magma (75 to 85 km, 1200\u00b0 to 1300\u00b0C), then became trapped in deep-seated pockets within Iherzolitic mantle, together with inter-cumulus liquid that precipitated kaersutite on cooling. Resulting kaersutite eclogite assemblages re-equilibrated subsolidus (75 to 85 km, 700\u00b0 to 800\u00b0C) prior to being incorporated into a rapidly ascending hydrous nephelinite magma, which was coprecipitating garnet, clinopyroxene, and probably kaersutite at depths >75 km (1100\u00b0 to 1200\u00b0C). These accidental eclogitic inclusions underwent partial melting during the subsequent rapid ascent, which was terminated by an explosive eruption.", "doi": "10.1130/0016-7606(1975)86<555:KAKEFK>2.0.CO;2", "issn": "0016-7606", "publisher": "Geological Society of America", "publication": "Geological Society of America Bulletin", "publication_date": "1975-04", "series_number": "4", "volume": "86", "issue": "4", "pages": "555-570" }, { "id": "authors:vzjfq-ktz26", "collection": "authors", "collection_id": "vzjfq-ktz26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-140423147", "type": "article", "title": "The Earth's Mantle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "This great body of hot rock accounts for 83 percent of the volume of the earth and 67 percent of its mass. Although the mantle is inaccessible, much has been learned about it by indirect evidence.", "issn": "0036-8733", "publisher": "Scientific American", "publication": "Scientific American", "publication_date": "1975-03", "series_number": "3", "volume": "232", "issue": "3", "pages": "50-63" }, { "id": "authors:56s02-4by73", "collection": "authors", "collection_id": "56s02-4by73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-112051585", "type": "article", "title": "Melting and Subsolidus Phase Relationships for CaSiO_3 to 35 Kilobars Pressure", "author": [ { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase transitions between pseudowollastonite, wollastonite I, and wollastonite II have been reversed in\npiston-cylinder apparatus, and the melting curve for these CaSiO, polymorphs has been determined\nbetween 10 and 35 kbars. The pseudowollastonite melting curve rises from 1544\u00b0C at 1 bar with an unusually\nsteep slope (dP/dT = 580 bar/\u00b0C) to a triple point at 1588\u00b0C and 23 kbar, where the solidus meets\nthe transition from pseudowollastonite to wollastonite I, rising from 1125\u00b0C at 1 bar. The transition\nboundary between wollastonite I and wollastonite II has a shallow, negative slope (dP/dT = -8.4\nbar/ \u00b0C); the triple point where it reaches the solidus is at 1598\u00b0C and 27.5 kbar. The slope of the fusion\ncurve decreases at each triple point, and dP/dT for wollastonite II, 192 bar/\u00b0C, is much closer to that of\nother silicates, such as diopside, enstatite, and albite, than to wollastonite I. Refractive indices of glasses\nquenched from high pressure CaSiO, and CaMgSi_2O_8 liquids vary less as a function of pressure than do\nindices of glasses quenched from feldspars and feldspathic liquids. Either the densities of liquids of inosilicates\nare changed less than those of tektosilicates by pressure, or their high pressure densities are not\nquenched into the glasses.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1975-03", "series_number": "3-4", "volume": "60", "issue": "3-4", "pages": "213-217" }, { "id": "authors:zxshh-3jz03", "collection": "authors", "collection_id": "zxshh-3jz03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-144703664", "type": "article", "title": "Subsolidus and melting relationships for calcite, magnesite and the join CaCO_3-MgCO_3 to 36 kb", "author": [ { "family_name": "Irving", "given_name": "Anthony J.", "clpid": "Irving-A-J" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Subsolidus and melting relations for the CaCO_3-MgCO_3 join at 30 kb have been determined using piston-cylinder apparatus. Data are also presented for the melting curve of CaCO_3 to 30 kb, the decomposition and melting curves of MgCO_3 to 36 kb, and the calcite-aragonite transition at 800\u00b0C, 950\u00b0C and 1100\u00b0C. At 30kb, the melting loop for the CaCO_3-MgCO_3 join extends from 1610\u00b0C (CaCO_3) to 1585\u00b0C (MgCO_3) through a liquidus minimum at 1290\u00b0C (near 42 mole% MgCO_3). The dolomite-magnesite solvus barely intersects the 30 kb melting loop to produce a peritectic reaction at 1385\u00b0C. Integration of the new experimental data with other published data permits construction of a complete P-T projection and a sequence of isobars for the CaCO_3-MgCO_3 join for pressures between 5 and 30 kb. The phase relations for this join provide part of the essential framework of the model peridotite system CaO-MgO-SiO_8-CO_2-H_2O, which has particular application to the origin of carbonatitic and kimberlitic magmas. In light of the accumulating evidence for CO_2 in various forms within the upper mantle and of its effect on magmatic processes, analysis of the melting relations in this system is of considerable importance.", "doi": "10.1016/0016-7037(75)90183-0", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1975-01", "series_number": "1", "volume": "39", "issue": "1", "pages": "35-53" }, { "id": "authors:9svyc-n0d84", "collection": "authors", "collection_id": "9svyc-n0d84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-092454228", "type": "article", "title": "Eutectic between wollastonite II and calcite contrasted with thermal barrier in MgO-SiO_2-CO_2 at 30 kilobars, with applications to kimberlite-carbonatite petrogenesis", "author": [ { "family_name": "Huang", "given_name": "Wuu-Liang", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "In the join CaCO_3-CaSiO_3 at 30 kbars, calcite melts at 1615\u00b0C, wollastonite II at 1600\u00b0C, and a binary eutectic occurs at 1365\u00b0C with liquid composition 43 wt.% CaCO_3, 57 wt.% CaSiO_3. The eutectic liquid quenches to a glass with few quench crystals. In the join MgCO_3-MgSiO_3 at 30 kbars, magnesite melts at 1590\u00b0C, enstatite at 1837\u00b0C, and the fields for the primary crystallization of magnesite and enstatite are separated by a thermal barrier near 1900\u00b0C for the melting of forsterite in the presence of CO_2. Only about 10 wt.% MgSiO_3 dissolves in the carbonate liquid. These data, are considered together with incomplete results for joins CaMgSi2O6-CaMg(CO_3)_2, CaMgSi_2O_6-MgCO_3, CaMgSi_2O_6-CaCO_3, and other published data in the system CaO-MgO-SiO_2-CO_2. A thermal barrier separates the silicate and carbonate liquids in MgO-SiO_2-CO_2 but, in the quaternary system, silicate liquids with dissolved CO_2 can follow fractionation paths around the forsterite field to the fields for the primary crystallization of carbonates. This suggests that fractional crystallization of CO_2-bearing ultrabasic magma at 100 km depth can produce residual carbonatite magma.", "doi": "10.1016/0012-821X(74)90109-5", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1974-12", "series_number": "2", "volume": "24", "issue": "2", "pages": "305-310" }, { "id": "authors:6gam2-p6h52", "collection": "authors", "collection_id": "6gam2-p6h52", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-133540380", "type": "article", "title": "Melting Relations of Brown-Hornblende Mylonite from St. Paul's Rocks under Water-Saturated and Water-Undersaturated Conditions to 30 Kilobars", "author": [ { "family_name": "Millhollen", "given_name": "G. L.", "clpid": "Millhollen-G-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Crystalline brown-hornblende mylonite, with a composition similar to some basanites and nephelin-ites, was crushed and reacted with excess water and with no water added (about 2% water present) in sealed platinum capsules in a piston-cylinder apparatus from 10-30 kb. The solidus with excess water, and liquidus curves for excess water and for 2% water, are presented, together with stability limits (within 50\u00b0C brackets) in the melting intervals for amphibole, plagioclase, clinopyroxene, garnet, olivine, rutile, nepheline, and zoisite. With increasing water content and consequent decreasing liquidus temperature on the water-undersaturated liquidus surface, the number of liquidus and near-liquidus minerals increases, the field of olivine extends to higher pressures, and garnet becomes stabilized at pressures above 20 kb. Orthopyroxene was not found. Amphibole is stable at the liquidus between 10 and 21 kb with excess water at 1,075\u00b0C, and between 10 and 16 kb with 2% water at 1,175\u00b0C. These results combined with previous interpretations are consistent with the following tentative petrogenetic history for St. Paul's Rocks. A water-undersaturated olivine-basanite magma rose from a depth of about 100 km at a temperature of 1,200-1,300\u00b0C, and differentiated until it reached a depth somewhere between 45-70 km, where the magma had reached the composition of brown-hornblende mylonite. At a temperature between 1,050\u00b0C and 1,000\u00b0C amphibole was the dominant mineral being precipitated. Exsolution of water from the magma became fixed in the mantle peridotite as amphibole, and locally may have caused incipient melting of the peridotite. This process may have initiated upward movement of the heterogeneous assemblage of peridotite and largely crystallized basanite magma, which rose as a near-solid diapiric intrusion with temperature possibly remaining as high as 1,000\u00b0C up to 7 km deep, where intense mylonitization began during the final ascent and shallow emplacement.", "doi": "10.1086/628008", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1974-09", "series_number": "5", "volume": "82", "issue": "5", "pages": "589-606" }, { "id": "authors:r40kc-h0w96", "collection": "authors", "collection_id": "r40kc-h0w96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-143010090", "type": "article", "title": "Electron microprobe measurement of pyroxenes coexisting with H_2O-undersaturated liquid in the join CaMgSi_2O_6-Mg_2Si_2O_6-H_2O at 30 kilobars, with applications to geothermometry", "author": [ { "family_name": "Nehru", "given_name": "Cherukupalli E.", "clpid": "Nehru-C-E" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mixtures of synthetic crystalline enstatite and diopside were reacted with small water contents in sealed capsules in piston-cylinder apparatus at 30 kb between 1000\u00b0 C and 1700\u00b0 C. The compositions of coexisting enstatite and diopside solid solutions were measured with an ARL-EMX electron microprobe between 1000\u00b0 C and 1500\u00b0 C. Between 1100\u00b0 C and 1500\u00b0 C the pyroxenes coexisted with H_2O-undersaturated liquid which quenched to inhomogeneous pyroxene crystals. The presence of liquid facilitated growth of pyroxene crystals suitable for microprobe determinations. The solvus of Davis and Boyd (1966) is generally used in geothermometry; our enstatite solvus limb is a few mol-% richer in Mg_2Si_2O_6 in the temperature range 1000\u20131400\u00b0 C; our diopside solvus limb is a few mol-% richer in Mg_2Si_2O_6 below 1100\u00b0C, in close agreement between 1100\u00b0 C and 1200\u00b0 C, but richer in CaMgSi_2O_6 between 1200\u00b0 C and 1500\u00b0 C. Estimated equilibration temperatures for a diopside with composition 78.7% Di is 1300\u00b0 C according to our results compared with 1210\u00b0 C for the Davis and Boyd solvus.", "doi": "10.1007/BF00383357", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1974-09", "series_number": "3", "volume": "48", "issue": "3", "pages": "221-228" }, { "id": "authors:m74k1-fk591", "collection": "authors", "collection_id": "m74k1-fk591", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-132253116", "type": "article", "title": "Melting Interval of Peridotite with 5.7 per Cent Water to 30 Kilobars", "author": [ { "family_name": "Millhollen", "given_name": "G. L.", "clpid": "Millhollen-G-L" }, { "family_name": "Irving", "given_name": "A. J.", "clpid": "Irving-A-J" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Crystalline pargasite-rich spinel peridotite mylonite from St. Paul's Rocks containing 5.7% water bound in hydrous minerals was reacted in sealed platinum capsules in a piston-cylinder apparatus from 10 - 30 kb. At 10 kb the subsolidus assemblage is amphibole, olivine, orthopyroxene, clinopyroxene and spinel, an amphibole lherzolite; with increasing pressure garnet appears at 18 kb, spinel and amphibole disappear at about 25 kb; the resulting high pressure assemblage is that of a garnet lherzolite. The solidus was located in the presence of water-rich vapor, but vapor dissolves completely in the liquid at higher temperatures, and the liquid becomes water-undersaturated. Stability limits in the melting interval were determined for amphibole, garnet, spinel, clinopyroxene, orthopyroxene, and olivine (the liquidus mineral). The results are consistent with a published conclusion that St. Paul's Rocks is a diapiric, solid-state mantle intrusion initially mobilized at a depth between 45 km and 70 km near 1,000 - 1,050\u00b0C. An estimate of the solidus of peridotite with 0.2% water is presented and compared with other studies. At intermediate pressures this solidus is determined by the breakdown of amphibole. Discrepancies among results of the various studies probably arise at least in part from experimental problems involved in the complex systems.", "doi": "10.1086/628007", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1974-09", "series_number": "5", "volume": "82", "issue": "5", "pages": "575-587" }, { "id": "authors:7q8zm-km317", "collection": "authors", "collection_id": "7q8zm-km317", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160127-135553125", "type": "article", "title": "Melting relations of muscovite with quartz and sanidine in the K_2O-Al_2O_3-SiO_2-H_2O system to 30 kilobars and an outline of paragonite melting relations", "author": [ { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mixtures of synthetic muscovite with synthetic sanidine or natural\nquartz, with and without water, were reacted in piston-cylinder apparatus between\n10 and 35 kb; metastable corundum persisted in runs not seeded with sillimanite\nand kyanite. Phases produced include muscovite (Ms), KAlSi_3O_8 \u2022 H_2O (OrH), sanidine\n(Or), kyanite (Ky), sillimanite (Si), quartz (Qz), coesite (Ct), liquid (L), and\nvapor (V). Melting reactions determined include: (A) Ms + Qz \u21d4 Or + Ky + L,\n(B) Ms + Qz + V \u21d4 Ky + L, (C) Or + Qz + V \u21d4 L, and (D) OrH + Ct + V \u21d4 L.\nAt 30 kb, the vapor-absent melling reaction (A) is about 140\u00b0C higher than the\ncorresponding reaction (B) with excess vapor. Melting reactions (A) and (B) extrapolate\ndownward to meet the invariant point for the assemblage Ms + Or + Qz\n+ Si + L + V at 5.8 kb and 730\u00b0C, as defined by Storre and Karotke (1972). This\npoint lies just below melting reaction (C). This invariant point is the high pressure\nlimit for the subsolidus dehydration reaction: Ms + Qz \u21d4 Or + Si + V, and its\nposition facilitates selection from among the varied dehydration reactions previously\npublished. These results are combined with published results for melting reactions\nof muscovite without quartz, to provide a P-T projection of muscovite melting and\ndehydration reactions in the quaternary system. By analogy with the system K_2O-Al_2O_3-SiO_2-H_2O, a similar diagram for paragonite dehydration and melting reactions\nis obtained by combining published paragonite dehydration reactions with albite-quartz-water melting reactions. Comparison of these mineral stability grids with\npublished estimates of temperature distribution in subducted lithosphere slabs suggests\nthat muscovite in metamorphosed subducted sediment dissociates or melts at\nrelatively shallow depths, and it seems unlikely that muscovite can contribute water\nfor magmatic processes much beyond the arc-trench gap or influence chemical variations\nin lavas across an arc complex.", "doi": "10.2475/ajs.274.4.378", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1974-04", "series_number": "4", "volume": "274", "issue": "4", "pages": "378-395" }, { "id": "authors:yj6fn-p2k79", "collection": "authors", "collection_id": "yj6fn-p2k79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-131404158", "type": "article", "title": "Melting of Tonalite and Crystallization of Andesite Liquid with Excess Water to 30 Kilobars", "author": [ { "family_name": "Lambert", "given_name": "I. B.", "clpid": "Lambert-I-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Melting relations of a finely ground, crystalline tonalite with excess water have been studied at pressures between 10 kbar and 30 kbar, to a maximum temperature of 850\u00b0 C, and these data have been combined with previously published results at lower pressures and higher temperatures. The rock mineralogy of plagioclase, quartz, orthoclase, biotite, and amphibole begins to change just below 10 kbar, and by 30 kbar it is coesite, clinopyroxene, garnet, and kyanite. Runs were planned to determine the curve for the beginning of melting, but combining these with published results for andesites and andesite compositions between 1 kbar and 20 kbar permits delineation of the major features of the phase diagram through the melting interval. The solidus temperatures are: 1 kbar, 765\u00b0 C; 3 kbar, 690\u00b0 C; 10 kbar, 635\u00b0 C; 15 kbar, 628\u00b0 C; 20 kbar, 670\u00b0 C; 30 kbar, 735\u00b0 Orthoclase dissolves in the aqueous vapor phase between 3 kbar and 10 kbar. The quartz out-(coesite-out) phase boundary varies from about 30\u00b0 to 65\u00b0 above the solidus. The plagioclase-out phase boundary extends from about 2 kbar, 1,000\u00b0 to the solidus near 15.5 kbar, 630\u00b0 C. The liquidus phase is pyroxene up to about 10 kbar, 950\u00b0 C, and amphibole from there to about 18 kbar, 950\u00b0 C. Garnet is the liquidus phase at higher pressures. Biotite, stable to 800\u00b0-850\u00b0 C, reacts out between 15 kbar and 17.5 kbar, with the formation of garnet and kyanite. Garnet is reluctant to nucleate, but it appears at 15 kbar and is probably stable at considerably lower pressures. The amphibole reaction boundary extends from 18.5 kbar, 950\u00b0 to 21.5 kbar, 700\u00b0 C, but the equilibrium phase boundary could be lower by a few kilobars at 700\u00b0 according to some published work. No orthopyroxene was found in any runs. The experimental results have applications to high-grade metamorphism and the nature of the lower crust, the generation of batholiths, and the crystallization of andesite magmas rising from subduction zones.", "doi": "10.1086/627938", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1974-01", "series_number": "1", "volume": "82", "issue": "1", "pages": "88-97" }, { "id": "authors:ceb8n-m9r62", "collection": "authors", "collection_id": "ceb8n-m9r62", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-135647925", "type": "article", "title": "Melting relations of basalt-andesile-rhyolite-H_2O and a pelagic red clay at 30 kb", "author": [ { "family_name": "Stern", "given_name": "C. R.", "clpid": "Stern-C-R" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "An olivine basalt, a tonalite (andesite), a granite (rhyolite), and a red clay (pelagic sediment) were reacted, with known quantities of water in sealed noble metal capsules, in a piston-cylinder apparatus at 30 kb pressure. For the pelagic sediment, with H_2O+=7.8% and no additional water, the liquidus temperature is 1240\u00b0C, the primary phases are garnet and kyanite. The subsolidus phase assemblage is phengite mica+garnet+clinopyroxene+coesite+kyanite. With 5 wt.% water added, the liquidus temperatures and primary phases for the calc-alkaline rocks are 1280\u00b0-1180\u00b0-1080\u00b0, garnet+clinopyroxene, garnet, and quartz respectively. Garnet and clinopyroxene occur throughout the melting interval of the olivine tholeiite for all water contents. Garnet is joined by clinopyroxene 80\u00b0 below the andesite plus 5% H_2O liquidus, quartz is joined by clinopyroxene 180\u00b0 below the rhyolite plus 5% H_2O liquidus. The subsolidus phase assemblage is garnet+clinopyroxene+coesite+minor kyanite for all the calc-alkaline compositions. We conclude that calc-alkaline andesites and rhyolites are not equilibrium partial melting pruducts of subducted oceanic crust consisting of olivine tholeiite basalt and siliceous sediments. Partial melting in subduction zones produces broadly acid and intermediate liquids, but these liquids lie off the calc-alkaline basalt-andesite-rhyolite join and must undergo modification at lower pressures to produce calcalkaline magmas erupted in overlying island arcs.", "doi": "10.1007/BF00372609", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1973-12", "series_number": "4", "volume": "42", "issue": "4", "pages": "313-323" }, { "id": "authors:jt3zr-9bn80", "collection": "authors", "collection_id": "jt3zr-9bn80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-153534435", "type": "article", "title": "Melting relationships in CaO-CO_2 and MgO-CO_2 to 36 kilobars with comments on CO_2 in the mantle", "author": [ { "family_name": "Irving", "given_name": "A. J.", "clpid": "Irving-A-J" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The melting curves of CaCO_3 and MgCO_3 have been extended to pressures of 36 kb by experiments in piston-cylinder apparatus. At 30 kb, the melting temperatures of calcite and magnesite are 1610\u00b0C and 1585\u00b0C, respectively. New data for the magnesite dissociation reaction permit the location of an invariant point for the assemblage magnesite + periclase + liquid + vapor near 26 kb-1550\u00b0C. New data are also presented for the calcite-aragonite transition at 800\u00b0C, 950\u00b0C and 1100\u00b0C. At pressures above 36\u201350 kb, calcite and magnesite melt at temperatures lower than the solidus of dry mantle peridotite. Natural and experimental evidence suggests that carbon dioxide in the Earth's mantle could be present in a variety of forms: (a) a free vapor phase, (b) vapor dissolved in silicate magma, (c) crystalline carbonate, (d) carbonatite liquid, (e) carbon-bearing silicate analogs, or (f) carbonato-silicates (such as scapolite, spurrite, tilleyite, and related compounds).", "doi": "10.1016/0012-821X(73)90161-1", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1973-10", "series_number": "2", "volume": "20", "issue": "2", "pages": "220-225" }, { "id": "authors:byjdz-1hd19", "collection": "authors", "collection_id": "byjdz-1hd19", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-142035668", "type": "article", "title": "Liquid immiscibility in the join NaAlSi_3O_8-CaAl_2Si_2O_8-Na_2CO_3-H_2O", "author": [ { "family_name": "van Groos", "given_name": "A. F. Koster", "clpid": "van-Groos-A-F-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The phase relationships in the six component system NaAlSi_3O_8-\nCaAl_2Si_2O_8-Na_2CO_3-H_2O were determined between 650\u00b0 and 950\u00b0C and 1 kb pressure\nalong the joins Ab_(80)An_(20)-Na_2CO_3 and Ab_(50)An_(50)-Na_2CO_3, both with 10 percent H_2O\npresent. The phase relationships are complex. Crystalline phases encountered were\nplagioclase, nepheline, noselite, cancrinite, wollastonite, sodium carbonate, and sodium\ncalcium carbonate. The solidus was intersected at minimally 695\u00b0C.\nThe most important feature is the presence of a two-liquid field above 750\u00b0C,\nseparating a carbonate-poor silicate liquid and a silicate-poor carbonate liquid. Electron\nmicroprobe analyses of the quenched silicate liquid and atomic absorption data for\nthe quenched carbonate liquid show that the silicate liquid is peralkaline and strongly\nundersaturated in silica and that the coexisting carbonate liquid is strongly enriched\nin calcium.\nA third fluid phase present with these two liquids is an aqueous vapor phase\nenriched with sodium silicate and CO_2.\nIt is concluded that in this system three fluid phases coexist that correlate well\nwith the natural occurring undersaturated alkalic urtite-ijolite-melteigite rock series,\nthe carbonatites, and the associated metasomatic fenites of the carbonatite-alkalic rock\ncomplexes.", "doi": "10.2475/ajs.273.6.465", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1973-06", "series_number": "6", "volume": "273", "issue": "6", "pages": "465-487" }, { "id": "authors:58zcp-hcw34", "collection": "authors", "collection_id": "58zcp-hcw34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160127-140834301", "type": "article", "title": "Melting relations of muscovite to 30 kilobars in the system KAlSi_3O_8-Al_2O_3-H_2O", "author": [ { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mixtures of synthetic muscovite, sanidine, and muscovite-sanidine, with\nor without water, were reacted in piston-cylinder apparatus between 10 and 35 kb.\nPhases produced include muscovite(Ms), KAlSi_3O_8H_2O(OrH), sanidine(Or), corundum(Co), liquid(L), and vapor(V). Melting reactions determined are: (a) Ms \u21d4 Or +\nCo + L, (b) Ms + V \u21d4 Co + L, (c) Ms + Or + V \u21d4 L, (cl) Or + V\u21d4 L.\nTemperatures of univariant curves are, at 15 kb, (a) 885\u00b0 (b) 855\u00b0 (c) 780\u00b0 (d) 795\u00b0;\nand at 30 kb, (a) 1010\u00b0 (b) 935 \u00b0 (c) 720\u00b0 (d) 755 \u00b0. At 30 kb the vapor-absent melting\nreaction (a) is 75\u00b0 higher than the corresponding reaction (b) with excess vapor.\nExtrapolation of these melting reactions downward places close limits on the invariant\npoint at 9.5 kb and 825\u00b0C for the coexistence of Ms + Or + Co + L + V and defines\nthe high pressure limits for reactions Ms \u21d4Or + Co + V, and Or + Co +\nV \u21d4 L. This facilitates selection from among the varied muscovite dehydration reaction\ncurves previously published.\nComparison of the muscovite stability range with published estimates of temperature\ndistribution in subducted lithosphere slabs suggests that muscovite in subducted\nsediments neither contributes water for magmatic processes beyond the arc-trench gap\nnor influences the chemical variations in lavas across an arc complex. It dissociates\nor melts at shallower depths.", "doi": "10.2475/ajs.273.5.415", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1973-05", "series_number": "5", "volume": "273", "issue": "5", "pages": "415-427" }, { "id": "authors:x6snf-25h91", "collection": "authors", "collection_id": "x6snf-25h91", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-094819995", "type": "article", "title": "Experimental petrology and global tectonics \u2014 A preview", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The new global tectonics provides a convenient tectonic framework for igneous and metamorphic petrology in the five environments: oceanic plates, continental plates, divergent plate boundaries, convergent plate boundaries, and transform plate boundaries. Models have been developed involving: \n1.\n(1)the generation of oceanic crust from basalt and serpentinite at mid-ocean ridges;\n2.\n(2) metamorphism and hydration of the crust to yield greenschist, hornblende-gabbro, or amphibolite;\n3.\n(3) lateral transport of the crust by sea-floor spreading;\n4.\n(4) subduction of the crust at convergent plate boundaries, with\n5.\n(5) blueschist metamorphism associated with oceanic trenches;\n6.\n(6) transformation of the subducted crust into quartz-eclogite;\n7.\n(7) partial fusion of amphibolite or quartz eclogite and subducted oceanic sediments to yield the calc-alkaline magma series; and\n8.\n(8) the emplacement of batholiths in high-temperature metamorphic rocks at the base of the island or continental margin arc complexes. We have assumed starting materials, beginning with mantle peridotite beneath the oceanic rises, and a series of processes involving partial fusion of mantle peridotite, crystallization, hydration, solid-solid phase transformations, dehydration, and partial fusion of the diverse materials in the subducted oceanic crust. Experimental petrology makes possible the testing of models and determination of the pressures and temperatures for the operation of these processes. Water is an important component. For processes at the oceanic ridges we do not know how much water is juvenile and how much is introduced from the ocean. The hydrated oceanic rocks are subducted and then dehydrated, but there remains some uncertainty about whether this water is carried deep enough to participate in the generation of calc-alkaline magmas, and possibly juvenile water is involved. The combined approaches of geophysics, geochemistry, geology, and experimental petrology within the framework of the new global tectonics are providing new insights into the differentiation of the earth.", "doi": "10.1016/0040-1951(73)90002-4", "issn": "0040-1951", "publisher": "Elsevier", "publication": "Tectonophysics", "publication_date": "1973-04", "series_number": "3", "volume": "17", "issue": "3", "pages": "189-209" }, { "id": "authors:rrhpb-v5p05", "collection": "authors", "collection_id": "rrhpb-v5p05", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-135812177", "type": "article", "title": "Presentation of the Mineralogical Society of America Award for 1972 to Arthur L. Boettcher", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "It is a real privilege for me to introduce a friend\nand colleague for the Mineralogical Society of America\nAward. Dr. Arthur L. Boettcher earned this\naward at least in part because he has developed the\nart of hard work and long hours to a high degree.\nThis is well known to his students. Because he moves\nso rapidly between office and laboratory, they have\nchristened him \"Art the Dart.\" I shall try to give\nyou some idea of how he acquired such a distinguished\ntitle without being born into the ruling class.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1973-03", "series_number": "3-4", "volume": "58", "issue": "3-4", "pages": "355-356" }, { "id": "authors:se8kt-3d562", "collection": "authors", "collection_id": "se8kt-3d562", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-134034204", "type": "article", "title": "Melting relations of muscovite-granite to 35 kbar as a model for fusion of metamorphosed subducted oceanic sediments", "author": [ { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Muscovite-granite was reacted in cold-seal pressure vessels at 2 kbar and in pistoncylinder apparatus between 10 and 35 kbar, with just 0.6 weight per cent water structurally bound in 14 modal per cent muscovite, and with additional water contents varying to 50 weight per cent. Phase relationships are presented through the melting interval with excess water, and with no free water added. Selected reactions above 10 kbars have been successfully reversed. An isobar at 15 kbar shows the effect of varying water contents on the mineral phase boundaries for vapor-present and vapor-absent conditions. For the dry rock, temperatures for the solidus and liquidas (quartz-out) curves, respectively, are 10 kbar-760\u00b0 C, 1160\u00b0 C; 15 kbar-810\u00b0 C, 1220\u00b0 C; 25 kbar-880\u00b0 C; 1340\u00b0 C; 35 kbar-1040\u00b0 C, 1460\u00b0 C. The solidus curve corresponds to the melting of muscovite + quartz. With water vapor present, the solidus is considerably lower, 15 kbar-610\u00b0 C, 25 kbar-665\u00b0 C. Water solubility in the liquid at 15 kbar is 24\u00b13 weight per cent. Maximum temperatures for quartz and feldspars in the vapor-absent region decrease considerably with increasing water content. Temperatures for the quartz-out curve at 15 kbars are 0.6 % H_2O-1230\u00b0 C; 24 % H_2O-760\u00b0 C. At 15 kbars for low water contents, water-undersaturated liquid coexists with quartz and feldspars through hundreds of degrees. Subducted pelagic sediments which metamorphosed to muscovitebearing quartzo-feldspathic rocks would undergo two episodes of melting, beginning at different depths: (1) the first liquid dissolves all pore fluid, and transports it away when it escapes from the crystalline host, (2) reaction of muscovite yields a second liquid, with less dissolved water. According to two published thermal models for a lithosphere slab dipping at 45\u00b0, the depths would be (a) 60 km and 92 km, or (b) 17 km and 21 km. Magmas generated by partial fusion in subducted oceanic crust are cooler than the overlying crustal layers and the mantle above the slab by as much as 200\u00b0 C to 300\u00b0 C. This must lead to intrusion of relatively cool magma into hot rock. Consequent heating of the magma increases its prospects of reaching high levels in the upper mantle or crust before it solidifies by crossing the solidus curve.", "doi": "10.1007/BF00521643", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1973-03", "series_number": "1", "volume": "42", "issue": "1", "pages": "1-14" }, { "id": "authors:grvee-7dr51", "collection": "authors", "collection_id": "grvee-7dr51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-131122924", "type": "article", "title": "Muscovite dehydration and melting in deep crust and subducted oceanic sediments", "author": [ { "family_name": "Huang", "given_name": "W. L.", "clpid": "Huang-Wuu-Liang" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Mixtures of natural quartz and synthetic muscovite and sanidine, with and without free water, were reacted in piston-cylinder apparatus between 10 and 35 kb. Extrapolation of experimentally determined melting curves defines an invariant point for the assemblage muscovite + sanidine + corundum + liquid + vapor at 9.5 kb and 825\u00b0C, and one for the same assemblage with quartz at 5.8 kb and 730\u00b0C. These two points define the high pressure limit for the subsolidus dehydration reactions of muscovite and of muscovite + quartz, which facilitates selection among the varied muscovite dehydration curves previously published. Comparison of published estimates of temperature distribution of subducted lithosphere slabs with muscovite stability ranges indicates that muscovite in subducted oceanic sediments would probably be dehydrated or melted before reaching a depth of 30 km, with a maximum possible depth of 100 km. This suggests that although muscovite could possibly be involved in magma generation at volcanic fronts, it neither contributes water for magmatic processes much beyond Dickinson's arc-trench gap, nor influences the chemical variation in calc-alkaline lavas across arc complexes and in plutonic rocks across batholiths.", "doi": "10.1016/0012-821X(73)90045-9", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1973-02", "series_number": "1", "volume": "18", "issue": "1", "pages": "133-136" }, { "id": "authors:b4x2k-ywj29", "collection": "authors", "collection_id": "b4x2k-ywj29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-134940775", "type": "article", "title": "Water-saturated and undersaturated melting relations of a granite to 35 kilobars", "author": [ { "family_name": "Stern", "given_name": "C. R.", "clpid": "Stern-C-R" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Biotite granite from the Sierra Nevada batholith was reacted, with known water contents in sealed platinum capsules, in a piston-cylinder apparatus between 10 and 35 kb. With the liquid just over-saturated with respect to water, temperatures for solidus and liquidus (quartz/coesite-out curve), respectively, are: 2 kb, 680\u00b0C, 715\u00b0C; 10 kb, 620\u00b0C, 725\u00b0C; 25 kb, 655\u00b0C, 800\u00b0C; 35 kb, 700\u00b0C, 850\u00b0C. The temperature interval is 35\u00b0C at 2 kb, 105\u00b0C at 10 kb, and 150\u00b0C at 35 kb, indicating that granite departs from a eutectic composition at depths greater than about 40\u201350 km. We conclude that crystal-liquid equilibria are not likely to yield primary rhyolite or granite magmas by partial fusion of oceanic crust in subduction zones. The solubility of water in granite liquids, in wt%, is 22.5 \u00b1 2.5 at 25 kb and 810\u00b0C and 27 \u00b1 2.5 at 35 kb and 850\u00b0C. These results indicate that a miscibility gap persists between water-saturated silicate magmas and aqueous vapor phase at least to pressures corresponding to 100 km depth in the mantle. The formation of kyanite near the liquidus of water over-saturated granite indicates that the aqueous vapor phase is enriched in alkalis and possibly silica, relative to the condensed phases.", "doi": "10.1016/0012-821X(73)90052-6", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1973-02", "series_number": "1", "volume": "18", "issue": "1", "pages": "163-167" }, { "id": "authors:dkzhs-mzw75", "collection": "authors", "collection_id": "dkzhs-mzw75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-133307803", "type": "article", "title": "Absorption of iron by platinum capsules in high pressure rock melting experiments", "author": [ { "family_name": "Merrill", "given_name": "Russel B.", "clpid": "Merrill-R-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Samples of hornblende eclogite (olivine basanite composition), containing 0.38 wt percent\nH_2O bound in amphibole, were sealed in Pt capsules, held above the liquidus at 1250\u00b0C, 10\nkbar, in 1/2-inch piston-cylinder apparatus for various time periods, and then sectioned for\nmicroprobe analyses. The resultant liquids lost about half of their initial 14 wt percent FeO\n(total Fe as FeO) to the Pt capsule during an experiment of only thirty minutes duration, and\nlost 97 percent during a run lasting four hours. This rate is significantly greater than rates of\niron loss reported previously, and can affect significantly the interpretation of experimental\nresults in high temperature studies of basaltic and periodotitic compositions.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1973-01", "series_number": "1-2", "volume": "58", "issue": "1-2", "pages": "16-20" }, { "id": "authors:6cyp1-hfp21", "collection": "authors", "collection_id": "6cyp1-hfp21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160210-091155465", "type": "article", "title": "Melting of Gabbro (Quartz Eclogite) with Excess Water to 35 Kilobars, with Geological Applications", "author": [ { "family_name": "Lambert", "given_name": "I. B.", "clpid": "Lambert-I-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Crystalline, fine-grained, high-alumina olivine tholeiite with excess water was reacted in sealed platinum capsules in piston-cylinder apparatus between 10 and 35 kbar pressure. Runs were planned to determine the curve for the beginning of melting, but combining these with published results at lower pressures permitted delineation of the major features of the phase diagram through the melting interval. Amphibolite melts below 10 kbar; quartz eclogite melts above 25 kbar; between them is a melting interval dominated by the breakdown of amphibole and formation of garnet and jadeitic pyroxene. The results introduce two features for geological applications. The solidus changes slope at about 13.5 kbar; the amphibole maximum-stability curve changes slope in the interval 12.5-15 kbar to such an extent that the amphibole stability field is more restricted at high pressures than anticipated from previous studies. With free water, eclogite is Stable only at depths greater than about 70 km, and amphibolite is Stable in the deep crust. Amphibolite crust thickened in the depth range 40-60 km with aqueous pore fluid melts, forming a liquid enriched in silica and albitic plagioclase; this is a potential source of water-undersaturated liquids for batholiths. The upper boundary of the mantle low-velocity zone could be the boundary between rocks with interstitial amphibole and those with interstitial hydrous silicate liquid. In oceanic crust forming the upper part of a subducted lithosphere slab, it appears that most hydrous minerals dehydrate or melt before they reach 100 km depth. If so, dehydration of subducted oceanic crust does not supply water for andesitic magmatism beyond the arc-trench gap, nor contribute to the chemical variations recorded in andesites across arc complexes (K_2O, K/Rb).", "doi": "10.1086/627795", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1972-11", "series_number": "6", "volume": "80", "issue": "6", "pages": "693-708" }, { "id": "authors:gsjhq-6q477", "collection": "authors", "collection_id": "gsjhq-6q477", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-124246553", "type": "article", "title": "Dehydration reaction of titanoclinohumite: Reconnaissance to 30 kilobars", "author": [ { "family_name": "Merrill", "given_name": "R. B.", "clpid": "Merrill-R-B" }, { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Natural titanoclinohumite was reacted in Pt capsules, using open air furnaces, hydrothermal and piston-cylinder apparatus. The reaction was not reversed, nor was it defined in terms of mineral products. Dehydration begins with the formation of forsterite at 950\u00b0C at 1 atm., 1150\u00b0C at 10 kbar, 1190\u00b0C at 20 kbar, and 1170\u00b0C at 30 kbar. Therefore, titanoclinohumite can exist as a hydrous mineral in the upper mantle. The reconnaissance results are consistent with the conclusion that titanoclinohumite coexisted with chrome-pyrope and olivine at the mantle source of the Moses Rock kimberlite; they make it unlikely that titanoclinohumite supplied water for the emplacement and eruption of the Moses Rock kimberlite through dehydration above 150 km but they do not preclude the possibility at greater depths.", "doi": "10.1016/0012-821X(72)90017-9", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "1972-03", "series_number": "2", "volume": "14", "issue": "2", "pages": "259-262" }, { "id": "authors:w442e-sv063", "collection": "authors", "collection_id": "w442e-sv063", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160308-084310100", "type": "article", "title": "Earthquakes and continental drift", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "[no abstract]", "issn": "0041-9508", "publisher": "University of Chicago", "publication": "University of Chicago Magazine", "publication_date": "1972", "volume": "64", "pages": "12-29" }, { "id": "authors:9eq7h-ntb22", "collection": "authors", "collection_id": "9eq7h-ntb22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160127-144713306", "type": "article", "title": "Melting relations of NaAlSi_3O_8 to 30 Kb in the presence of H_2O:CO_2 = 50:50 vapor", "author": [ { "family_name": "Millhollen", "given_name": "G. L.", "clpid": "Millhollen-G-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Burnham", "given_name": "C. Wayne", "clpid": "Burnham-C-W" } ], "abstract": "Synthetic albite was reacted with oxalic acid dihydrate under oxidizing\nconditions in an internally-heated pressure vessel from 1 to 4 kb and in a piston-cylinder\napparatus from 10 to 30 kb. Breakdown of the oxalic acid in subsolidus runs\nproduced a vapor with H_2O:CO_2 = 50:50 in moles (X^v_(H_2O) = 0.5, neglecting solubility\nof solids in the vapor). The curve determined for the beginning of melting under these\nconditions defines a contour on the divariant solidus surface for the system NaAlSi_3O_8-H_2O-CO_2 for X^v_(H_2O) = 0.5, between the published limits for X^v_(H_2O) = 1.0 and X^v_(H_2O) = O.\nAddition of 50 mole percent of relatively insoluble CO_2 to NaAlSi_3O_8-H_2O at 15 kb\ntotal pressure raises the solidus temperature from 660\u00b0 to 830\u00b0C. The results give no\nindication of increased solubility of CO_2 in NaAlSi_3O_8 liquids at pressures above 15 kb,\nin contrast with published results for a basalt liquid.", "doi": "10.2475/ajs.271.5.473", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1971-12", "series_number": "5", "volume": "271", "issue": "5", "pages": "473-480" }, { "id": "authors:6g6v1-jn562", "collection": "authors", "collection_id": "6g6v1-jn562", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-111825527", "type": "article", "title": "Rock-water systems, with special reference to the water-deficient region", "author": [ { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The four types of subsolidus assemblages in silicate-water systems are:\nType I, water-absent; assemblage of anhydrous minerals with no vapor phase. Type\nII, water-deficient and vapor-absent; assemblage of minerals including hydrous minerals,\nbut with no vapor phase. Type III, water-deficient and vapor-present; an assemblage\nof minerals, with or without hydrous minerals, with a vapor phase; there is\ninsufficient water present to saturate the liquid when the crystalline assemblage is\ncompletely melted at the existing pressure. Type IV, water-excess; an assemblage of\nminerals and vapor with at least enough water to saturate the liquid when the crystalline\nassemblage is completely melted at the existing pressure. Water-deficient systems\nof types II and III are significant for magma generation and crystallization; there are\nfew experimental results. Water-deficient phase relationships can be estimated by\ninterpolation between available experimental data for systems of types I and IV.\nMantle magmas are generated in type I, II, or III systems. The first liquid produced\nin type III systems is H_20-saturated, and the first liquid in type II systems\nis H_2O-undersaturated. It appears that the normal product of partial fusion of many\ncontinental crustal rocks is a H_2O-undersaturated granite liquid in a crystal mush,\nand that liquids of intermediate composition are not generated because temperatures\nrequired are too high. Phase relationships are depicted for granodiorite in a pressure-temperature-\nwater diagram.", "doi": "10.2475/ajs.271.3.252", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1971-10-01", "series_number": "3", "volume": "271", "issue": "3", "pages": "252-277" }, { "id": "authors:4qwt7-8x256", "collection": "authors", "collection_id": "4qwt7-8x256", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160211-135512563", "type": "article", "title": "Experimental Studies on Rocks from the Deboullie Stock, Northern Maine, including Melting Relations in the Water-Deficient Environment", "author": [ { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Two syenites, a syenodiorite, and a granodiorite from the Deboullie Stock were melted in the presence of excess water. In addition, the two syenites-similar in chemical composition but contrasting in the modal amounts of hydrous minerals-were melted with a series of water contents from 0 to 10 wt %. Results from the water-excess experiments are similar to those for other calc-alkaline rocks with the following differences: (1) a clinopyroxene was present through the melting interval for the syenites and syenodiorite and for only part of the interval for granodiorite; (2) at 2 kbar, the quartz-absent syenodiorite began melting at 775\u00b0C while the other three rocks began melting below 700\u00b0C; and (3) two feldspars from the syenites coexisted through an interval of 100\u00b0-150\u00b0C above the solidus at 2 kbar. Results from the water-deficient runs were difficult to interpret because of disequilibrium within runs lasting 180-330 days. In the vapor-absent region, quartz and feldspars coexist with liquid at temperatures much higher than in the vapor-present experiments. Their upper stability limits are strongly dependent on the water content increasing by about 100\u00b0 C for 1 wt % decrease in water content.", "doi": "10.1086/627675", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1971-09", "series_number": "5", "volume": "79", "issue": "5", "pages": "549-571" }, { "id": "authors:9gmyz-dmq44", "collection": "authors", "collection_id": "9gmyz-dmq44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-131630125", "type": "article", "title": "Experimental Study of the Composition Join NaAlSiO_4-CaCO_3-H_2O and the Genesis of Alkalic Rock--Carbonatite Complexes", "author": [ { "family_name": "Watkinson", "given_name": "David H.", "clpid": "Watkinson-D-H" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase equilibrium studies have been carried out on the composition join NaAlSiO_4-CaCO_3-H_2O with 25 wt per cent H_2O at 1 kb pressure in the temperature range 600\u2013960 \u00b0C. Liquid, in equilibrium with crystalline phases and a sodic, aqueous vapor phase persists across the join down to temperatures of about 600 \u00b0C. Fractional crystallization of a carbonated nepheline-rich liquid in equilibrium with vapor is capable of generating successively the crystalline assemblages (1) nepheline, (2) melilite+nepheline, (3) hydroxyha\u00fcyne+melilite, (4) cancrinite+melilite, and (5) calcite+cancrinite+melilite. Late-stage liquid fractions are rich in CaCO3, whereas the vapor phase is enriched in Na. The experimental assemblages are strikingly similar to rocks in alkalic rock-carbonatite complexes in general and in the Oka, Quebec, complex in particular. The succession of assemblages at Oka and at other melilite rock-bearing complexes may be interpreted as the products of fractionation of a carbonated nephelinite magma by analogy with the experimental results. The sodium-bearing vapor phase of the experiments may be analogous to the fenitizing agent of some carbonatite complexes.", "doi": "10.1093/petrology/12.2.357", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1971-06", "series_number": "2", "volume": "12", "issue": "2", "pages": "357-378" }, { "id": "authors:1q1tq-v8476", "collection": "authors", "collection_id": "1q1tq-v8476", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151106-105623186", "type": "article", "title": "Petrologic aspects of plate tectonics", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The concept of plate tectonics has developed during the past four years from the hypotheses of continental drift and sea-floor spreading, supported by a variety of evidence from paleomagnetism, geochronology, and marine geology and geophysics. A series of four contiguous papers in the March 1968 issue of the Journal of Geophysical Research correlated on a global scale the linear magnetic anomalies, which are parallel to and bilaterally symmetrical about the oceanic ridge system, with the polarity reversals of the earth's magnetic field imprinted on new oceanic crust as it was generated at the oceanic ridge crests [Pitman et al., 1968; Dickson et al., 1968; Le Pichon and Heirtzler, 1968; Heirtzler et al., 1968]. In 1967 and 1968, four major papers introduced plate tectonics: the earth's surface is considered to be made up of a few rigid crustal plates or blocks in motion relative to each other [McKenzie and Parker, 1967; Morgan, 1968; Le Pichon, 1968; Isacks et al., 1968].", "doi": "10.1029/EO052i005pIU062", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1971-05", "series_number": "5", "volume": "52", "issue": "5", "pages": "62-66" }, { "id": "authors:4rtcv-m8482", "collection": "authors", "collection_id": "4rtcv-m8482", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151106-111057908", "type": "article", "title": "Melting relations", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The process of magma generation with subsequent uprise and intrusion or extrusion of magma is one of the fundamental processes in the evolution of the earth. Rheological and other physical properties change markedly wherever and whenever partial melting occurs. The melting relations of minerals and rocks can now be measured in the laboratory to pressures corresponding to depths of more than 250 km. The measurements provide limits for temperatures within the earth and a basis for extrapolation to greater depths. This report outlines experimental results for the melting of elements, minerals, and rocks under various conditions, in a dry state or in the presence of water and other volatile components. There is overlap with reports on experimental petrology in another section, but it is reduced to a minimum by limiting this review to melting curves and properties, without attention to the more detailed aspects of petrogenesis.", "doi": "10.1029/EO052i005pIU153", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1971-05", "series_number": "5", "volume": "52", "issue": "5", "pages": "153-156" }, { "id": "authors:tgjgk-3gj82", "collection": "authors", "collection_id": "tgjgk-3gj82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-094734057", "type": "article", "title": "Experimental Studies of Igneous Rock Series: The Kungnat Syenite Complex of Southwest Greenland", "author": [ { "family_name": "Mc Dowell", "given_name": "S. D.", "clpid": "Mc-Dowell-S-D" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The melting relationships of five rocks from the alkaline igneous complex at Kungnat, southwest Greenland, were determined in the presence of 25 wt percent water at pressures to 3 kbar. Run durations varied between 4 and 27 days. The rocks studied are samples from the two layered syenite bodies comprising the complex and from late granite sheets intruding the syenites. The experimental results are consistent with the petrogenetic hypothesis that there were four magma portions tapped from an already differentiated magma chamber, with each subsequently differentiating along independent paths after emplacement. They suggest that the magmas were emplaced at low water pressures at temperatures about 1,000\u00b0C, with water pressure reaching about 1.5 kbar in the stages of crystallization when amphibole was precipitated as reaction rims around pyroxenes. The phase relationships in the syenites differ from those previously reported for calc-alkaline plutonic series from tonalite to granite mainly by (1) the wide temperature interval for crystallization of two feldspars (feldspars did not reach equilibrium compositions) and (2) the absence of amphibole through the melting interval because of the low dissociation temperature of the amphibole. All rocks investigated are at least 75 percent melted at temperatures 100\u00b0C above the solidus.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1971-03", "series_number": "2", "volume": "79", "issue": "2", "pages": "173-194" }, { "id": "authors:ds37s-tb525", "collection": "authors", "collection_id": "ds37s-tb525", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141107-085959135", "type": "article", "title": "Role of water in magma generation and initiation of diapiric uprise in the mantle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The content and distribution of water is a critical factor in determining mantle properties, especially in the low-velocity and Benioff zones. Estimated temperature distributions vary widely, depending on assumptions regarding the relative significance for heat transfer of conduction, radiation, and convection. Comparison of estimated geotherms with known or inferred phase relationships in the system peridotite-eclogite-water provides information about the possible physical state of the mantle at various depths for comparison with geophysical measurements. Water is stabilized in minerals such as amphibole and phlogopite in the upper mantle; at greater depths, it may exist as intergranular fluid probably adsorbed on mineral surfaces, or it is dissolved in interstitial silicate magma. The most satisfactory explanation for the low-velocity zone involves incipient melting due to traces of water. Water rising from the deep mantle in preferred zones would augment the interstitial silicate magma at the base of the low-velocity zone, initiating the diapiric uprise necessary for basaltic magma generation. A petrological model for the suboceanic mantle suggests that a lens of gabbro-rich material may account for the gravity anomaly and seismic refraction measurements at mid-oceanic ridges. A petrological model for the area beneath island arcs suggests that the seismic low-velocity zone should not be continuous across it. Magma may be generated beneath island arcs by partial fusion of down-going oceanic crust by frictional heating, by migration of water from the lithosphere into overlying mantle, or by diapiric uprise of material from the downgoing lithosphere. Diapiric uprise could be initiated by influx of water into the layer including; the mantle-upper lithosphere boundary over a down-going slab. The composition of the liquid generated depends on many variables, including the water content and the stability of hydrous minerals. Magma generation may depend on the regime of water, rising from the deep mantle in preferred zones and carried down with the lithosphere in Benioff zones.", "doi": "10.1029/JB076i005p01328", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research", "publication_date": "1971-02-10", "series_number": "5", "volume": "76", "issue": "5", "pages": "1328-1338" }, { "id": "authors:5j4dk-x7h84", "collection": "authors", "collection_id": "5j4dk-x7h84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-103830305", "type": "article", "title": "Melting Reactions in the System NaAlSi_3O_8-KAlSi_3O_8-SiO_2-H_2O to 20 Kilobars Compared with Results for Other Feldspar-Quartz-H_2O and H_2O Systems", "author": [ { "family_name": "Merrill", "given_name": "R. B.", "clpid": "Merrill-R-B" }, { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Synthetic feldspar with composition Ab_(60)Or_(40) was crystallized from gel and a portion mixed with 10 wt percent natural quartz. These starting materials were reacted with excess water in sealed platinum capsules, using half-inch-diameter piston-cylinder apparatus. Univariant melting curves were located between 10 and 20 kbar pressure for the systems NaAlSi_3O_8(Ab)-KAlSi_3O_8(Or)-SiO_2(Qz)-H_2O and Ab-Or-H_2O. Points on the reaction curves are:\n(1) Ab_(ss)+Or_(ss)+Qz+V\u21d4L; 10 kbar at 615\u00b0 C, 15 kbar at 605 \u00b0C.\n(2) Ab_(ss)+Or_(ss)+V\u21d4L; 10 kbar at 655\u00b0C, 15 kbar at 615\u00b0 C, 16.75 kbar at 605 \u00b0C. (3) A reaction common to both systems, Or_(ss)+Jd+Qz+V\u21d4L (Jd is jadeite); 19.5 kbar at 630\u00b0 C.. These three reaction curves meet at an invariant point at 16.8 kbar and 605\u00b0 C. Reactions (1) and (2) represent the curves for the beginning of melting of granite and syenite, respectively. A review of previous results provides our best estimates for melting curves from 1 to 20 kbar (or higher) in these systems and additional systems Or-Qz-H_2O and CaAl_2Si_2O_8(An)-Qz-H_2O and rock-H_2O systems. Curves for the beginning of melting of major rock types in the presence of excess water have recently been extended to mantle pressures, and the influence of feldspar and quartz in granite, tonalite, syenite, and gabbro melting is evident to about 15 kbar, from comparison of the rock-H_2O curves with the feldspar-quartz-H_2O curves. The melting pattern changes above the pressure where plagioclase feldspar breaks down, and the slope (dP/dT) of the melting curves then becomes positive and roughly parallel with curves for dry systems. Data for excess-water systems are almost complete; these will provide guides for the study of water-deficient systems in the vapor-absent region, which is more relevant for problems of magma genesis and magma evolution.", "doi": "10.1086/627553", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1970-09", "series_number": "5", "volume": "78", "issue": "5", "pages": "558-569" }, { "id": "authors:3rwtm-z4q13", "collection": "authors", "collection_id": "3rwtm-z4q13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-122826913", "type": "article", "title": "Low-Velocity Zone of the Earth's Mantle: Incipient Melting Caused by Water", "author": [ { "family_name": "Lambert", "given_name": "Ian B.", "clpid": "Lambert-I-B" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental phase diagrams for the systems gabbro-water and peridotite-water indicate that, if there is any water in the upper mantle, then traces of hydrous interstitial silicate magma will be produced at depths corresponding to the beginning of the low-velocity zone. This explanation for the zone is more satisfactory than others proposed.", "doi": "10.1126/science.169.3947.764", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1970-08-21", "series_number": "3947", "volume": "169", "issue": "3947", "pages": "764-766" }, { "id": "authors:qjv92-2zs76", "collection": "authors", "collection_id": "qjv92-2zs76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160126-100216606", "type": "article", "title": "Phase equilibrium studies bearing on genetic links between alkaline and subalkaline magmas, with special reference to the limestone assimilation hypothesis", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" }, { "family_name": "Watkinson", "given_name": "David H.", "clpid": "Watkinson-D-H" } ], "abstract": "The limestone assimilation hypothesis for forming alkaline, magmas from subakaline\nmagmas is based on circumstantial petrological evidence. It requires (1) desilication,\n(2) alkali transfer by CO_2 and H_2O. Experimental results indicate that limestone assimilation\ncauses crystallization, and that the thermal barrier between granitic and feldspathoidal\nliquids persists in the presence of H_2O and CO_2 to high pressures. Desilication\nof SiO_2-oversaturated magmas remains an unlikely process. Results in silicate-salt-volatile\nsystems suggest that alkali transfer is only effective from liquids already enriched in\nalkalis. In general, experimental studies have failed to validate proposed genetic links\nbetween alkaline and subalkaline magmas through assimilation.", "issn": "0008-4476", "publisher": "Mineralogical Association of Canada", "publication": "Canadian Mineralogist", "publication_date": "1970-08", "series_number": "3", "volume": "10", "issue": "3", "pages": "362-374" }, { "id": "authors:0nryq-vv435", "collection": "authors", "collection_id": "0nryq-vv435", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-111703486", "type": "article", "title": "A Petrologic Model for the Moon Based on Petrogenesis, Experimental Petrology, and Physical Properties", "author": [ { "family_name": "Smith", "given_name": "J. V.", "clpid": "Smith-J-V" }, { "family_name": "Anderson", "given_name": "A. T.", "clpid": "Anderson-A-T" }, { "family_name": "Newton", "given_name": "R. C.", "clpid": "Newton-R-C" }, { "family_name": "Olsen", "given_name": "E. J.", "clpid": "Olsen-E-J" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Crystallization experiments under highly reducing conditions of synthetic material of mean Apollo 11 rock composition yielded: ilmenite in at 1,150\u00b0 C; clinopyroxene in at 1,130\u00b0 C, plagioclase in at 1,120\u00b0 C. The same sequence of crystallization for the A pollo 11 vesicular ferrobasalts was interpreted from the mineral textures. The low liquidus temperature, narrow crystal-liquid interval, and delayed appearance of plagioclase are interpreted by crystallization from a magma formed by remelting of a mixture of accumulated pyroxene and ilmenite crystals in a liquid which has undergone advanced fractional crystallization. Under the Sea of Tranquillity, a residual ferrobasaltic liquid was formed by fractional crystallization of ultrabasic magma deeper in the moon. Heavy ilmenite and pyroxene crystals sank in the liquid, while light plagioclase floated to augment a crust. Meteorite impact blasted away the plagioclase-rich crust and released a ferro-basaltic magma formed by melting of ilmenite and pyroxene into the differentiated liquid. Fractional crystallization of a molten moon of modified chondritic composition yielded a small metallic core surrounded by pressure-stable, Mg-rich olivine and pyroxene. The fractionated liquid became Fe-and Ti-rich. Primitive ultrabasic crust in the highlands was augmented by dominant plagioclase-rich cumulates. The preferential occurrence of large irregular seas on the earth side of the moon is explained by differential tidal attraction of the late liquid fraction, and release by meteorite impact. The model can satisfy the density and moment of inertia of the moon if the olivine is Mg-rich. Early removal of radioactive material from the center by fractional crystallization, and enhancement of radiative heat transfer in volatile-free silicates would ease the problem of cooling the center of the moon. The low volatile content of A pollo 11 rocks may be a feature of the entire moon, permitting high rigidity and refractoriness. Incorporation of metal-seeking elements into a metal core, loss of volatiles from a hot surface, and crystal-liquid fractionation can explain some element concentrations of A pollo 11 rocks. Nevertheless the low density of the moon indicates a low Fe content of the primary material of the moon. Although there are no'meteorites which match the Apollo 11 rocks in all chemical and textural respects, several types have one or more features in common.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1970-07", "series_number": "4", "volume": "78", "issue": "4", "pages": "381-405" }, { "id": "authors:fghdb-vhg13", "collection": "authors", "collection_id": "fghdb-vhg13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-110212465", "type": "article", "title": "Petrologic History of Moon Suggested by Petrography, Mineralogy, and Crystallography", "author": [ { "family_name": "Anderson", "given_name": "A. T., Jr.", "clpid": "Anderson-A-T-Jr" }, { "family_name": "Crewe", "given_name": "A. V.", "clpid": "Crewe-A-V" }, { "family_name": "Goldsmith", "given_name": "J. R.", "clpid": "Goldsmith-J-R" }, { "family_name": "Moore", "given_name": "P. B.", "clpid": "Moore-P-B" }, { "family_name": "Newton", "given_name": "J. C.", "clpid": "Newton-J-C" }, { "family_name": "Olsen", "given_name": "E. J.", "clpid": "Olsen-E-J" }, { "family_name": "Smith", "given_name": "J. V.", "clpid": "Smith-J-V" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Opaque mineral compositions indicate that the fugacity of oxygen is approximately 10^(-13) (earth basalts, 10^(-10)). Experiments under reducing conditions suggest that the crystallization range is approximately 1140\u00b0 to 1070\u00b0C. Iron-rich pyroxmangite, fayalite, and hedenbergite occur in microgabbro. Ferropseudobrookite rimmed by ilmenite containing rutile and Cr-spinel lamellae occurs in ferrobasalt. Plagioclase vitrophyres in breccia can explain highland Surveyor VII analysis. We suggest crystal-liquid differentiation of out-gassed convecting moon with growing Fe-rich core, olivine-pyroxene mantle, plagioclase-rich dynamic crust underlain by nonspherical, inversely stratified ferrobasalt. Impact-breaking or convection-thrusting of crust releases fraction rich in Fe and Ti. Scanning electron microscopy of glass balls reveals minute depressions consistent with micrometeorite impact.", "doi": "10.1126/science.167.3918.587", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "1970-01-30", "series_number": "3918", "volume": "167", "issue": "3918", "pages": "587-590" }, { "id": "authors:ht2gh-sa022", "collection": "authors", "collection_id": "ht2gh-sa022", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-104934053", "type": "article", "title": "Experimental Studies of Igneous Rock Series: Felsic Body Suite from the Needle Point Pluton, Wallowa Batholith, Oregon", "author": [ { "family_name": "Piwinskii", "given_name": "A. J.", "clpid": "Piwinskii-A-J" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The phase relationships of four analyzed granitic rocks which comprise a late-stage felsic body sequence intruding the Mesozoic granodiorites and tonalites of the Needle Point pluton, Wallowa Batholith, Oregon, have been determined in the presence of 15 wt percent water at pressures to 3 kbar. Pressure-temperature curves were located for the beginning of melting, and for the disappearance of K-feldspar, quartz, plagio-clase, biotite, and hornblende in granodiorite no. 678, quartz monzonites nos. 685 and 774, and granite no. 705. Compositions and structural states of plagioclases from the granitic rocks, basic masses intruding the batholith, and mafic inclusions, as well as the compositions of coexisting feldspars, were determined using the electron microprobe analyzer. Variations in each of these parameters throughout the melting interval of each granitic rock were measured at 2 kbar pressure. Although experimental conditions (excess H_2O present; fO_2 regulated but not controlled) forbid detailed comparison with natural occurrences, the results indicate that, at 2 kbar pressure, temperatures of at least 730\u00b0 C and 780\u00b0 C are required to generate liquids of granite and quartz monzonite composition. Several factors suggest that the normal product of partial fusion of many crustal rock types is a H_2O-undersaturated granite liquid; crystal mushes with this type of liquid are probably involved if intermediate magmas are derived from crustal sources.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1970-01", "series_number": "1", "volume": "78", "issue": "1", "pages": "52-76" }, { "id": "authors:kk8t0-xnj95", "collection": "authors", "collection_id": "kk8t0-xnj95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-135243568", "type": "article", "title": "Melting in the deep crust and upper mantle and the nature of the low velocity layer", "author": [ { "family_name": "Lambert", "given_name": "I. B.", "clpid": "Lambert-I-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "It is possible that there are minor amounts of water in the upper mantle. This water could significantly lower melting temperatures and may give rise to melts of different composition to those formed by melting under anhydrous conditions. \n\nThis paper summarizes our experimental study of the influence of water on phase relations in natural gabbro and tonalite samples at pressures from 10 to 25 kb. Our results are used in conjunction with recently published data for other rock-water systems to discuss melting in the upper mantle and lower continental crust. It is suggested that the low velocity zone in the upper mantle could be a layer of peridotite containing interstitial melt, which may be overlain by a layer of peridotite containing interstitial \"water\". The minimum possible temperatures for the generation of andesite and basalt liquids are discussed, and it is noted that the initial melt formed from wet peridotite may be andesitic. Finally, granulite facies metamorphism in the lower continental crust and the generation of \"granites\" are considered.", "doi": "10.1016/0031-9201(70)90068-3", "issn": "0031-9201", "publisher": "Elsevier", "publication": "Physics of the Earth and Planetary Interiors", "publication_date": "1970", "volume": "3", "pages": "316-322" }, { "id": "authors:3amgw-g7r28", "collection": "authors", "collection_id": "3amgw-g7r28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160127-133607907", "type": "article", "title": "Phase relationships in the system NaAlSiO_4-SiO_2-H_2O to 35 kilobars pressure", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase relationships in the system NaAlSiO_4-SiO_2-H_2O are first presented\nin P-T projections of the composition joins NaAlSi_3O_8 (albite)-SiO_2-H_2O, NaAlSi_3O_8-H_2O,\nNaAl_2Si_2O_6 (jadeite)-H_2O, and NaAlSi_2O_6-NaAlSiO_4 (nepheline)-H_2O. Crystalline\nphases encountered include albite, analcite, coesite, jadeite, nepheline, and quartz.\nVapor-saturated melting curves for these compositions, including those for the melting\nof albite + quartz + vapor, albite + vapor, and albite + analcite + vapor, proceed\nwith negative dP/dT slopes to invariant points at pressures between 10 and 13 kb\nwhere jadeite coexists with liquid.\nAt higher pressures, the solidus curves for compositions on these joins extend with\npositive dP/dT slopes, and the quartz-bearing assemblages terminate at an invariant\npoint marking the appearance of coesite. Albite-H_2O compositions melt incongruently\nat pressures greater than a singular point at 16 kb, and jadeite-H_2O compositions\nmelt congruently above a singular point at 13 kb and form a stable thermal divide\nwithin this system.\nTogether with the chemographic methods of Schreinemakers and experimental\ndata for the system NaAlSiO_4-SiO_2, univariant and invariant equilibria for the ternary\nsystem are presented in P-T projection. The approximate solubility of H_2O in\nliquids of albite, nepheline, and jadeite composition at 15 kb is 27 (wt) percent, 36\npercent and 22 percent, respectively. Nepheline-H_2O compositions are not binary at\nthese pressures and break down to a jadeite-bearing assemblage at pressures above\n10 kb and to jadeite + an unknown phase at higher pressures.\nIsobaric-polythermal diagrams, constructed on the basis of the melting relationships\nand solubility data, illustrate the primary fields for the crystalline phases and\ndisclose that critical phenomena will intervene only for compositions rich in SiO_2.", "doi": "10.2475/ajs.267.8.875", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1969-10", "series_number": "8", "volume": "267", "issue": "8", "pages": "875-909" }, { "id": "authors:3cfh0-5hh83", "collection": "authors", "collection_id": "3cfh0-5hh83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160209-093518164", "type": "article", "title": "Melting Relationships in the System NaAlSi_3O_8-NaCl-H_2O at One Kilobar Pressure, with Petrological Applications", "author": [ { "family_name": "van Groos", "given_name": "A. F. Koster", "clpid": "van-Groos-A-F-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase relationships in the system NaAlSi_3O_8-NaCl-H_2O appear to be ternary between 850\u00b0 C and 950\u00b0 C at 1 kbar pressure. A two-phase field containing NaCl-rich liquid and H_2O-rich vapor extends from the system NaCl-H_2O into the ternary system, although this field was not intersected by the joins investigated. In the system NaAlSi_3O_8-H_2O a wide miscibility gap occurs between liquid and vapor; in the system NaAlS_2O_8-NaCl a wide miscibility gap extends between silicate-rich liquid and NaCl-rich liquid at temperatures above 1,100\u00b0 C at 1 bar pressure and also by inference at 1 kbar pressure. Both miscibility gaps are connected through the ternary system, separating a silicate liquid from a fluid phase with composition close to the join NaCl-H_2O and containing a small, unknown proportion of dissolved silicates. A temperature minimum is present on the ternary liquidus at 873 \u00b1 5\u00b0 C, representing the reaction: Albite+Fluid (H_2O-Nacl) \u21d4 Liquid_(Albite) (1)\nThe liquid composition, in terms of the anhydrous components, is approximately 99.7 wt percent NaAlSi_3O_8, 0.3 wt percent NaCl; its H_2O content is about 10 wt percent. It is expected that at lower pressures two additional reactions will occur: Albite+Vapor=Liquid_(Albite)+Liquid_(Nacl) (2) and Albite+Liquid_(Nacl)+Vapor; \u21d4 Liquid_(Albite). (3)\nThe results contrast with those in the system NaAlSi_3O_8-NaF-H_2O and confirm previous conclusions from the systems NaAlSi_3O_8-HCL-H_2O and NaAlSi_3O_8-HF-H_2O. Whereas fluoride (or NaF) tends to remain in the liquid (magma), chlorine (or NaCl) passes preferentially into the vapor or fluid phase. The solubility of H2O in a silicate melt increases when a small quantity of chlorine is present. Coexistence of H_2O-rich liquid inclusions and NaCl-rich liquid inclusions in crystalline phases in igneous rocks may indicate low-pressure conditions (<1 kbar) during capture of the inclusions.", "doi": "10.1086/627455", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1969-09", "series_number": "5", "volume": "77", "issue": "5", "pages": "581-605" }, { "id": "authors:s0rvz-qvt30", "collection": "authors", "collection_id": "s0rvz-qvt30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-133143645", "type": "article", "title": "Phase Equilibrium Studies Bearing on the Limestone-Assimilation Hypothesis", "author": [ { "family_name": "Watkinson", "given_name": "David H.", "clpid": "Watkinson-D-H" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase relationships in parts of the join NaAlSi_3O_8-CaCO_3-Ca(OH)_2-H_2O at 1-kb pressure, 600\u00b0 C to 1100\u00b0 C, illustrate the effect of limestone assimilation on feldspathic magmas. Addition of 20 weight percent of CaO-rich material to a vapor-saturated albite liquid introduces the successive phase fields plagioclase + L + V, wollastonite + L + V, and plagioclase + wollastonite + L + V: addition of 20 to 25 percent produces a small field just above the solidus for plagioclase + wollastonite + nepheline + L + V, with nepheline present in trace amounts; crystallization of the liquid yields little additional nepheline: 25 percent or more of CaO-rich material causes complete crystallization because the solidus temperature increases abruptly, then more nepheline develops and melilite, rankinite, and larnite are stabilized in a series of subsolidus phase fields. Thus, about 20 weight percent of limestone must be assimilated before a feldspathic melt becomes sufficiently desilicated to yield nepheline. Even if enough superheat is available to permit solution of so much limestone, assimilation causes crystallization before desilication proceeds very far, and the formation of feldspathoids in quantity results only from subsolidus reactions. Limestone assimilation releases CO_2, which also tends to induce crystallization of a hydrated magma. A magma would be forced to crystallize as syntexis proceeds, and the local formation of alkalic silica-undersaturated rocks in reaction zones at limestone contacts with silica-saturated igneous magmas is to be expected. The development of large volumes of alkalic, silica-undersaturated magma by limestone syntexis appears to be unlikely, however. Production of alkalic magma by sialic-rock assimilation by carbonatite magma is similarly unlikely.", "doi": "10.1130/0016-7606(1969)80[1565:PESBOT]2.0.CO;2", "issn": "0016-7606", "publisher": "Geological Society of America", "publication": "Geological Society of America Bulletin", "publication_date": "1969-08", "series_number": "8", "volume": "80", "issue": "8", "pages": "1565-1576" }, { "id": "authors:3x3cn-43s64", "collection": "authors", "collection_id": "3x3cn-43s64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160111-155943308", "type": "article", "title": "The origin of ultramafic and ultrabasic rocks", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Ultramafic rocks are classified in terms of their field associations and tectonic environment. Eleven associations are distinguished, some with subdivisions. The major features of each association are described in turn, and it is emphasized that the variety of field and petrographic associations indicates that a variety of processes is involved in the origin and emplacement of these rocks. For petrogenetic discussion the-associations are considered in three groups: (1) layered, stratiform and other intrusions involving gabbro or diabase together with accumulations or concentrations of mafic minerals; (2) the alkalic rocks of stable continental regions; including kimberlites, mica peridotite, members of ring complexes, and ultrabasic lava flows; (3) the several peridotite-serpentinite associations of the orogenic belts that have been classified together as alpine-type intrusions. The petrogenesis of ultramafic nodules in alkali basalts and kimberlites is also discussed. The petrogenesis of these rocks is concerned with the source of the material, its variation in physical state and temperature from source to position of intrusion, and its post-intrusion history. The study of ultramafic rocks and nodules is one approach towards determination of the composition and mineralogy of the upper mantle.", "doi": "10.1016/0040-1951(69)90015-8", "issn": "0040-1951", "publisher": "Elsevier", "publication": "Tectonophysics", "publication_date": "1969-06", "series_number": "5-6", "volume": "7", "issue": "5-6", "pages": "437-455" }, { "id": "authors:5kyvc-6qa73", "collection": "authors", "collection_id": "5kyvc-6qa73", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160121-140123957", "type": "article", "title": "Melting reactions in the system KAlSi_3O_8-SiO_2-H_2O to 18.5 kilobars", "author": [ { "family_name": "Lambert", "given_name": "I. B.", "clpid": "Lambert-I-B" }, { "family_name": "Robertson", "given_name": "J. K.", "clpid": "Robertson-J-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Synthetic sanidine with composition Or_(95)Ab_5 was crystallized from gel,\nand a portion was mixed with 15 wt percent natural quartz. The sanidine and\nsanidine-quartz mixture were reacted with 30 to 40 wt percent water in sealed platinum\ncapsules, using piston-cylinder apparatus. The melting relationships for these\ntwo crystalline mixtures, in the presence of excess water, were determined to 18.5 kb\npressure. The divariant melting intervals located for each sample, along with the results\nof previous studies in the system KAlSi_3O_8-SiO_2-H2_O, provided good estimates\nof the positions of univariant curves for the two reactions: (a) Or + V <--> L, and (b) Or + Qz + V <--> L. Values for reaction (a) are 5 kb-875\u00b0C; 10 kb-825\u00b0C; 15 kb-795\u00b0C;\n20-775\u00b0C. Values for reaction (b) are 5 kb-740\u00b0C; 10 kb-710\u00b0C; 15 kb-700\u00b0C; 20 kb-\n697\u00b0C. Muscovite was present in trace amounts in all runs, including those quenched\nfrom conditions well above its maximum temperature stability limit, but it was not\nfound enclosed in glass. We therefore conclude that muscovite was a deposit from the\nvapor phase. Schematic phase diagrams for the system K_2O-Al_2O_3-SiO_2-H_2O indicate\nthat muscovite would not be expected as a stable liquidus phase for mixtures on the\njoin KAlSi_3O_8-SiO_2-H_2O at pressures less than 10 kb.", "doi": "10.2475/ajs.267.5.609", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1969-05", "series_number": "5", "volume": "267", "issue": "5", "pages": "609-626" }, { "id": "authors:qh4cz-3vs25", "collection": "authors", "collection_id": "qh4cz-3vs25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-132656207", "type": "article", "title": "The system CaO-SiO_2-CO_2-H_2O\u2014III. Second critical end-point on the melting curve", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Melting relationships in the system CaO-SiO_2-CO_2-H_2O have been extended to 40 kbar pressure. Dellaite, dicalcium silicate, spurrite and ealciochondrodite appear as the silicate phases coexisting with vapor-saturated liquids and fluids at high pressures. Contrary to earlier predictions, wollastonite does not appear on the vapor-saturated liquidus, at least to pressures below 10 kbar. The solidus terminates at a second critical end-point at about 32.5 kbar and 515\u00b0C. To provide a model for our results in this quaternary system, phase relationships in a hypothetical ternary system with critical end-points are developed. An extension of these relationships into the system CaO-SiO_2-CO_2-H_2O shows that a critical curve limiting the miscibility gap between liquids and vapors moves through the system with changing pressure, terminating a series of univariant reactions at critical end-points. The results are applicable to the origin of carbonatites and associated alkalic rocks and kimberlites and they illustrate that fractional crystallization in this system will produce carbonatitic melts only from liquids originally undersaturated in silica, at least for a pressure range prevailing within the earth's crust.", "doi": "10.1016/0016-7037(69)90018-0", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1969-05", "series_number": "5", "volume": "33", "issue": "5", "pages": "611-632" }, { "id": "authors:55nhk-k1q87", "collection": "authors", "collection_id": "55nhk-k1q87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-100248137", "type": "article", "title": "Experimental Studies of Igneous Rock Series: The Farrington Complex, North Carolina, and the Star Mountain Rhyolite, Texas", "author": [ { "family_name": "Gibbon", "given_name": "D. L.", "clpid": "Gibbon-D-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The phase relationships of four specimens from the Farrington Complex ranging in composition from granite to tonalite, and of four specimens from the Star Mountain Rhyolite, have been determined in the presence of 15-20 weight per cent H_2O in the pressure range from 1 to 3 kb. PT curves have been located for the beginning of melting and for the complete melting of quartz, alkali feldspar, and plagioclase. Glass percentages have been determined for representative samples by point counting in polished thin sections. The melting relationships for these two widely different series of rocks aid in defining the primary phase volumes in the \"Granodiorite Tetrahedron.\" It has not been possible experimentally to reproduce the unusual natural phenocryst-groundmass relationships of the Star Mountain Rhyolite; this failure is attributed at least partly to the experimental condition of excess water, and confirms the conclusion, drawn from petrographic evidence, that these magmas were erupted with very low water contents.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1969-03", "series_number": "2", "volume": "77", "issue": "2", "pages": "221-239" }, { "id": "authors:eza11-9gy32", "collection": "authors", "collection_id": "eza11-9gy32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-155840656", "type": "article", "title": "Liquidus Phase Relationships in the System CaO-CO_2-H_2O to 40 Kilobars Pressure with Petrological Applications", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" } ], "abstract": "Two melting reactions, (i) CaCO_3 + Ca(OH)_2 = liquid and (ii) CaCO_3 + Ca(OH)_2 + vapor = liquid, have been extended from 4 kb to 40 kb using piston-cylinder\napparatus. Points measured for reaction (i) are: 655\u00b0C at 4 kb, 659\u00b0C at 15.5\nkb, 662\u00b0C at 25 kb, and 666\u00b0C at 40.7 kb; and for reaction (ii): 630\u00b0C at 4 kb, 565\u00b0C\nat 15.5 kb, 537\u00b0C at 25 kb, and 524\u00b0C at 40.8 kb. A pressure-temperature projection\nfor the system CaO-CO_2-H_2O is presented, in part schematic, from 300\u00b0C to 1500\u00b0C\nand from l bar to 40 kb. The carbonate phase changes from calcite to aragonite with\nincreasing pressure. The compositions of the liquid and vapor phases appear to remain\nquite distinct up to 40 kb, hut conditions above a hypothetical second critical endpoint\nfor reaction (ii) are illustrated. Textures observed in the quenched liquids are\ncompared with textures described in carbonatites and adduced as evidence supporting\na magmatic origin for these carbonatites.", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1969", "volume": "267-A", "pages": "489-508" }, { "id": "authors:wzq64-04d07", "collection": "authors", "collection_id": "wzq64-04d07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160114-110646091", "type": "article", "title": "Experimental studies in \"granitic\" systems with volatile components", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "[no abstract]", "issn": "0019-5928", "publisher": "Mineralogical Society of India", "publication": "Indian Mineralogist", "publication_date": "1969", "volume": "10", "pages": "116-139" }, { "id": "authors:6kme1-f9w03", "collection": "authors", "collection_id": "6kme1-f9w03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160203-100144081", "type": "article", "title": "Liquid immiscibility in the join NaAlSi_3O_8-Na_2CO_3-H_2O and its bearing on the genesis of carbonatites", "author": [ { "family_name": "van Groos", "given_name": "A. F. Koster", "clpid": "van-Groos-A-F-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase relationships in the join NaAlSi_3O_8-Na_2CO_3-H_2O through the\nquinany system Na_2O-Al_2O_3-SiO_2-CO_2-H_2O were studied experimentally at 1 kb as\npart of a series of studies aimed at elucidating the relationships between alkaline\nigneous rocks and their associated carbonatites. The phases encountered are albite,\ncancrinite, sodium carbonate, a silicate-rich liquid, an Na_2CO_3-rich liquid, and vapor.\nA liquid miscibility gap between the two liquid phases is intersected by this join\nover a wide range of compositions at temperatures in excess of 725\u00b0C; the compositions\nof the liquids approach each other with increasing H_2O content at constant temperature.\nThe minimum temperature of the vapor-saturated liquidus decreases continuously\nwith increasing H_2O content; it lies at 865\u00b0C for a composition of 81 wt percent\nNaAlSi_3O_8, 19 wt percent Na_2CO_3 with no H_2O present, and at 645\u00b0C for an anhydrous\ncomposition of 80 wt percent NaAlSi_3O_8, 20 wt percent Na_2CO_3 with 50 wt\npercent H_2O present. The minimum temperature on the solidus decreases from\n685\u00b0C with 5 wt percent H_2O present to 590\u00b0C with 75 percent H_20 present for an\nanhydrous composition 75 wt percent NaAlSi_3O_8 + 25 wt percent Na_2CO_3. Albite is\nthe main silicate phase al low H_2O contents, while cancrinite is the main silicate\nphase at high H_2O contents. The three fluid phases which coexist in this simplified\nsystem are: (1) an undersaturated alkaline silicate liquid, (2) an alkaline carbonate\nliquid containing only a small amount of dissolved silicate, and (3) a vapor phase\nwith a composition varying between H_2O and CO_2, and containing Na_2O and SiO_2\nin solution. These fluid phases can be compared with, respectively, (1) nepheline or\nijolite magmas, (2) carbonatite melts, and (3) fenitizing solutions, which together form\ncomplexes of alkaline igneous rocks and associated carbonatites. It is proposed that\nprocesses of fractional crystallization in a carbonated alkalic magma, combined with\nvapor transport, can result in the formation of these three coexisting fluid phases.", "doi": "10.2475/ajs.266.10.932", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1968-12", "series_number": "10", "volume": "266", "issue": "10", "pages": "932-967" }, { "id": "authors:p12e6-6jh95", "collection": "authors", "collection_id": "p12e6-6jh95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-093649285", "type": "article", "title": "Opaque oxide minerals of some diabase-granophyre associations in Pennsylvania", "author": [ { "family_name": "Davidson", "given_name": "A.", "clpid": "Davidson-A" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Optical examination of the opaque oxide minerals in specimens of diabase, intermediate\ngranophyric diabase, granophyre, and diabase pegmatite from Triassic intrusions\nof Pennsylvania revealed distinct changes through the diabase-granophyre differentiation\nsequence. Qualitative electron microprobe scans across complex mineral grains supplemented\nand confirmed the optical interpretations. The opaque oxide minerals consist\nalmost entirely of ilmenite, magnetite, and ulvospinel, and they comprise between 1 and\n10 percent of the rocks in the diabase-granophyre sequence. Magnetite occurs in two\nforms: the first contains exsolved ulvospinel and is intimately associated with ilmenite;\nthe second is Ti-poor and it does not contain microscopically visible Ti-bearing phases.\nThe second form occurs as rims on the first or as separate crystals in differentiated\nrocks. Ilmenite occurs as intergrowths, as skeletal growths, and as individual crystals.\nAccompanying the igneous differentiation sequence there is a gradation from titaniferous\nmagnetite with ilmenite, to skeletal ilmenite retaining an original spinel outline. We\nsuggest that during the stage of iron-enrichment in the igneous differentiation sequence\nan aqueous fluid developed within the crystallizing intermediate magma and was capable\nof dissolving iron from the titaniferous magnetite intergrowths, leaving skeletal crystals\nof ilmenite. Some or all of this iron was redeposited as a second generation of Ti-poor\nmagnetite within the source rock. It is possible that iron-bearing solutions so derived\ncould escape to higher levels where they would be a potential source of magnetite\ndeposits of Cornwall type.", "doi": "10.2113/gsecongeo.63.8.950", "issn": "0361-0128", "publisher": "Society of Economic Geologists", "publication": "Economic Geology", "publication_date": "1968-12", "series_number": "8", "volume": "63", "issue": "8", "pages": "950-960" }, { "id": "authors:01cj5-ygc84", "collection": "authors", "collection_id": "01cj5-ygc84", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-130655484", "type": "article", "title": "Stability of Hornblende and a Model for the Low Velocity Zone", "author": [ { "family_name": "Lambert", "given_name": "I. B.", "clpid": "Lambert-I-B" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "There have been many discussions, but few experiments, related to the occurrence and stability of hornblende in the upper mantle. We have obtained evidence relating to hornblende stability in experiments which extend the phase relationships for calc\u2013alkaline rock series (gabbro\u2013tonalite\u2013granite) to upper mantle pressures, in the presence of excess water, and these experiments have a bearing on the proposals that some intermediate rocks are derived by melting in the upper mantle. They complement other experiments dealing with dry rocks, or with rocks in the presence of water with P_(H_2O) < P_(load) (ref. 4).", "doi": "10.1038/2191240a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1968-09-21", "series_number": "5160", "volume": "219", "issue": "5160", "pages": "1240-1241" }, { "id": "authors:whdg1-fb838", "collection": "authors", "collection_id": "whdg1-fb838", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-091148120", "type": "article", "title": "Jadeite stability measured in the presence of silicate liquids in the system NaAlSiO_4-SiO_2-H_2O", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The reactions nepheline + high albite \u21cb Jadeite and high albite \u21cc Jadeite + quartz were measured in the presence of high-pressure vapors and silicate melts in the system NaAlSiO_4-SiO_2-H_2O for the temperature range 600\u2013800\u00b0C. Kinetics were such that complete reaction was attained in most runs. The results of these determinations together with previous studies in this system and recent thermochemical data collectively place narrow restrictions on the positions of the above reactions over a wide temperature range. An entropy change of 3.5 eu accompanying the transformation of low to high albite is in good agreement with these results. Some data are also provided for the reaction analcite + high albite \u21cb Jadeite + vapor. It is concluded that Jadeite can form in a variety of geologic environments at pressures lower than previously determined.", "doi": "10.1016/0016-7037(68)90064-1", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1968-09", "series_number": "9", "volume": "32", "issue": "9", "pages": "999-1012" }, { "id": "authors:jyhrb-fbg78", "collection": "authors", "collection_id": "jyhrb-fbg78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-105328706", "type": "article", "title": "The Calcite-Aragonite Transition Measured in the System CaO-CO_2-H_2O", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The study of melting reactions in the system CaO-CO_2-H_2O included redetermination of the calcite-aragonite\ntransition boundary. The morphology of aragonite in equilibrium with the ternary liquid is distinct\nfrom that of calcite; the original shape of calcite or aragonite becomes frozen into the liquid during the\nquench and is preserved for microscopic examination regardless of the polymorphic changes that occur in\nquenching. The shape of the carbonate crystals in the quenched assemblage CaCO_3 + liquid + vapor was\ntherefore used to bracket the calcite-aragonite transition boundary. Some original aragonite crystals inverted\nto biaxial calcite during the quench. The kinetics of the inversion are strongly influenced by crystal\nsize. The transition boundary was extended below the solidus temperature (580\u00b0 C. at 12.1 kb.) on the basis\nof microscopic examination of morphology of the quenched crystals, supplemented by X-ray diffraction\npatterns. The reaction was reversed at several points. The transition boundary changes slope at 480\u00b0 C. and\n9.4 kb., the triple point for aragonite + calcite I + calcite II. This change in slope is probably caused by\n\u0394S for calcite I - calcite II, because \u0394V is insignificant. The lowest point measured on the aragonite-calcite I\ncurve is 400\u00b0 C. at 8.3 kb., and the highest point measured on the aragonite-calcite II curve is 800\u00b0 C.\nat 19.8 kb. These results are compared with a detailed review of previous experimental determinations. Geological\napplications of the calcite-aragonite geobarometer are discussed, as well as the possible use of biaxial\ncalcite as a criterion for recognizing inverted aragonite.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1968-05", "series_number": "3", "volume": "76", "issue": "3", "pages": "314-330" }, { "id": "authors:2h702-wcs46", "collection": "authors", "collection_id": "2h702-wcs46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-101813867", "type": "article", "title": "Experimental Studies of Igneous Rock Series: A Zoned Pluton in the Wallowa Batholith, Oregon", "author": [ { "family_name": "Piwinskii", "given_name": "A. J.", "clpid": "Piwinskii-A-J" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The phase relationships of five analyzed granodiorites and tonalites from the zoned Needle Point Pluton\nof the Wallowa Batholith, Oregon, supplied by W. H. Taubeneck, have been determined in the presence of\n15-25 weight per cent H_2O at pressures to 3 kb. Pressure-temperature curves were located for the beginning\nof melting and for the disappearance of K-feldspar, quartz, plagioclase, biotite, and hornblende. For two\nspecimens, a granodiorite and a tonalite, the melting behavior at 2 kb. pressure was determined in more\ndetail with approximate point counts of crushed fragments. Representative results are: granodiorite (Differentiation\nIndex [D.I.] 76) melting begins at 705\u00b0 C., K-feldspar disappears at 710\u00b0 C., quartz disappears\nat 735\u00b0 C.; tonalite (D.I. 55) melting begins at 725\u00b0 C., the trace of K-feldspar disappears at the same temperature,\nquartz disappears at 755\u00b0 C. In both rocks, calcic plagioclase, amphibole, and opaque minerals\nremain at 900\u00b0 C. The hornblende becomes unstable at a slightly higher temperature and passes into the\nmelt phase. Forty-seven per cent of the granodiorite melts between 705\u00b0 and 730\u00b0 C., and 55 per cent melts\nat 900\u00b0 C. Twenty-nine per cent of the tonalite melts between 730\u00b0 and 800\u00b0 C., and 32 per cent melts at\n900\u00b0 C. At 900\u00b0 C., the approximate plagioclase content of the granodiorite is 27 per cent, and of the tonalite\n40 per cent; the glass in each rock has a refractive index of 1.510 \u00b1 0.002. The experimental conditions\n(excess H_2O; f_(O_2) not controlled) prohibit detailed comparison with the natural occurrences. However, the\npersistence of calcic plagioclase and hornblende in abundance at 900\u00b0 C. at 2 kb. pressure indicates that if\nthese rocks were formed by anatexis, then either high temperatures are required at the base of the crust or\nthe magmas consisted of a eutectic-type granite liquid with suspended crystals. The high liquidus temperatures\nsuggest that gabbroic magma may be involved in the development of magmas of intermediate composition\nin batholiths.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1968-03", "series_number": "2", "volume": "76", "issue": "2", "pages": "205-234" }, { "id": "authors:3kq2p-5d943", "collection": "authors", "collection_id": "3kq2p-5d943", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160129-091937540", "type": "article", "title": "The quartz-coesite transition measured in the presence of a silicate liquid and calibration of piston-cylinder apparatus", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Hydrothermal melting reactions in the system NaAlSiO_4-SiO_2-H_2O have been extended into the coesite stability field using piston-cylinder apparatus, and the quartz-coesite transition has been bracketed at 735\u00b0 (28.0\u00b10.9 Kb) and at 800\u00b0 C (28.15\u00b10.9 Kb) in the presence of a silicate liquid phase; this provided favorable kinetic conditions. The results agree closely with previous piston-cylinder determinations employing a correction for pressure loss due to friction. Consideration of previous calibration and hysteresis experiments leads to the conclusion that despite its potential utility, the quartz-coesite transition can not be confidently used as a calibrant for piston-cylinder apparatus until the question of whether or not to apply a friction correction has been resolved.", "doi": "10.1007/BF00388945", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "1968-03", "series_number": "3", "volume": "17", "issue": "3", "pages": "224-232" }, { "id": "authors:z12za-fqg16", "collection": "authors", "collection_id": "z12za-fqg16", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-103330817", "type": "article", "title": "Melting of Granite with Excess Water to 30 Kilobars Pressure", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "A chemically analyzed biotite granite from the Dinkey Lakes, Sierra Nevada Batholith, consists of 34.8\nper cent quartz, 31.5 per cent plagioclase, 29 per cent orthoclase, and 4.7 per cent mafic minerals (mainly\nbiotite). The crushed rock, sealed with 25-35 wt. per cent H_2O in platinum capsules, was reacted in piston-cylinder\napparatus. The curve for the beginning of melting passed through 620\u00b0 \u00b1 5\u00b0 C. at 10 kb. and\n605\u00b0 \u00b1 5\u00b0 C. at 15.3 kb. At about 17 kb., the plagioclase broke down to yield jadeite and quartz, and the\nsolidus curve then began to increase in temperature with increasing pressure, reaching 670\u00b0 C. at 27 kb. At\nhigher pressures, quartz was transformed to coesite, and the melting curve continued to rise. In subsolidus\nruns at 20 kb., the original orthoclase and biotite were completely dissolved in the aqueous vapor phase.\nThese experimental results, along with similar results in the SiO_2-excess portion of the system NaAlSiO_4-\nSiO_2-H_2O, provide no support for the theoretical predictions that solid-liquid-vapor melting curves should\npass through a temperature minimum at 10 kb. or less. The water-saturated melting curve for the granite\nprovides physical limits for the generation of silicate magmas within the crust and mantle.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1968-03", "series_number": "2", "volume": "76", "issue": "2", "pages": "235-244" }, { "id": "authors:vzn27-x4x09", "collection": "authors", "collection_id": "vzn27-x4x09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-091759554", "type": "article", "title": "Melting Relationships in the System NaAlSi_3O_8-NaF-H_2O to 4 Kilobars Pressure", "author": [ { "family_name": "van Groos", "given_name": "A. F. Koster", "clpid": "van-Groos-A-F-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The phase relationships in the systems NaF-H_2O and NaAlSi_3O_8-NaF-H_2O were determined between\n600\u00b0 and 900\u00b0 C. at pressures up to 4 kb., and those in the anhydrous system NaAlSi_3O_8-NaF were determined\nat 1 atm. The phases encountered were albite, villiaumite (NaF), liquid, and vapor. The liquid quenches\nto a glass containing skeletal NaF crystals. Primary villiaumite is readily distinguished from \"quench\"\nNaF. Albite crystals coexisting with liquid are several times larger than subsolidus crystals. The binary reaction\nvilliaumite + vapor \u2194 liquid occurs at 860\u00b0 \u00b1 7\u00b0 C. at 1 kb., and the binary reaction albite +\nvilliaumite \u2194 liquid occurs at 860\u00b0 \u00b1 5\u00b0 C. at 1 atm. The beginning of melting in the ternary system is the\nreaction albite + villiaumite + vapor \u2194 liquid; this occurs at 753\u00b0 \u00b1 5\u00b0 C. at 0.5 kb., at 688\u00b0 \u00b1 5\u00b0 C. at\n1 kb., at 640\u00b0 \u00b1 5\u00b0 C. at 2 kb., at 630\u00b0 \u00b1 5\u00b0 C. at 3 kb., and at 600\u00b0 \u00b1 5\u00b0 C. at 4 kb. The composition of\nthe univariant liquid in the system NaF-H_2O at 1 kb. is approximately 80 wt. per cent NaF and 20 wt. per\ncent H_2O; the composition of the univariant liquid in the anhydrous system is approximately 84 wt. per cent\nNaAlSi_3O_8 and 16 wt. per cent NaF. The composition of the univariant liquid in the ternary system varies\nwith pressure. At 1 kb. the composition expressed in terms of the anhydrous components is approximately\n86 wt. per cent NaAlSi_3O_8 and 14 wt. per cent NaF, and the water content is about 30 wt. per cent; at 4\nkb. it is approximately 75 wt. per cent NaAlSi_3O_8 and 25 wt. per cent NaF, and with a water content of\nabout 45 wt. per cent. Critical conditions are probably reached at a pressure not far above 4 kb. The solubility\nof the solids in the vapor phase at 4 kb. is about 40 wt. per cent. These results indicate that small variations\nin NaF content of a silicate magma can produce large variations in the water content of residual magmas and\nlarge variations in the amount of water required to saturate the magma. NaF causes residual magmas to\npersist to significantly lower temperatures than the final consolidation temperature if H_2O were the only\ndissolved volatile component.", "issn": "0022-1376", "publisher": "University of Chicago Press", "publication": "Journal of Geology", "publication_date": "1968-01", "series_number": "1", "volume": "76", "issue": "1", "pages": "50-70" }, { "id": "authors:yzwm7-c7q79", "collection": "authors", "collection_id": "yzwm7-c7q79", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-105310435", "type": "article", "title": "Hydrothermal Melting Curves in Silicate\u2013Water Systems at Pressures greater than 10 Kilobars", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Fusion curves, or melting intervals, for many elements, minerals and rocks have now been measured experimentally to high pressures, but most determinations of melting relationships in the presence of water vapour have been limited to pressures below 10 kbar. It is well known that the solubility of water vapour under pressure in silicate liquids produces a marked depression of melting temperatures, as illustrated by the negative slopes, dP/dT, of the univariarit curves for the reactions: albite + vapour = liquid (Fig. 1); albite + nepheline + vapour = liquid (Fig. 2). Barth, Smith and Kadik and Khitarov have predicted that, because of the progressive change in the relative properties of water in vapour and liquid phases with increasing pressure, the slopes, dP/dT, of hydrothermal melting curves in silicate\u2013water systems (solid\u2013liquid\u2013vapour) should change from negative to positive at moderate pressures, probably within the interval 3 kbar\u201310 kbar, with the curves passing through a temperature minimum where dT/dP = 0. We have recently extended water saturated univariant melting curves in the system NaAlSiO_4\u2013SiO_2\u2013H_2O from 10 to 35 kbar, using piston\u2013cylinder apparatus, and none of the curves exhibited a temperature minimum where dT/dP = 0. Figs. 1 and 2 show some of our results. These are not complete phase diagrams; they show only the reactions encountered by two composition joins through the ternary system. Further reactions required by the existence of invariant points, I, and a singular point, S_5, will be illustrated elsewhere.", "doi": "10.1038/216572a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1967-11-11", "series_number": "5115", "volume": "216", "issue": "5115", "pages": "572-573" }, { "id": "authors:zkcpb-vyz20", "collection": "authors", "collection_id": "zkcpb-vyz20", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-151559197", "type": "article", "title": "Biaxial calcite inverted from aragonite", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "We have recently extended the phase relationships involving a liquid\nphase in the system CaO-CO_2-H_2O from 4 kilobars pressure (Wyllie and\nTuttle, 1960; Wyllie and Raynor, 1965) to 40 kilobars pressure (to be\npublished). Under appropriate conditions the phase assemblage calcite+liquid+vapor undergoes a transition to aragonite+liquid+vapor.\nPublished data indicate that the calcite-aragonite transition curve should\nintersect the ternary univariant solidus curve at about 580\u00b0C at a pressure\nbetween 11.5 and 13 kilobars. At temperatures above 600\u00b0C, BeIl\nand England (1964) concluded that the aragonite which formed stably\nwithin a wide pressure interval inverted to calcite during the quench.\nThus, quenching problems have apparently contributed to the conflicting\nreports for the position of the calcite-aragonite phase transition. Examination\nof the morphology of the carbonate in the quenched assemblage CaCO_3+liquid+vapor suggested a method for locating the calcite-aragonite\ntransition boundary regardless of the polymorphic changes\nthat may occur during the quench.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1967-09", "series_number": "9-10", "volume": "52", "issue": "9-10", "pages": "1527-1529" }, { "id": "authors:myk9t-b0r06", "collection": "authors", "collection_id": "myk9t-b0r06", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-095848553", "type": "article", "title": "Serpentine Dehydration Curves and their Bearing on Serpentinite Deformation in Orogenesis", "author": [ { "family_name": "Scarfe", "given_name": "C. M.", "clpid": "Scarfe-C-M" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Serpentinite bodies characteristically occur in regions that have undergone an orogenesis of alpine type. The more recent recognition that significant quantities of serpentinites are associated with the oceanic crust, oceanic trenches and mid-oceanic ridges extends the possible role of serpentinites in tectonic processes which involve the crust and upper mantle. Thus the experimental deformation of serpentinite at high pressures and temperatures has important implications for theories of the tectonic emplacement of serpentinites and principal tectonic processes such as mountain building. Raleigh and Paterson have found that at low temperatures and high pressures serpentine has strength comparable with granite. With an increase in temperature sealed specimens showed marked weakening accompanied by the development of brittleness.", "doi": "10.1038/215945a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1967-08-26", "series_number": "5104", "volume": "215", "issue": "5104", "pages": "945-946" }, { "id": "authors:dce43-r3h39", "collection": "authors", "collection_id": "dce43-r3h39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-124541278", "type": "article", "title": "Revision of the Calcite\u2013Aragonite Transition, with the Location of a Triple Point between Calcite I, Calcite II and Aragonite", "author": [ { "family_name": "Boettcher", "given_name": "A. L.", "clpid": "Boettcher-A-L" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Conflicting reports have been published for the position of the calcite\u2013aragonite phase transition, and two factors contributing to this are the slow solid state reaction kinetics and the problems of quenching the stable assemblage. Bell and England concluded from their experiments that aragonite which formed stably within a wide pressure range (above 600\u00b0 C) inverted to calcite during the quench. We have recently extended the phase relationships involving a liquid phase in the system calcium oxide\u2013carbon dioxide\u2013water from 4 kbars pressure to 40 kbars using a piston-and-cylinder high-pressure apparatus. The liquids in this system are very reactive media, and no problems have been encountered in reaching equilibrium in this and a variety of related systems. Across the calcite\u2013aragonite boundary, the ternary phase assemblage calcite + liquid + vapour undergoes a transition to aragonite + liquid + vapour. In runs completed at pressures well above and well below the phase boundary, aragonite and calcite crystals in the quenched assemblage calcium carbonate + liquid + vapour were positively identified by X-ray and optical properties. The morphology of aragonite crystals coexisting with the ternary liquid is distinct from that of the calcite crystals, and the original shape of the equilibrium phase, aragonite or calcite, becomes frozen into the surrounding liquid during the quench and is thus preserved for microscopic examination. The shape of the carbonate crystals in the quenched assemblage calcium carbonate + liquid + vapour was therefore used to bracket the calcite\u2013aragonite transition boundary down to the solidus temperature at 580\u00b0 C. X-ray powder diffraction and refractive-index measurements demonstrate that crystals with the morphology of aragonite, in runs close to the transition boundary, have inverted to complexly twinned, biaxial calcite with optic axial angles ranging from near zero up to an estimated 20\u00b0 (2V for aragonite is 18\u00b0). The implications of this observation have been discussed elsewhere.", "doi": "10.1038/213792a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1967-02-25", "series_number": "5078", "volume": "213", "issue": "5078", "pages": "792-793" }, { "id": "authors:770xv-k8606", "collection": "authors", "collection_id": "770xv-k8606", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130821-141638115", "type": "article", "title": "Phase Equilibria in System CaO-CO_2-H_2O and Related Systems, with Implications for Crystal Growth of Calcite and Apatite", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Conditions for crystallization of calcite from melts in the presence of a vapor or gaseous phase are reviewed to provide possible guidelines for growth of calcite. Phase equilibrium data for the system CaO-CO_2 show that to precipitate calcite from molten CaCO_3 the temperature must be above 1230\u00b0 C and excess CO2 must be present at pressures greater than 39.5 bars. Phase equilibrium data for the system CaO-CO_2-H_2O show that calcite can be precipitated from melts at 650\u00b0C in the presence of an aqueous vapor phase at 10 bars or more. Crystallization can be induced either by introducing temperature variations, or by changing the composition of the coexisting aqueous vapor phase under isobaric, isothermal conditions. The system CaO-MgO-CO_2-H_2O is used to show that doped calcite crystals, Ca_xR_(1-x)CO_3, could be precipitated, with precisely controlled compositions, from melts in the system CaO-RO-CO_2-H_2O. Apatite phase relations are also presented.", "doi": "10.1111/j.1151-2916.1967.tb14969.x", "issn": "0002-7820", "publisher": "Wiley-Blackwell", "publication": "Journal of the American Ceramic Society", "publication_date": "1967-01", "series_number": "1", "volume": "50", "issue": "1", "pages": "43-46" }, { "id": "authors:8gs9j-99m72", "collection": "authors", "collection_id": "8gs9j-99m72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-081338893", "type": "article", "title": "Experimental Petrology: An Indoor Approach to an Outdoor Subject", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental petrology is concerned with the laboratory\nstudy of reactions designed to elucidate petrological\nprocesses. The term includes experiments dealing\nwith the physical properties or physical chemistry\nof minerals, rocks, rock melts, or of vapors, gases or solutions\ncoexisting with solid or molten materials. Much of\nthe impetus for experimental petrology has come from\nthe efforts of geologists to understand the origin of igneous\nand metamorphic rocks. These rocks provide \"fossil\" records of the processes involved in the development of\nmountain ranges and the formation of continents, processes\nwhich are surface manifestations of changes occurring\nwithin the mantle. On the basis of standard\ngeological, structural, and petrological investigations of\nrocks exposed at the surface of the earth, petrologists\npropose hypotheses about the processes involved in the\norigin of rocks at depth. Experimental petrology provides\none means of testing the relative merits of various\nhypotheses by permitting the reproduction in the laboratory\nof high pressures and temperatures similar to\nthose involved in the natural processes.", "issn": "0022-1368", "publisher": "Association of Geology Teachers", "publication": "Journal of Geological Education", "publication_date": "1966-06", "series_number": "3", "volume": "14", "issue": "3", "pages": "93-97" }, { "id": "authors:2yh62-6z429", "collection": "authors", "collection_id": "2yh62-6z429", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-080202405", "type": "article", "title": "Experimental Petrology and the Orogenic Cycle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Much of the impetus for the development of experimental petrology has\ncome from the efforts of geologists to understand the origin of igneous and\nmetamorphic rocks. These rocks provide fossil records of the processes\ninvolved in the development of mountain ranges and the formation of continents,\nprocesses which are surface manifestations of changes occurring\nwithin the mantle. On the basis of standard geological, structural, and petrological\ninvestigations, petrologists propose hypotheses about the processes\ninvolved in the origin of the rocks at depth. Experimental petrology provides\none means of testing the various hypotheses by permitting the reproduction\nin the laboratory of high pressures and temperatures similar to those involved\nin the natural processes.\nThe orogenic cycle is a concept which provides a convenient framework\nfor a review of the applications of experimental petrology. Major geological\nprocesses associated with the cycle include the sinking and uplift of geosynclinal\nbelts, magma generation, and metamorphism. The results of experimental\npetrology provide limits for the conditions at depth during some of\nthese processes.", "doi": "10.1111/j.2164-0947.1966.tb02388.x", "issn": "0028-7113", "publisher": "New York Academy of Sciences", "publication": "Transactions of the New York Academy of Sciences", "publication_date": "1966-05", "series_number": "7", "volume": "28", "issue": "7", "pages": "837-844" }, { "id": "authors:g3tcp-t4450", "collection": "authors", "collection_id": "g3tcp-t4450", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-091148930", "type": "article", "title": "The system CaO-SiO_2-CO_2-H_2O. II\u2014The petrogenetic model", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Haas", "given_name": "J. L., Jr.", "clpid": "Haas-J-L-Jr" } ], "abstract": "In each of the three isobaric invariant reactions below 900\u00b0 C on the vapor-saturated liquidus surface of the system CaO-SiO_2-CO_2-H_2O at 1 kilobar pressure, the vapor phase is extremely rich in H_2O. The effect of adding H_2O to the vapor phase on the temperatures of successive decarbonation reactions in the system CaO-SiO_2-CO_2 (involving the formation of wollastonite, spurrite and dicalcium silicate) is illustrated in the petrogenetic model. At 1 kilobar pressure the primary fields of spurrite and calcite on the vapor-saturated liquidus surface are separated by a field boundary extending down to a peritectic at 677\u00b0 C. Examination of the melting reactions and the decarbonation reactions plotted in the petrogenetic model shows that the latter intersect the former with increasing pressure, and the first result of this at pressures above 1 kilobar is that a primary field for wollastonite replaces the peritectic on the vapor-saturated liquidus surface. Then, calcite and wollastonite can be co-precipitated from a liquid down to temperatures below 700\u00b0 C. Applications to carbonatites are discussed briefly. If an igneous intrusion gives off enough H_2O during crystallization to flush CO_2 gas from the pores of a siliceous limestone in contact with it, partial melting of the limestone could conceivably occur. This possibility should be considered seriously in studies of thermal metamorphism.", "doi": "10.1016/0016-7037(66)90063-9", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1966-05", "series_number": "5", "volume": "30", "issue": "5", "pages": "525-543" }, { "id": "authors:yzyzc-qye80", "collection": "authors", "collection_id": "yzyzc-qye80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-141512270", "type": "article", "title": "Liquid immiscibility in the system Na_2O-Al_2O_3-SiO_2-CO_2 at pressures to 1 kilobar", "author": [ { "family_name": "van Groos", "given_name": "A. F. Koster", "clpid": "van-Groos-A-F-K" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "A liquid miscibility occurs within the Quaternary system, Na_2O-Al_2O_3-SiO_2-CO_2 between Na_2 CO_3-rich liquids and NaAlSi_3O_8-rich liquids. The vapor-saturated liquidus surface does not intersect the miscibility gap at low pressures, but with increasing pressure it undergoes two discontinuous shifts toward the CO_2 apex of the tetrahedron, produced by carbonation reactions in the system Na_2O-SiO_2-CO_2. These position changes cause the vapor-saturated surface to intersect the miscibility gap. At 1 kilobar pressure on the join NaAlSi_3O_8-Na_2CO_3-CO_2, the two-liquid field occurs at temperatures above 870 degrees C.", "doi": "10.2475/ajs.264.3.234", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1966-03", "series_number": "3", "volume": "264", "issue": "3", "pages": "234-255" }, { "id": "authors:z78zt-12e53", "collection": "authors", "collection_id": "z78zt-12e53", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-150333701", "type": "article", "title": "Acceptance of the 1965 Mineralogical Society of America Award", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "When the time came to ask someone to introduce me, I was sorry to\nlearn that Dr. O. F. Tuttle could not oblige, because he was the obvious\nchoice, but I was pleased when Dr. R. H. Jahns came to my rescue. I\nknow that my new colleagues in Chicago (with three MSA Awards in the\ndepartment now) do not mind me describing this as a Penn State Award,\nand I am sure that Dr. Jahns' new colleagues at Stanford do not mind me\nreclaiming him for Penn State on this occasion. When I learned at the\nlast GSA meeting that I had been erected as the 1965 recipient of the\nMSA Award I was overcome with the shock of surprise and pleasure. The\nshock has abated, but I still cannot express my feelings adequately I can\nonly assure the nominating committee and the council that this honor is\ngreatly appreciated-very greatly appreciated. Then, like the previous\nrecipients, I take pleasure in thanking my teachers and associates, and in\ntelling you a little about them.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1966-03", "series_number": "3-4", "volume": "51", "issue": "3-4", "pages": "557-559" }, { "id": "authors:9m4d7-20587", "collection": "authors", "collection_id": "9m4d7-20587", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-091149199", "type": "article", "title": "Melting relationships in the system CaO-MgO-SiO_2-H_2O at 1 kilobar pressure", "author": [ { "family_name": "Franz", "given_name": "G. W.", "clpid": "Franz-G-W" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Solid-liquid-vapor phase relationships in the system CaO-MgO-SiO_2-H_2O have been determined at 1 kilobar pressure using the quench technique in cold-seal pressure vessels. The phase fields intersected by the composition joins Ca(OH)_2-Mg_2SiO_4 and Ca(OH)_2-MgSiO_3 have been delineated in the temperature range 700\u2013950\u00b0C. From these results and from previous work in the bounding systems, a schematic diagram for the phase relationships on the vapor-saturated liquidus surface has been prepared. A thermal divide exists on this surface, corresponding to the melting of mixtures on the join Ca_2SiO_4-MgO in the presence of H_2O vapor. Original liquids with compositions on the SiO_2 side of the divide yield anhydrous crystalline phases and vapor on fractional crystallization, whereas original liquids with compositions on the CaO side of this divide yield hydrated crystalline phases (calciochondrodite and portlandite) plus vapor. The estimated compositions of isobaric invariant liquids at 1 kilobar pressure for the reactions: portlandite + calciochondrite + periclase + vapor \u21cc liquid, at 725\u00b0C calciocondrite + periclase + vapor \u21cc dicalcium silicate + liquid, at 875\u00b0C, are Ca(OH)_2\u221292.7%, Ca_2SiO_4\u22124.3%, MgO\u22122.5%, H_2O\u22120.5%, and Ca(OH)_2\u221262.1%, Ca_2SiO_4\u221225.6%, MgO\u221211.3%, H_2O\u22121.0%. These results provide a basis for interpretation of the phase relationships in the more complex system CaO-MgO-SiO_2-CO_2-H_2O which have bearing on the petrogenetic relationships between kimberlites and carbonatites.", "doi": "10.1016/0016-7037(66)90088-3", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1966-01", "series_number": "1", "volume": "30", "issue": "1", "pages": "9-22" }, { "id": "authors:3n6rs-s5a41", "collection": "authors", "collection_id": "3n6rs-s5a41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160307-134420161", "type": "article", "title": "Fractional Crystallization in the \"Carbonatite Systems\" CaO-MgO-CO\u2082-H\u2082O and CaO-CaF\u2082-P\u2082O\u2085-CO\u2082-H\u2082O", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Biggar", "given_name": "G. M.", "clpid": "Biggar-G-M" } ], "contributor": [ { "family_name": "Naidu", "given_name": "P. R. J.", "clpid": "Naidu-P-R-J" } ], "abstract": "Many carbonatite masses exhibit inhomogeneities on both large and small scales. Evidence for\nlarge scale differentiation is offered by the successive intrusion of s\u00f6vite, ankeritic s\u00f6vite, and finally\nsiderite carbonatites at complexes such as Chilwa Island. On a smaller scale, the segregation of minerals\nis illustrated by the development of apatite-rich bands and lenses in the carbonatite. In the system\nCaO-MgO-FeO-H_2O, the minerals calcite, portlandite, periclase, and iron oxide are stable on the\nvapor-saturated liquidus above 600\u00b0C at pressures below about 900 bars, with brucite, dolomite (or\nankerite), and sidcrite appearing on this liquidus only at successively higher pressures. In the system\nCaO-CaF_2-P_2O_5-CO_2-H_2O, apatite and calcite may crystallize simultaneously through a wide range of\npressures and temperatures (as low as 575\u00b0C). However, any liquid containing initially more than a\nsmall percentage of P_2O_5 precipitates apatite before calcite. The synthetic carbonatite magmas are very\nfluid, and crystal settling occurs within a few minutes. Paths of crystallization and the sequence of\nminerals precipitated are dependent upon several variables, including changes in temperature, in\npressure, and in the composition of the vapor phase (CO_2-H_2O) in equilibrium with liquid and crystals.\nIt can be shown from the phase relationships in these systems that fractional crystallization of synthetic\ncarbonatite magmas is capable of producing differentiation sequences similar to those occurring at\nChilwa Island and elsewhere.", "issn": "0579-5559", "publisher": "International Mineralogical Association", "publication": "Papers and proceedings of the ... general meeting - International Mineralogical Association", "publication_date": "1966", "volume": "1964", "pages": "92-105" }, { "id": "authors:44pef-zps08", "collection": "authors", "collection_id": "44pef-zps08", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160302-133725879", "type": "article", "title": "Experimental Data Bearing on the Petrogenetic Links between Kimberlites and Carbonatites", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "contributor": [ { "family_name": "Naidu", "given_name": "P. R. J.", "clpid": "Naidu-P-R-J" } ], "abstract": "The genetic relationships among kimberlites, carbonatites, and associated alkaline igneous rocks\nare being investigated by phase equilibrium studies in a number of silicate-carbonate systems, with\nspecial emphasis on liquidus studies. The precipitation of calcite from melts in the system CaO-CO_2-\nH_2O at temperatures near 650\u00b0, through a wide pressure range, was regarded by Wyllie and Tuttle as\nexperimental verification for the magmatic origin of carbonatites. Addition of silicates has yielded significant\nresults in the systems: CaO-SiO_2-CO_2-H_2O (J . L. Haas), CaO-MgO-SiO_2-CO_2-H_2O (G. W. Franz),\nalbite-nepheline-CaCO_3-Ca(OH_2-H_2O (D . H. Watkinson), and a northitc-albite-Na_2-CO_3-H_2O (A. F.\nKoster van Groos). The heterogeneous phase relationships in these systems indicate that a variety of\npetrogenetic processes may be effective. There is a persistent thermal barrier on the liquidus of several\nsystems which suggests that normal peridotite magmas are incapable of yielding a residual lime-rich\ncarbonatite magma by fractional crystallization. However, there is evidence in other systems that\ncrystallization of an alkaline magma may yield a residual carbonatite magma. Liquid immiscibilily has\nbeen discovered between some silicate melts and sodium carbonate melts, adding support to the suggestion\nthat carbonatite magmas may be derived as immiscible fractions from parent alkali peridotite\nmagmas. This fact also provides support for the hypothesis that a primary alkali carbonatite magma\ncould form and persist without significant contamination by silicates until conditions (pressure, temperature,\nor composition) were reached where the immiscibility relationship ceased to exist. Mineral\nassemblages in the systems studied are closely comparable with those in many carbonatitc complexes.\nThe wide distribution of melilite is notable.", "issn": "0579-5559", "publisher": "International Mineralogical Association", "publication": "Papers and proceedings of the ... general meeting - International Mineralogical Association", "publication_date": "1966", "volume": "1964", "pages": "67-82" }, { "id": "authors:mrg97-kyb75", "collection": "authors", "collection_id": "mrg97-kyb75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-153203458", "type": "article", "title": "DTA and quenching methods in the system CaO-CO_2-H_2O", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Raynor", "given_name": "E. J.", "clpid": "Raynor-E-J" } ], "abstract": "Harker (1964) recently described a simple technique for differential\nthermal analysis in closed systems containing volatile components under\npressure, which promises to be of great utility. He contrasted the reaction\ntemperatures recorded in his preliminary studies with those reported in\nthe same systems by quenching techniques, and he noted some rather\nlarge temperature discrepancies. This led him to conclude that the accuracy of the quenching technique in systems where the liquid phase\ncannot be quenched to a glass \"is often somewhat low and sometimes\nquite misleading.\" However, if the melting temperature of portlandite\nrecorded by Wyllie and Tuttle (1960) is corrected as shown by Gittins\nand Tuttle (1964), the results obtained by DTA and quenching techniques\nare almost identical, and Harker's concern for the validity of the\nquenching technique becomes unnecessary, in this system at any rate.\nThis note contains revised values for melting reactions in the system CaO-CO_2H_2O measured by one of us (EJR) using the quench technique,\nand a discussion of this technique and DTA by the other (PJW).", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1965-11", "series_number": "11-12", "volume": "50", "issue": "11-12" }, { "id": "authors:20bgn-m2554", "collection": "authors", "collection_id": "20bgn-m2554", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-091148681", "type": "article", "title": "The system CaO-SiO_2-CO_2-H_2O: 1. Melting relationships with excess vapor at 1 kilobar pressure", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Haas", "given_name": "J. L., Jr.", "clpid": "Haas-J-L-Jr" } ], "abstract": "Solid-liquid-vapor phase equilibria have been determined for parts of the system CaO-SiO_2-CO_2-H_2O by delineating the phase fields intersected by the composition join CaCO_3-Ca(OH)_2-(SiO_2 + 4.3 weight per cent H_2O) at 1 kilobar pressure between 600\u00b0C and 975\u00b0C. The phases encountered were: dicalcium silicate (C_2S), Ca_2SiO_4; calcite (CC), CaCO_3; portlandite (CH), Ca(OH)_2; spurrite (Sp), Ca_5(SiO_4)_2(CO_3)_2; caleiochondrodite (Ch), Ca_5(SiO_4)_2(OH)_2; liquid (L), with composition remaining close to the plane Ca_2SiO_4-CaCO_3-Ca(OH)_2; vapor (V), with composition ranging between CO_2 and H_2O. At the pressure of 1 kilobar, the following ternary univariant reactions, (2) and (3), and quaternary univariant reactions, (6), (7) and (8). were established at the temperatures indicated: (2) CH + Ch + V \u21cc L(E_2) at 774 \u00b1 10\u00b0C; (3) Ch + V \u21cc C_2S + L(P_3) at 955 \u00b1 10\u00b0C; (6) CC + CH + Ch + V \u21cc L(E_6) at 637 \u00b1 10\u00b0C; (7) CC + Ch + V \u21cc Sp + L(P_7) at 677 \u00b1 10\u00b0C; (8) Sp + Ch \u21cc C_2S + L(P_8) + V at 860 \u00b1 10\u00b0C. The vapor in each reaction is high in H_2O content. From these results and other published data a schematic equilibrium diagram for the whole system is constructed. A large field for spurrite extends down to 677\u00b0C on the vapor-saturated liquidus surface but wollastonite is not stable in equilibrium with both liquid and vapor below 1000\u00b0C at this pressure. The plane Ca_2SiO_4-CO_2-H_2O is a thermal divide; original liquids containing more SiO_2 than this plane yield only silicates and vapor on crystallization, whereas original liquids containing less SiO_2 than this plane can yield low temperature liquids precipitating hydrated and carbonated phases (synthetic carbonatite magmas). Applications to carbonatites and the thermal metamorphism of silicious limestones are discussed briefly.", "doi": "10.1016/0016-7037(65)90084-0", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "1965-08", "series_number": "8", "volume": "29", "issue": "8", "pages": "871-892" }, { "id": "authors:e453t-pyp78", "collection": "authors", "collection_id": "e453t-pyp78", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-074548525", "type": "article", "title": "Zoned magnetite and platy magnetite in Cornwall type ore deposits", "author": [ { "family_name": "Davidson", "given_name": "A.", "clpid": "Davidson-A" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Eighteen selected specimens from the Cornwall type ore deposits of\nPennsylvania were studied by optical examination of polished sections and\nby means of an electron microprobe X-ray analyzer (without calibration).\nThe elements Ti, Si, V, Mn, Co, and Ni occur in the magnetite crystals\nin very low concentrations with little variation. In zoned magnetite\ncrystals, yellowish color bands parallel to crystal faces are marked by\nincreased concentrations of Al and Mg. Some magnetite crystals contain\nminute oriented inclusions whose concentration decreases outwards; the\nMg concentration decreases outwards as well, correlating with the variation\nin concentration of the inclusions. Platy magnetite crystals, pseudomorphs\nafter hematite, contain cores of lighter colored magnetite; the outer\nmagnetite contains slightly less Fe and slightly more impurities in solid\nsolution than the inner magnetite core that replaces hematite.", "doi": "10.2113/gsecongeo.60.4.766", "issn": "0361-0128", "publisher": "Society of Economic Geologists", "publication": "Economic Geology", "publication_date": "1965-06", "series_number": "4", "volume": "60", "issue": "4", "pages": "766-771" }, { "id": "authors:fjv22-48345", "collection": "authors", "collection_id": "fjv22-48345", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-075017915", "type": "article", "title": "A Modification of the Geosyncline and Tectogene Hypothesis", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Intersections may exist between a zone of chemical discontinuity (basalt\u2014feldspathic periodtite or eclogite\u2014garnet peridotite) and a phase transition zone (basalt\u2014eclogite or feldspathic peridotite to garnet peridotite) at about the depth of the continental M-discon-tinuity. Variations in depth to the chemical discontinuity and in the positions of isogeotherms produce flexibility in erogenic models. Intersections between the two zones at depth could be reflected at the surface by major fault zones separating large structural blocks of different elevations. The effects of such intersections on the conventional hypothesis for the development of tectogenes, geosynclines, and mountains are considered. The intersections could provide a beginning and an end to the more vigorous changes in surface level occurring during an orogenic cycle.", "doi": "10.1017/S0016756800053267", "issn": "0016-7568", "publisher": "Cambridge University Press", "publication": "Geological Magazine", "publication_date": "1965-06", "series_number": "03", "volume": "102", "issue": "03", "pages": "231-245" }, { "id": "authors:skq5v-86a04", "collection": "authors", "collection_id": "skq5v-86a04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160119-141431566", "type": "article", "title": "Experimental petrology; a laboratory approach to geology", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The geologist, as a student of the earth, is surrounded by his work. While fishing in a mountain stream, he realizes that the sheltered pool into which he is casting exists only because the large, rounded boulders damming back the water have been piled there by rushing water flowing down the hillside. This recalls the vast quantities of soil and rock which are transported by water. Much of this debris is deposited in the sea. At the beach one may see the waves shaping the shoreline as each breaker shifts the grains of sand while, just down the coast, the waves in a more ferocious mood hammer away at the base of the rocky cliffs they have carved. After a season or two of drought, when wells go dry and water becomes a topic for newspaper editorials, one may remember that whereas much water flows clown to the ocean, other water percolates below the surface and becomes distributed in a manner which is controlled by the attitude and properties of the rocks as well as by the surface relief. Whether traveling by car or railroad, one passes through artificial valleys cut by engineers, which expose the rock beneath the layer of surface soil. As a geologist one is aware of the differing properties of rocks in different places. Some rocks are tough and uniform, appearing as high walls alongside the road or track; others are soft and easily fragmented, and the slopes of these are more gentle lest the rocks slide down and cause damage.", "issn": "0097-2320", "publisher": "Pennsylvania State University", "publication": "Mineral Industries", "publication_date": "1965-06", "series_number": "9", "volume": "34", "issue": "9", "pages": "1-7" }, { "id": "authors:kkkpk-dkq51", "collection": "authors", "collection_id": "kkkpk-dkq51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160122-073544097", "type": "article", "title": "Water-spouts on the Britannia Gletscher, north-east Greenland", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Wiseman's (1963) letter to this Journal describing a water-spout on the Aletsch Gletscher reminded\nme of the water-spouts encountered by members of the British North Greenland Expedition (Simpson,\n1955) near the snout of the Britannia Gletscher in the summer of 1954, and prompted me to exhume\ntwo photographs from my files (Figs. 1 and 2). These water-spouts were not intermittent like those\ndescribed by Wiseman (1963) and Rucklidge (1956), but were continuous gushers lasting for several\ndays, and forming an integral part of the drainage pattern of the glacier. They are thus more akin to\nthe spouts described by Glen (1941), who stressed the role of crevasses in englacial and subglacial\ndrainage and stated that sometimes the water carried in this way from higher levels \"attains such a\npressure that it literally bursts its way through the ice, sending up a small water-spout which may\ncontinue for as a long as an hour, then dying down into a more gentle fountain\".", "issn": "0022-1430", "publisher": "International Glaciological Society", "publication": "Journal of Glaciology", "publication_date": "1965-02", "series_number": "40", "volume": "5", "issue": "40", "pages": "521-523" }, { "id": "authors:sv168-t2s18", "collection": "authors", "collection_id": "sv168-t2s18", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160119-141734442", "type": "article", "title": "Melting Relationships in the System CaO-MgO-CO_2-H_2O, with Petrological Applications", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Phase relationships on the vapor-saturated liquidus surface in the system CaO-MgO-CO_2-H_2O have been deduced from data in the systems CaO CO_2-H_2O, CaO-MgO-CO_2, and MgO-CO_2-H_2O, and from preliminary experiments in the quaternary system. These are illustrated in composition tetrahedra, and in isobaric sections through the petrogenetic model. The univariant PT curve for the beginning of melting lies between 625\u00b0 C and 600\u00b0 C in the pressure range 10 bars to 4 kilobars, in the presence of a vapor phase rich in H_2O. The curve is divided into three sections by two invariant points, each section having a different primary magnesian phase involved in the melting reaction. Periclase occurs on the low-pressure section (less than about 1 kilobar), and with increasing pressure first brucite and then dolomite become stable on the liquidus. The pressure of the second invariant point, above which dolomite is stable on the liquidus, is not known. The effect of FeO as an additional component is considered. Processes of crystallization resulting from changes in temperature, in pressure, and in the composition of the vapor phase are discussed. These processes are applied to the crystallization and differentiation of carbonatite magmas, and the reverse processes involving fusion are applied to the metamorphism of dolomites. Crystallization differentiation of a carbonatite magma could produce the sequence of intrusion observed at some carbonatite complexes: calcitic s\u00f6vite, followed by ankeritic s\u00f6vite, and finally sideritic carbonatite. Partial melting may occur during the thermal metamorphism of dolomites, but melting is unlikely during regional metamorphism.", "doi": "10.1093/petrology/6.1.101", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1965", "series_number": "1", "volume": "6", "issue": "1", "pages": "101-123" }, { "id": "authors:4yny0-3r555", "collection": "authors", "collection_id": "4yny0-3r555", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-082531219", "type": "article", "title": "The Limestone Assimilation Hypothesis", "author": [ { "family_name": "Watkinson", "given_name": "David H.", "clpid": "Watkinson-D-H" }, { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "In a recent communication describing the synthesis of\nfeldspathoids by feldspar-carbonate reactions, R. D.\nSchuiling discussed the limestone-syntexis hypothesis,\nwhich proposes that rock-types under-saturated in silica\ncan form from silica-over-saturated magmas by assimilation\nof limestone, and he stated that, from a physico-chemcial\npoint of view, there was no essential difference\nbetween this process and one involving the assimilation of\nsialic material by a carbonatite magma. He remarked that:\n\"Nobody, however, seems to have tried to verify experimentally\nsuch proposed processes\". The purposes of this\ncommunication are: (1) to direct attention to an extensive\nseries of experiments by Stansfield which were aimed\ndirectly at testing assimilation hypotheses, and which\nincluded investigation of the extent and products of\nassimilation of limestone by various igneous melts;\n(2) to outline some of our own experiments which are\nconcerned with the origin of carbonatites and associated\nalkalic rocks and, inevitably therefore, with the limestone\nassimilation hypothesis as well; (3) to comment on some\npoints of Schuiling's communication.", "doi": "10.1038/2041053a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1964-12-12", "series_number": "4963", "volume": "204", "issue": "4963", "pages": "1053-1054" }, { "id": "authors:ne848-b9950", "collection": "authors", "collection_id": "ne848-b9950", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160202-110922747", "type": "article", "title": "Experimental investigation of silicate systems containing two volatile components; Part 3, The effects of SO_3, P_2O_5, HCl, and Li_2O, in addition to H_2O, on the melting temperatures of albite and granite", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "Mixtures composed of 50 weight percent of silicate (albite, granite, or\nglass) and 50 weight percent of aqueous solutions of H_2SO_4, H_3PO_4, HCl, and LiOH were\nsealed in gold capsules and held at various temperatures at a constant pressure of 2750\nbars. In the presence of H_2O alone at this pressure, albite melts at 810\u00b0C and granite begins\nto melt at 665\u00b0C. In the presence of aqueous solutions containing 5 weight percent\nof the second volatile component the temperature of beginning of melting of albite is\n710\u00b0C for SO_3, 660\u00b0C for P_2O_5, and 708\u00b0C for HCl; and that of granite is 665\u00b0C for SO_3,\n645\u00b0C for P_2O_5, 680\u00b0C for HCl, and 575\u00b0C for LiO_2. Applications of these experimental\nresults, together with results obtained previously for the volatile components HF, NH_3,\nand CO_2, are briefly discussed in connection with the origin of granites, pegmatites, alumina-\nundersaturated alkaline rocks, and thermal waters of volcanic origin.", "doi": "10.2475/ajs.262.7.930", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1964-09", "series_number": "7", "volume": "262", "issue": "7", "pages": "930-939" }, { "id": "authors:vx150-ae405", "collection": "authors", "collection_id": "vx150-ae405", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-112226681", "type": "article", "title": "The quenching technique in non-quenchable systems: a discussion concerning the alleged thermal decomposition of portlandite at high pressures", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "With reference to data on the thermal decomposition of portlandite published in a paper by C.W.F.T. Pistorius, confirms the validity of the quenching technique used for high-pressure studies of phase relationships in the CaO-CO_2-H_2O system as applied to nonquenchable systems containing volatile components, and reconfirms the conclusion that portlandite does not dissociate at pressures greater than 100 bars, but melts incongruently at low pressures and congruently at slightly higher pressures.", "doi": "10.2475/ajs.261.10.983", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1963-12", "series_number": "10", "volume": "261", "issue": "10", "pages": "983-988" }, { "id": "authors:7s46w-qdf83", "collection": "authors", "collection_id": "7s46w-qdf83", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160331-082400866", "type": "article", "title": "The Mohorovi\u010di\u0107 Discontinuity and the Orogenic Cycle", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The following report, by Peter J. Wyllie,\nDepartment of Geochemistry and Mineralogy,\nPennsylvania State University, is based\non a paper presented by the author at the\nSecond Western National Meeting of the\nAmerican Geophysical Union, held at Stanford\nUniversity, December 1962. A similar,\nmore-detailed version of this paper has\nbeen published in the Journal of Geophysical\nResearch, August 1, 1963. The version\npresented below includes an enlarged discussion\nof possible applications to the orogenic\ncycle; essentially the same version\nhas also been issued as Pennsylvania State\nUniversity Mineral Industries Contribution\nNo. 62-91.", "doi": "10.1029/TR044i004p01053", "issn": "0096-3941", "publisher": "American Geophysical Union", "publication": "Eos", "publication_date": "1963-12", "series_number": "4", "volume": "44", "issue": "4", "pages": "1064-1072" }, { "id": "authors:9gt7v-3bw31", "collection": "authors", "collection_id": "9gt7v-3bw31", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-080632078", "type": "article", "title": "Experimental Data bearing on the Role of Liquid Immiscibility in the Genesis of Carbonatites", "author": [ { "family_name": "Koster Van Gross", "given_name": "A. F.", "clpid": "Koster-Van-Gross-A-F" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The recognition of low-temperature melts in the system CaO\u2014CO_2\u2014H_2O has opened a new field of heterogeneous phase equilibrium studies in systems containing both water and carbon dioxide, the volatiles most abundant in the Earth's crust and among the most important in igneous and metamorphic processes. Liquids in this system may be regarded as simplified carbonatite magmas. The petrogenetic relationships between carbonatite magmas and the associated alkaline rocks can be examined by determining the phase relationships in systems containing CaO\u2014CO_2\u2014H_2O and silicate minerals. In a programme supported by the National Science Foundation, we have been investigating selected portions of complex systems in order to test the feasibility of the petrogenetic relationships which have been proposed on the basis of petrological investigations.", "doi": "10.1038/199801a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1963-08-24", "series_number": "4895", "volume": "199", "issue": "4895", "pages": "801-802" }, { "id": "authors:fsghx-0jg26", "collection": "authors", "collection_id": "fsghx-0jg26", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141107-143542366", "type": "article", "title": "The nature of the Mohorovicic discontinuity, A compromise", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "The available experimental data and steady-state calculations make it difficult to explain the M discontinuity beneath both oceans and continents on the basis of the same phase change. The oceanic M discontinuity may be a chemical discontinuity between basalt and peridotite, and a similar chemical discontinuity may thus be expected beneath the continents. Since available experimental data place the basalt-eclogite phase change at about the same depth as the continental M discontinuity, intersections may exist between a zone of chemical discontinuity and a phase transition zone, the transition being either basalt-eclogite or feldspathic peridotite-garnet peridotite. Detection of the latter transition by seismic techniques may be difficult. The M discontinuity could therefore represent the basalt-eclogite phase change in some localities (e.g. mountain belts) and the chemical discontinuity in others (e.g. oceans and continental shields). Variations in the depth to the chemical discontinuity and in the positions of geoisotherms produce great flexibility in orogenetic models. Intersections between the two zones at depth could be reflected at the surface by major fault zones separating large structural blocks of different elevations.", "doi": "10.1029/JZ068i015p04611", "issn": "0148-0227", "publisher": "American Geophysical Union", "publication": "Journal of Geophysical Research", "publication_date": "1963-08-01", "series_number": "15", "volume": "68", "issue": "15", "pages": "4611-4619" }, { "id": "authors:bbrkk-mtc54", "collection": "authors", "collection_id": "bbrkk-mtc54", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-084249856", "type": "article", "title": "The Petrogenetic Model, an Extension of Bowen's Petrogenetic Grid", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Bowen's petrogenetic grid is a PT projection containing univariant curves for decarbonation, dehydration, and solid-solid reactions, with vapour pressure (P_f) equal to total pressure (P_s). Analysis of experimental data in the system MgO\u2013CO_2\u2013H_2O leads to an expansion of this grid. Three of the important variables in metamorphism when P_f = P_s are P, T, and variation of the pore fluid composition between H_2O and CO_2. These can be illustrated in a three-dimensional petrogenetic model; one face is a PT plane for reactions occurring with pure H_2O, and the opposite face is a similar plane for reactions with pure CO_2; these are separated by an axis for pore fluid composition varying between H_2O and CO_2. Superposition of the PT faces of the model provides the petrogenetic grid. The reactions within the model are represented by divariant surfaces, which may meet along univariant lines. For dissociation reactions, the surfaces curve towards lower temperatures as the proportion of non-reacting volatile increases, and solid-solid reaction surfaces are parallel to the vapour composition axis and perpendicular to the PT axes. The relative temperatures of reactions and the lines of intersections of the surfaces can be illustrated in isobaric sections. Isobaric sections are used to illustrate reactions proceeding at constant pressure with (1) pore fluid composition remaining constant during the reaction, with temperature increasing (2) pore fluid composition changing during the reaction, with temperature increasing, and (3) pore fluid changing composition at constant temperature. The petrogenetic model provides a convenient framework for a wide range of experimental data.", "doi": "10.1017/S0016756800059859", "issn": "0016-7568", "publisher": "Cambridge University Press", "publication": "Geological Magazine", "publication_date": "1962-11", "series_number": "6", "volume": "99", "issue": "6", "pages": "558-569" }, { "id": "authors:y4y35-ekn37", "collection": "authors", "collection_id": "y4y35-ekn37", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-111616589", "type": "article", "title": "Carbonatitic Lavas", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "Recently, von Knorring and du Bois described a vesicular lava of high carbonate content from western Uganda which shows close geochemical affinities with intrusive carbonatites. They stated: \"It must be emphasized that the lavas examined are fresh and unaltered and that the carbonated nature cannot be attributed to alteration after solidification\". Descriptions of extrusive equivalents of carbonatites are rare, but two other examples have been reported recently from Africa. Bailey concluded that certain carbonate-rich tuffs in Northern Rhodesia were primary, and not alteration products of more normal rocks. On p. 58 of his report, he wrote: \"Indigestible though the fact may be to some philosophical systems\u2014the pyroclastics around the Rufunsa vents are effusive carbonatite\". Reference is made, in both papers, to the 1954 eruption of Oldonyo Lengai in Tanganyika, during which showers of dust and ashes, largely composed of calcium and sodium carbonates, were observed to fall on the flanks of the volcano.", "doi": "10.1038/1941269a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1962-06-30", "series_number": "4835", "volume": "194", "issue": "4835", "pages": "1269" }, { "id": "authors:08jxv-msb12", "collection": "authors", "collection_id": "08jxv-msb12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-134725243", "type": "article", "title": "The Effect of 'Impure' Pore Fluids on Metamorphic Dissociation Reactions", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Comparison of experimental data from the systems MgO-CO_2-H_2O (closed) and MgO-CO_2-A (simulating an open system) shows that the effects of H_2O and A on the dissociation of magnesite are almost identical; both behave as inert components reducing the partial pressure of CO_2. The dissociation temperature at constant total pressure is lowered according to the proportion of inert volatiles in the initial vapour phase. The dissociation is completed at one temperature (univariant) in an open system but in a closed system it proceeds through a temperature interval (divariant) because the vapour phase changes composition. The amount of dissociation remains small until the upper limit of the interval is reached. More complex dissociation reactions in the systems CaO-MgO-CO_2-H_2O and CaO-SiO_2-CO_2-H_2O are described; they follow similar patterns. Under closed or partially open metamorphic conditions non-reacting pore fluid components (inert) have to be treated as one additional component for application of the mineralogical phase rule. Comparison of the pattern of metamorphic parageneses with the patterns of reactions occurring under known experimental conditions may provide information about metamorphic processes. Metamorphic reactions can be represented within a petrogenetic model with axes P, T, and pore fluid composition varying between H_2O and CO_2.", "doi": "10.1180/minmag.1962.033.256.03", "issn": "0026-461X", "publisher": "Mineralogical Society", "publication": "Mineralogical Magazine", "publication_date": "1962-03", "series_number": "256", "volume": "33", "issue": "256", "pages": "9-25" }, { "id": "authors:zvyp7-vcz72", "collection": "authors", "collection_id": "zvyp7-vcz72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-141041508", "type": "article", "title": "VIII.\u2014The Petrology of Picritic Rocks in Minor Intrusions\u2014a Picrite Sill on the Island of Soay (Hebrides)", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Drever", "given_name": "H. I.", "clpid": "Drever-H-I" } ], "abstract": "A Small picrite sill of critical significance is examined in detail, from top to bottom, with particular reference to the distribution and crystallization of the olivine. Statistical evaluation of the sizes of olivine crystals establishes a gradation from large phenocrysts to small groundmass crystals. The micrometric data indicate that, while the feldspar content has remained constant, there is an inverse relationship between the distribution of olivine and pyroxene. This relationship, viewed in conjunction with the common tendency toward skeletal crystallization of the olivine and its gradation in size, amounts to substantial evidence that much of the olivine rapidly crystallized at the time when the sill was emplaced. At a few places, the sandstones and grits, into which the sill has been intruded, have been fused. Where it has penetrated a dolerite dyke along its direction of strike, a non-porphyritic facies, with very much less olivine, is associated with xenoliths of peridotite and of fused sandstone. It is inferred, from the field relationships, that this non-porphyritic facies was intruded as a liquid, containing xenoliths, in advance of the picrite. The chemical composition of this liquid is more calcic than basalt. It is concluded that this earlier calcic liquid was followed by a later magnesian (picritic) liquid and that these liquids have probably a deep-seated genetic relationship with feldspathic peridotite. Further research must be directed toward investigating this relationship both experimentally and in picrite\u2014peridotite rock associations.", "doi": "10.1017/S0080456800012497", "issn": "0080-4568", "publisher": "Royal Society of Edinburgh", "publication": "Transactions of the Royal Society of Edinburgh", "publication_date": "1962-01", "series_number": "08", "volume": "65", "issue": "08", "pages": "155-177" }, { "id": "authors:w8rcg-sp195", "collection": "authors", "collection_id": "w8rcg-sp195", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-134414382", "type": "article", "title": "The Habit of Apatite in Synthetic Systems and Igneous Rocks", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Cox", "given_name": "K. G.", "clpid": "Cox-K-G" }, { "family_name": "Biggar", "given_name": "G. M.", "clpid": "Biggar-G-M" } ], "abstract": "Apatite crystals co-existing with liquid or with vapour in the system CaO-CaF_2-P_2O_6-H_2O-CO_2 are equant whereas those precipitated from a liquid during a quench are greatly elongated parallel to the c-axis and they exhibit skeletal forms. Basic rocks in the Karroo volcanic succession of Southern Rhodesia contain apatite crystals with forms very similar to the synthetic quench apatites. Acicular apatite crystals may prove to be of value as a criterion for the former existence of a liquid phase in rocks whose origin is debatable.", "doi": "10.1093/petrology/3.2.238", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1962", "series_number": "2", "volume": "3", "issue": "2", "pages": "238-243" }, { "id": "authors:6a4sc-c5c75", "collection": "authors", "collection_id": "6a4sc-c5c75", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-133601833", "type": "article", "title": "The System MgO-CO_2-H_2O at High Pressures and Temperatures", "author": [ { "family_name": "Walter", "given_name": "L. S.", "clpid": "Walter-L-S" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "The system MgO-CO_2-H_2O has been studied up to 1,400\u00b0 C and 4,000 bars pressure using the sealed-capsule quenching technique. No melting was observed. At 1,000 bars pressure magnesite dissociates at 780\u00b0 C, and brucite at 635\u00b0 C, to periclase and vapor. The univariant reaction MgCO_3\u00f7Mg(OH)_2 \u21cc MgO + V proceeds at 630\u00b0 C, at 1,000 bars and at 700\u00b0 C, at 4,000 bars. Solubility measurements show that, at 1,000 bars and temperatures up to 1,000\u00b0 C, less than 1.5 weight per cent MgO is dissolved in the vapor phase. Brucite is unstable in the presence of vapors containing more than a small amount of CO_2. The maximum percentage of CO_2 in a vapor that can coexist with brucite increases with decreasing pressure and with increasing temperature: 6 weight per cent CO_2 is the maximum at 630\u00b0 C, 1,000 bars, and 4 weight per cent at 700\u00b0 C, 4,000 bars. The phase relations in the isobaric TX prism for 1,000 bars pressure are described. The results illustrate two dissociation reactions, decarbonation and dehydration, occurring in the presence of a vapor phase containing two volatile components, H_2O and CO_2. Applications to metamorphism are briefly discussed.", "doi": "10.1093/petrology/3.1.49", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1962", "series_number": "1", "volume": "3", "issue": "1", "pages": "49-64" }, { "id": "authors:dh1c8-xv506", "collection": "authors", "collection_id": "dh1c8-xv506", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-101820809", "type": "article", "title": "Hydrothermal Melting of Shales", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "PT curves for the beginning of melting of five analysed shales in the presence of water vapour under pressure are 20\u00b0 C. to 40\u00b0 C. higher than the corresponding curve for granite. About 150\u00b0 C. above the beginning of melting, the shales are half-melted; this is higher than the liquidus curve of most granites. Refractive indices of the quenched liquids (1\u00b7495\u20131\u00b7505) indicate a granitic or granodioritic composition. Quartz, cordierite, mullite, hypersthene, anorthite, etc., are developed in the partially fused shales. Partial fusion of shales by a granitic magma, even if superheated, would produce a liquid no more basic than granodiorite. The chemical characteristics of the shales are compared with average igneous rocks, and there appears to be no possibility that fusion of shales could produce a basaltic magma. Complete fusion would produce a melt with composition distinct from normal igneous magmas.", "doi": "10.1017/S0016756800000078", "issn": "0016-7568", "publisher": "Cambridge University Press", "publication": "Geological Magazine", "publication_date": "1961-02", "series_number": "01", "volume": "98", "issue": "01", "pages": "56-66" }, { "id": "authors:2nt71-rgp51", "collection": "authors", "collection_id": "2nt71-rgp51", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160120-153736308", "type": "article", "title": "Experimental investigation of silicate systems containing two volatile components; Part 2, The effects of NH_3 and HF, in addition to H_2O on the melting temperatures of albite and granite", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "Addition of NH_3 to water-albite and water-granite mixtures at constant pressure raises the melting temperatures of albite and granite, whereas addition of HF to these mixtures causes marked lowering of melting temperatures. Results obtained at 2,750 bars pressure for charges containing 1:1 weight ratio of silicate to total volatiles are presented as perspective TX projections from within isobaric prisms onto the volatile faces of the prisms. In the presence of H_2O alone at 2,750 bars pressure, albite melts between 795\u00b0C. and 810\u00b0C., and granite begins to melt at 670\u00b0C.; in the presence of 8.2 weight percent N_ 3 solution, the melting interval of albite is 805\u00b0C. to 825\u00b0C., and granite begins to melt at 690\u00b0C.; in the presence of 8 weight percent HF solution, the melting interval of albite is 610\u00b0C. to 685\u00b0C., and granite begins to melt at 595\u00b0C. No chemical reaction was detected in systems containing NH_3, but considerable reaction occurs with HF. With increasing HF concentration in the system NaAlSi_3O_8-H_2O-HF, quartz becomes a stable phase and the system is no longer ternary. In the presence of HF solutions, albite crystals grow much larger than in the presence of H_2O alone.", "doi": "10.2475/ajs.259.2.128", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1961-02", "series_number": "2", "volume": "259", "issue": "2", "pages": "128-143" }, { "id": "authors:eh050-p1c38", "collection": "authors", "collection_id": "eh050-p1c38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-131343995", "type": "article", "title": "Fusion of Torridonian Sandstone by a Picrite Sill in Soay (Hebrides)", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Up to 92 per cent of the original minerals were fused during progressive metamorphism of Torridonian sediment by a picrite sill. The liquid precipitated microlites of tridymite, cordierite, hypersthene, and magnetite until that remaining quenched to a glass. Stages of fusion were determined by petrographic methods. After decomposition of sericite and reduction of haematite, liquid developed by fusion of feldspar and quartz. The composition of liquid in a fused xenolith at various stages was calculated from chemical and modal analyses. The chemical analysis indicates that fusion occurred in the presence of excess water-vapour. The melting and crystallization processes compare closely with the behaviour of similar compositions in the system NaAlSi_3O_8-KalSi_3O_8-SiO_2-H_2O. Liquidus temperatures corresponding to the calculated liquids provide temperature estimates. An upper pressure limit is given by the quartz-tridymite PT curve. It is estimated that the liquid crystallized between 1,025\u00b0C and 935\u00b0C at a water-vapour pressure of 430 kg/cm^2. Reaction between picrite and fused sediment indicates that maximum fusion occurred when crystallization of the picrite was almost completed. The estimated picrite intrusion temperature is at least 1,175\u00b0C.", "doi": "10.1093/petrology/2.1.1", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1961", "series_number": "1", "volume": "2", "issue": "1", "pages": "1-37" }, { "id": "authors:9fngh-dda65", "collection": "authors", "collection_id": "9fngh-dda65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-142432094", "type": "article", "title": "Experimental investigation of silicate systems containing two volatile components; part I, Geometrical considerations", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "A discussion of the geometric representation of a system which contains two volatiles and albite at constant pressure. The possible phase relations of the general case albite-H_2O-C (or any other volatile) is depicted on ternary isobaric (TX) prisms, following a detailed description of the PTX model of the system albite-H_2O. Isothermal, isobaric sections are also illustrated for the general case. The petrologic significance of these diagrams is illustrated by considering the intrusion of magma into limestone where the experimentally determined system albite-H_2O-CO_2 could be utilized to indicate a crystallization sequence.", "doi": "10.2475/ajs.258.7.498", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1960-09", "series_number": "7", "volume": "258", "issue": "7", "pages": "498-517" }, { "id": "authors:3y4j0-8vz27", "collection": "authors", "collection_id": "3y4j0-8vz27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-133931655", "type": "article", "title": "The System CaO-MgO-FeO-SiO_2 and its Bearing on the Origin of Ultrabasic and Basic Rocks", "author": [ { "family_name": "Wyllie", "given_name": "Peter J.", "clpid": "Wyllie-P-J" } ], "abstract": "Experimental data in the system CaO-MgO-FeO-SiO_2 suggest that there may be a plateau on the liquidus and solidus of the multicomponent system basalt-peridotite. If this is so, fusion of peridotite would produce only basaltie magmas over a wide temperature range; when the temperature reached a value such that the liquid crossed the threshold of the plateau, there would be a rapid increase in the amount of fusion for small temperature increases, with the formation of picritic magmas; basaltic magmas containing suspended forsteritic olivine crystals could dissolve them if the temperature rose slightly above that of the plateau threshold; a high proportion of a picritic magma would crystallize in a small temperature interval, with the precipitation of forsteritic olivine that was only slightly zoned. These possibilities are compared with current theories, and it is concluded that several petrological axioms may require critical re-examination. An experimental procedure is outlined to determine the shape of the liquidus and solidus in the basalt-peridotite system.", "doi": "10.1180/minmag.1960.032.249.05", "issn": "0026-461X", "publisher": "Mineralogical Society", "publication": "Mineralogical Magazine", "publication_date": "1960-06", "series_number": "249", "volume": "32", "issue": "249", "pages": "459-470" }, { "id": "authors:g2tmp-yvm11", "collection": "authors", "collection_id": "g2tmp-yvm11", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160107-160845708", "type": "article", "title": "The System CaO-CO_2-H_2O and the Origin of Carbonatites", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "The ternary isobaric (TX) prism for the system CaO\u2013CO_2\u2013H_2O was determined at 1,000 bars pressure between 600\u00b0 C and 1,320\u00b0 C. At this pressure, calcite melts incongruently at 1,310\u00b0 C, portlandite (Ca(OH)_2) melts congruently at 835\u00b0 C, a binary eutectic exists between calcite and portlandite at 685\u00b0 C, melting begins at 740\u00b0 C on the join calcite-water and the univariant (isobaric invariant) equilibria lime-calcite-portlandite-liquid and calcite-portlandite-liquid-vapour occur at 683\u00b0 C and 675\u00b0 C, respectively. The latter is the minimum liquidus temperature in the TX prism, and the composition of this liquid is 65CaO, 19CO_2, 16H_2O (in weight per cent). PT curves were determined for several univariant equilibria. In the binary system CaO-H_2O, four univariant curves meet at an invariant point, at 810\u00b0 C and 100 bars pressure. Portlandite dissociates only at pressures below this point. The minimum liquidus temperature in the ternary system varies between 685\u00b0 C and 640\u00b0 C in the pressure interval 27 bars to 4, 000 bars.\nLiquids in the system are regarded as simplified carbonatite magmas in which CaO represents the basic oxides, and CO_2 and H_2O the volatile constituents. The liquids have low viscosity as indicated by the rapid attainment of equilibrium and the observation that crystal settling takes place in 15-min runs. The existence of such liquids at moderate temperatures through a wide pressure range leaves little reason to doubt a magmatic origin for those carbonatites which appear to be intrusive. Differentiation could occur in multicomponent magmas by separation of the successive liquid fractions produced by crystallization of calcite, dolomite, and siderite. The determined phase relations do not favour an origin by gas transfer. The results also suggest that partial melting of limestones is likely at igneous contacts, and that impure limestones may be partially melted during high-grade regional metamorphism.", "doi": "10.1093/petrology/1.1.1", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "1960-02", "series_number": "1", "volume": "1", "issue": "1", "pages": "1-46" }, { "id": "authors:7y55j-kg932", "collection": "authors", "collection_id": "7y55j-kg932", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160119-141019338", "type": "article", "title": "Effect of carbon dioxide on the melting of granite and feldspars", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "Unlike water vapor and F, carbon dioxide under pressure has little or no effect on the rates of melting or crystallization of granite or alkali feldspars, and the melting temperatures are apparently unaffected except insofar as pressure per se raises the temperature of melting. The melting temperature of granite in the presence of a mixture of carbon dioxide and water vapor at a fixed total pressure is raised if the proportion of carbon dioxide in the vapor is increased, indicating that carbon dioxide is less soluble in granitic liquids than is water. Although the solubility of carbon dioxide in granitic liquids is too small to be determined directly by the techniques used, any appreciable solubility would produce a measurable lowering of the melting temperature. It is suggested that the solution of carbon dioxide in silicate liquids depends upon the availability of cations which are not structurally bound to the silicate network of the liquid and are therefore available for carbonate formation in the liquid.", "doi": "10.2475/ajs.257.9.648", "issn": "0002-9599", "publisher": "American Journal of Science", "publication": "American Journal of Science", "publication_date": "1959-11", "series_number": "9", "volume": "257", "issue": "9", "pages": "648-655" }, { "id": "authors:zqctq-cdx97", "collection": "authors", "collection_id": "zqctq-cdx97", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160107-160544362", "type": "article", "title": "Melting of Portlandite in the System CaO-H_2O", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "[No abstract]", "doi": "10.1111/j.1151-2916.1959.tb12974.x", "issn": "0002-7820", "publisher": "Wiley-Blackwell", "publication": "Journal of the American Ceramic Society", "publication_date": "1959-09", "series_number": "9", "volume": "42", "issue": "9", "pages": "448-449" }, { "id": "authors:wya37-98j36", "collection": "authors", "collection_id": "wya37-98j36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160121-135229197", "type": "article", "title": "Microscopic cordierite in fused Torridonian arkose", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "Progressive thermal metamorphism of Torridonian arkose by a picrite sill in Soay\n(Hebrides) has culminated in extensive fusion. Microlites of cordierite were precipitated\nfrom the liquid as colorless, six-sided prisms (maximum dimension 0.06 mm.) with abundant\nmagnetite inclusions. Refractive indices of the cordierite lie between 1.529 and 1.541,\nand (-) 2V is small. The cordierite is frequently twinned on (110), and rare cruciform\ntwins are also present. The latter have (021) or (101) as the probable twin plane. Only\n(110) and (130) have been reported previously as cordierite twin planes. The distortion\nindex, \u0394 (degree of distortion from hexagonal symmetry, measured by x-ray powder\ndiffraction), is 0.08. From independent evidence, the maximum P_(H2O) was 430 kg/cm^2,\nand the minimum temperature interval of cordierite crystallization was 1025\u00b0 C. to 935\u00b0 C.\nIf P_(H2O) were less than 430 kg/cm^2, the estimated crystallization temperatures would be\nhigher. A useful temperature scale may be established by: (1) correlation of the structural\nstate of cordierite with estimated temperature and pressure of water vapor in buchites,\nand (2) extension of hydrothermal studies on synthetic cordierites. Both approaches are\nrequired because the crystallization history of cordierite may affect its structural state.\nIt is probable that the crystallization histories of cordierites in most buchites followed\nsimilar patterns.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1959-09", "series_number": "9-10", "volume": "44", "issue": "9-10", "pages": "1039-1046" }, { "id": "authors:wy98t-qkj67", "collection": "authors", "collection_id": "wy98t-qkj67", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-105725983", "type": "article", "title": "Synthetic Carbonatite Magma", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "Judging from the literature during the past decade, there is a growing interest in problems related to the genesis of carbonatites and associated alkaline igneous rocks. The interest has undoubtedly been fostered by the discovery of large reserves of rare earths in these rocks. Many field geologists believe that carbonatites were emplaced as liquid magmas; but hitherto there has been no conclusive experimental evidence to support the existence of carbonatite liquids. In fact, from the available experimental evidence it seemed unlikely that such liquids could exist at the low temperatures indicated by field studies. We have recently obtained experimental evidence that simplified carbonatite magmas can exist at moderate temperatures through a wide range of pressures.", "doi": "10.1038/183770a0", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "1959-03-14", "series_number": "4663", "volume": "183", "issue": "4663", "pages": "770-770" }, { "id": "authors:gp90v-cy471", "collection": "authors", "collection_id": "gp90v-cy471", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160121-160029726", "type": "article", "title": "Melting of calcite in the presence of water", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" }, { "family_name": "Tuttle", "given_name": "O. F.", "clpid": "Tuttle-O-F" } ], "abstract": "In a recent note in this journal Paterson (1958) described the partial\nmelting of calcite in the presence of water and carbon dioxide at temperatures\n\"around 900\u00b0 C. to 1000\u00b0 C. at a total pressure of 50 bars.\nThe ratio of water vapor to carbon dioxide in the system was not known.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1959-03", "series_number": "3-4", "volume": "44", "issue": "3-4", "pages": "453-459" }, { "id": "authors:fg082-y7y44", "collection": "authors", "collection_id": "fg082-y7y44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160113-144642064", "type": "article", "title": "Discrepancies between optic axial angles of olivines measured over different bisectrices", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "More than 100 measurements of 2V were made on forsteritic olivines from two picrite\nsills in Soay, Scotland, using both double and single axis conoscopic methods. The mean of\ndouble axis measurements agrees closely with the mean of single axis measurements, but a\nsignificant difference exists between the means of double axis measurements made over\ndifferent bisectrices. Measurements of (-)2V\u03b1 are smaller than (-)2V\u03b3 by about 2.5\u00b0\nThe difference can be explained if the recorded angles are smaller than the true angles when\nhigh radial angles are measured on the universal stage, and calculations show that refraction\nand displacement of light within the central layers of the sphere could produce this\neffect. Optical measurements of minerals with 2V near 90\u00b0 may be unreliable unless corrections\nare made for the errors introduced by the high angles of tilt which are involved\nin the measurements.", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "1959-01", "series_number": "1-2", "volume": "44", "issue": "1-2", "pages": "49-64" }, { "id": "authors:169gx-b3b27", "collection": "authors", "collection_id": "169gx-b3b27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-100950588", "type": "article", "title": "Ice Recession in Dronning Louise Land, North-East Greenland", "author": [ { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "The existence of high rock thresholds beneath the glaciers of Dronning Louise Land is established and examples are described. It is concluded that decrease in the height of the Greenland Ice Cap and the consequent emergence of the rock thresholds is the dominant factor in the final stages of recession of the glaciers of Dronning Louise Land. It is tentatively suggested that this process has more than local significance, and may be an important factor in the recent recession of the glaciers in other parts of east Greenland.", "doi": "10.3198/1956JoG2-20-704-708", "issn": "0022-1430", "publisher": "International Glaciological Society", "publication": "Journal of Glaciology", "publication_date": "1956-10-01", "series_number": "20", "volume": "2", "issue": "20", "pages": "704-708" }, { "id": "authors:geqgm-3xh50", "collection": "authors", "collection_id": "geqgm-3xh50", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160112-095813671", "type": "article", "title": "A Scottish expedition to the Rink Glacier, West Greenland", "author": [ { "family_name": "Drever", "given_name": "H. I.", "clpid": "Drever-H-I" }, { "family_name": "Wyllie", "given_name": "P. J.", "clpid": "Wyllie-P-J" } ], "abstract": "One of the main objects of this expedition was a glaciological reconnaissance of the Rink and Umiamako glaciers in the northern part of the Umanak District of West Greenland. For three weeks in July and August, 1950, members of the expedition operated and explored in the area of these two glaciers which are comparatively inaccessible and, apart from their snouts, unknown. They had been photographed by the Danish Geodetic Aerial Survey during the previous summer, and we have pleasure in recording our debt to Professor N\u00f6rlund, Director of this Survey, for his very kind permission to publish two aerial photographs before completion of the new map. Before the war, the Umanak District was surveyed, on a scale of 1:250,000 by a Danish Ground Survey. The published maps were helpful to us, but were never intended to be accurate in detail. We have had to make a few modifications and additions based on our own direct observation in areas explored without the aid of aerial photographs which, through no fault but our own, we did not have with us in Greenland.", "doi": "10.1080/00369225108735468", "issn": "0036-9225", "publisher": "Royal Scottish Geographical Society", "publication": "Scottish Geographical Magazine", "publication_date": "1951-04", "series_number": "1", "volume": "67", "issue": "1", "pages": "1-9" } ]