[
{
"id": "authors:qvh30-y7x82",
"collection": "authors",
"collection_id": "qvh30-y7x82",
"cite_using_url": "https://authors.library.caltech.edu/records/qvh30-y7x82",
"type": "article",
"title": "Enhancement of magnetic properties of single grain flux-grown icosahedral AlCuFe quasicrystal by shock compression",
"author": [
{
"family_name": "Bardzi\u0144ski",
"given_name": "Piotr J\u00f3zef",
"orcid": "0000-0001-6171-6465",
"clpid": "Bardzi\u0144ski-Piotr-J\u00f3zef"
},
{
"family_name": "Kulesza",
"given_name": "Dagmara",
"orcid": "0000-0001-5932-7217"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Armstrong",
"given_name": "Stephen",
"orcid": "0000-0001-7325-4763",
"clpid": "Armstrong-Stephen"
},
{
"family_name": "Silevitch",
"given_name": "Daniel M.",
"orcid": "0000-0002-6347-3513",
"clpid": "Silevitch-D-M"
},
{
"family_name": "Rosenbaum",
"given_name": "T.F.",
"orcid": "0009-0008-6152-666X",
"clpid": "Rosenbaum-T-F"
},
{
"family_name": "Goraus",
"given_name": "Jerzy P.",
"orcid": "0000-0002-7711-727X"
},
{
"family_name": "Hunady",
"given_name": "Kyle",
"orcid": "0000-0001-8364-786X",
"clpid": "Hunady-Kyle"
},
{
"family_name": "Fultz",
"given_name": "B.",
"orcid": "0000-0002-6364-8782",
"clpid": "Fultz-B"
}
],
"abstract": "We report the effects of shock compression and release on the structural and magnetic properties of icosahedral Al-Cu-Fe quasicrystals grown via a self-flux method. A 3 kJ projectile impact modulates the quasicrystalline structure by introducing phason strain without inducing a phase transition, at pressures of 13.4 GPa (first shock) and 21.6 GPa (reflected shock). Magnetic moments and negative Curie–Weiss temperatures of this quasicrystal indicate dilute antiferromagnetic ordering. Shock compression enhanced the T = 10 K saturation magnetization, saturation field, and coercive field, suggesting reduced constraint of ideal icosahedral lattice geometry after shock compression. Both pre- and post-shock samples align the easy magnetization direction along the 5-fold axis at high fields, but the shock-compressed sample briefly shifts to a 2-fold axis at 8 T before returning to 5-fold at 9 T. A Fourier expansion retaining harmonics n = 1–6 is needed to correctly describe the angular dependence of the magnetic torque in the broad field range 20 mT–9 T. The emergence of the odd Fourier terms is a unique property of quasicrystalline magnetic anisotropy. The magnitudes of the even terms increased two-fold following shock compression.
",
"doi": "10.1016/j.actamat.2026.122177",
"issn": "1359-6454",
"publisher": "Elsevier",
"publication": "Acta Materialia",
"publication_date": "2026-06-01",
"volume": "311",
"pages": "122177"
},
{
"id": "authors:wd3j9-m0a40",
"collection": "authors",
"collection_id": "wd3j9-m0a40",
"cite_using_url": "https://authors.library.caltech.edu/records/wd3j9-m0a40",
"type": "article",
"title": "Structure and magnetic properties of Eu- and Nd-doped flux-grown icosahedral Al-Cu-Fe quasicrystals",
"author": [
{
"family_name": "Bardzi\u0144ski",
"given_name": "Piotr J\u00f3zef",
"orcid": "0000-0001-6171-6465",
"clpid": "Bardzi\u0144ski-Piotr-J\u00f3zef"
},
{
"family_name": "Kulesza",
"given_name": "Dagmara",
"orcid": "0000-0001-5932-7217"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Armstrong",
"given_name": "Stephen",
"orcid": "0000-0001-7325-4763",
"clpid": "Armstrong-Stephen"
},
{
"family_name": "Silevitch",
"given_name": "Daniel M.",
"orcid": "0000-0002-6347-3513",
"clpid": "Silevitch-D-M"
},
{
"family_name": "Rosenbaum",
"given_name": "T. F.",
"orcid": "0009-0008-6152-666X",
"clpid": "Rosenbaum-T-F"
}
],
"abstract": "We explore the possibility of modification of the magnetic properties of flux-grown icosahedral Al-Cu-Fe quasicrystals by individual and combined doping with Nd and Eu. Different dopants alter the Cu/Fe ratio of the icosahedral phase. In all three cases, the electron density is concentrated in even- and odd-parity vertices and even-parity body center of the hypercubic unit cell, which is consistent with the F-type icosahedral lattice of similar systems. Nd-doping is correlated with higher occupancy, probably with denser Cu or Fe atoms, of the even-parity body center of the six-dimensional unit cell. Doping with one lanthanide produces a semihard magnet, while the sample doped with both Nd and Eu shows soft magnetic properties. The highest observed remanence and saturation magnetization were achieved via Eu doping; Nd+Eu yields half that value, and Nd only is even lower. Negative Curie-Weiss temperatures indicate strong antiferromagnetic long-range ordering with effective magnetic moments much smaller than expected for the Fe content. Comparison of the effective anisotropy energy distribution versus angle and magnetic field revealed the easy magnetization direction along preferred high-symmetry axes. The appearance of both 3\u2062\ud835\udf03 and 5\u2062\ud835\udf03 Fourier coefficients in the description of the angular dependence of torque at any applied magnetic field indicates that the anisotropic magnetic response of the quasicrystal has different symmetry than what would be expected for cubic crystalline magnetic materials with linear or cubic anisotropy.
",
"doi": "10.1103/gxww-bj3f",
"issn": "2475-9953",
"publisher": "American Physical Society",
"publication": "Physical Review Materials",
"publication_date": "2025-12-29",
"series_number": "12",
"volume": "9",
"issue": "12",
"pages": "124415"
},
{
"id": "authors:j3hqh-a2838",
"collection": "authors",
"collection_id": "j3hqh-a2838",
"cite_using_url": "https://authors.library.caltech.edu/records/j3hqh-a2838",
"type": "article",
"title": "Raman Study of the Slobodka Ordinary Chondrite",
"author": [
{
"family_name": "Simopoulou",
"given_name": "M."
},
{
"family_name": "Baziotis",
"given_name": "I.",
"orcid": "0000-0003-0185-5847"
},
{
"family_name": "Ferri\u00e8re",
"given_name": "L.",
"orcid": "0000-0002-9082-6230"
},
{
"family_name": "Hu",
"given_name": "J.",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Sanchez\u2010Valle",
"given_name": "C."
},
{
"family_name": "Gamaletsos",
"given_name": "P.\u00a0N."
},
{
"family_name": "Palles",
"given_name": "D."
},
{
"family_name": "Berndt",
"given_name": "J."
},
{
"family_name": "Ma",
"given_name": "C.",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Klemme",
"given_name": "S."
},
{
"family_name": "Asimow",
"given_name": "P. D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "We carried out a detailed study of the texture, mineralogy, and spectroscopic properties of the Slobodka ordinary chondrite meteorite. Previous descriptions differ on the classification of this meteorite, so we re\u2010evaluated its petrologic type and shock stage. The observed texture and mineral chemistry are most consistent with the L4 chondrites. It records features of strong shock metamorphism mostly consistent with shock stage S4, including irregular and planar fractures, undulatory extinction, and mosaicism in olivine, pyroxene, and plagioclase. The distribution of shock damage was further evaluated at the mesoscale, revealing significant heterogeneity: regions of shock stage S4 are located near shock melt veins, a few selected areas indicate shock stage S3, and areas farther away from shock melt veins exhibit shock stage S2. The application of a range of in\u2010situ analytical techniques, including Raman spectroscopy and electron back\u2010scatter diffraction as well as microprobe, revealed the presence of five preserved high\u2010pressure phases within the investigated sample of Slobodka, namely albitic jadeite, tuite, majorite, wadsleyite, and xieite. Together, these findings demonstrate that Slobodka preserves textural and mineralogical characteristics indicative of the highly energetic impact that likely fragmented the parent body of the L\u2010chondrites.
",
"doi": "10.1002/jrs.6833",
"issn": "0377-0486",
"publisher": "Wiley",
"publication": "Journal of Raman Spectroscopy",
"publication_date": "2025-11",
"series_number": "11",
"volume": "56",
"issue": "11",
"pages": "1329-1344"
},
{
"id": "authors:xa6cv-dvq68",
"collection": "authors",
"collection_id": "xa6cv-dvq68",
"cite_using_url": "https://authors.library.caltech.edu/records/xa6cv-dvq68",
"type": "article",
"title": "Jonlarsenite, Al\u2084Cu\u2089, a new intermetallic phase in the Al\u2013Cu system discovered in a micrometeorite from Oslo, Norway",
"author": [
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306"
},
{
"family_name": "Kihle",
"given_name": "Jan B."
},
{
"family_name": "Cheng",
"given_name": "Guangming"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Yao",
"given_name": "Nan"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Guan",
"given_name": "Yunbin",
"orcid": "0000-0002-7636-3735",
"clpid": "Guan-Yunbin"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Steinhardt",
"given_name": "Paul J."
}
],
"abstract": "During project STARDUST, a systematic decade-long search for micrometeorites in Norway, over 5500 specimens were recovered. Among them, a micrometeorite labelled NMM/L2, collected from a rooftop in Oslo, Norway, revealed the presence of a previously unknown Al–Cu intermetallic alloy with Al4Cu9 stoichiometry. This new phase has been approved by the IMA Commission on New Minerals, Nomenclature and Classification as a new mineral species with the name jonlarsenite (IMA 2024-078a). The microspherule (∼200 µm in diameter) exhibits a scoriaceous morphology and mineralogical features consistent with micrometeorites, including the presence of olivine, oxides, Fe–Ni metal beads, and Ca-rich silicate glass. Jonlarsenite occurs as ∼2 µm grains intimately intergrown with Cu-bearing aluminum and is associated with magnesian olivine, spinel, taenite, and silicate glass. Its extraterrestrial origin is revealed by oxygen isotope compositions and chondritic bulk chemistry, similar to previously reported Al- and Cu-bearing meteoritic materials.
\nCharacterisation by electron probe microanalysis (EPMA), STEM energy-dispersive X-ray spectrometry (STEM-EDS), and HR-TEM indicated the mineral to be cubic, space group P-43m, with a≈8.70 Å and a calculated density of 6.979 g cm−3. The ideal chemical formula is Al4Cu9, with minor Fe substituting for both Al and Cu. Selected area electron diffraction (SAED) and high-angle annular dark-field scanning TEM (HAADF-STEM) imaging showed a perfect match with the known ordered structure of synthetic γ-Al4Cu9. Due to micrometre-scale grain size, physical properties could not be measured. Jonlarsenite expands the suite of known natural intermetallic Al–Cu(–Fe) phases and highlights the significance of micrometeorites as repositories of exotic materials formed under extreme astrophysical conditions.
",
"doi": "10.5194/ejm-37-783-2025",
"issn": "1617-4011",
"publisher": "European Geosciences Union",
"publication": "European Journal of Mineralogy",
"publication_date": "2025-10-21",
"series_number": "5",
"volume": "37",
"issue": "5",
"pages": "783-791"
},
{
"id": "authors:kja9p-bjf63",
"collection": "authors",
"collection_id": "kja9p-bjf63",
"cite_using_url": "https://authors.library.caltech.edu/records/kja9p-bjf63",
"type": "article",
"title": "New knowledge about shock events that affected the L-chondrite parent body from two heavily shocked L6 meteorite finds",
"author": [
{
"family_name": "Baziotis",
"given_name": "I.",
"orcid": "0000-0003-0185-5847"
},
{
"family_name": "Ferri\u00e8re",
"given_name": "L.",
"orcid": "0000-0002-9082-6230"
},
{
"family_name": "Ma",
"given_name": "C.",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Hu",
"given_name": "J.",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Palles",
"given_name": "D."
},
{
"family_name": "Asimow",
"given_name": "P. D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "We report new results from a study of shock\u2010related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high\u2010pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite. Based on the calibration of phase stability fields and majorite chemical variations from static experiments, we estimate peak shock conditions of 18–23 GPa and 1800–2100°C. However, both meteorites also contain minerals thought to record lower pressures, 14–18 GPa for wadsleyite, and possibly ~11.5 GPa for albitic jadeite. These are interpreted to have formed by cooling during partial release from the peak shock state. Although the presence of discrete shock melt veins demands spatial heterogeneity in the temperature field, we interpret the record of HP mineralogy in terms of temporal rather than spatial variation in pressure–temperature conditions during the shock and release event. Specifically, we infer that the cooling of shock melt veins to their liquidus occurred near peak pressure, whereas decompression began before the melt veins reached their solidus. NWA 4672 and NWA 12841 also display dense networks of shock melt veins, metal–sulfide segregations, and dark shock zones, implying a high density of pre\u2010existing weak zones and, thus, a high likelihood of fragmentation during atmospheric entry. A comparison with the Suizhou L6 chondrite, in which a total of 26 HP phases have been identified, suggests that differences in the identification and number of observed HP polymorphs mostly reflect differences in the completeness and spatial scale of analytical studies rather than a true difference in the intensity of shock processing. It remains quite likely that many shocked L chondrites host more HP phases than have been recognized so far. These new results indicate a need for further high\u2010resolution studies of L chondrites to distinguish between observational bias and true variations in the range of shock states they experienced.
",
"doi": "10.1111/maps.70054",
"issn": "1086-9379",
"publisher": "Wiley",
"publication": "Meteoritics & Planetary Science",
"publication_date": "2025-10-06",
"pages": "maps.70054"
},
{
"id": "authors:b3xs4-0wy42",
"collection": "authors",
"collection_id": "b3xs4-0wy42",
"cite_using_url": "https://authors.library.caltech.edu/records/b3xs4-0wy42",
"type": "article",
"title": "Metallic messengers from the cosmos: Rare (Al,Cu)-bearing meteorites from the Project Stardust collection",
"author": [
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306"
},
{
"family_name": "Larsen",
"given_name": "Jon"
},
{
"family_name": "Kihle",
"given_name": "Jan B."
},
{
"family_name": "Cheng",
"given_name": "Guangming"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Yao",
"given_name": "Nan"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Guan",
"given_name": "Yunbin",
"orcid": "0000-0002-7636-3735",
"clpid": "Guan-Yunbin"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Steinhardt",
"given_name": "Paul J."
}
],
"abstract": "We report the discovery of (Al,Cu)\u2010bearing metallic alloys in two micrometeorites found in the Project Stardust collection gathered from urban rooftop environments in Norway. Most of the alloys are the same as those found in the Khatyrka meteorite and other micrometeorites, though one has a composition that has not been reported previously. Oxygen isotope ratio measurements using secondary ion mass spectrometry show that the Project Stardust samples reported here, like all earlier examples of natural (Al,Cu)\u2010bearing alloys, contain material of chondritic affinity.
",
"doi": "10.1111/maps.14377",
"issn": "1086-9379",
"publisher": "Wiley",
"publication": "Meteoritics and Planetary Science",
"publication_date": "2025-07",
"series_number": "7",
"volume": "60",
"issue": "7",
"pages": "1609-1620"
},
{
"id": "authors:gc9dv-aqa59",
"collection": "authors",
"collection_id": "gc9dv-aqa59",
"cite_using_url": "https://authors.library.caltech.edu/records/gc9dv-aqa59",
"type": "article",
"title": "Magnetic response and hardness enhancement by spontaneous directional coarsening of Fe\u2082AlB\u2082 in quasicrystal-rich matrix",
"author": [
{
"family_name": "Bardzi\u0144ski",
"given_name": "Piotr J\u00f3zef",
"orcid": "0000-0001-6171-6465"
},
{
"family_name": "Weselski",
"given_name": "Marek",
"orcid": "0000-0001-7227-6186"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Fu",
"given_name": "Roger Rennan"
}
],
"abstract": "This study investigates the Al55Cu20Fe15B10 alloy system to understand the characteristics of the Fe2AlB2 (Cmmm) phase and its interactions with a quasicrystal-rich matrix. The alloy's composition was chosen for its boron content, which promotes the formation of well-defined Fe2AlB2 crystals. We examined how different heat treatments affect the alloy's microstructure, magnetic properties and hardness. Microstructural and Electron Backscatter Diffraction analyses revealed the stable icosahedral Al59Cu27Fe12B2 quasicrystalline phase and a metastable Al70Fe20Cu10 approximant that is isostructural with C2/m Fe4Al13. Additionally, the alloy contained Al-Cu phases known from meteorites, such as AlCu stolperite and Al2Cu khatyrkite. Heat treatments at 706\u2218C and 828\u2218C yielded favorable microstructure for ballistic armor, characterized by Fe2AlB2 lamellae embedded within the quasicrystalline matrix, reinforced by AlB2 precipitation on the grain boundaries. Vickers hardness improvements were attributed to Hall-Petch strengthening and grain orientation effects. Notably, annealing at 943\u2218C nearly tripled the magnetic entropy change. Quantum Diamond Microscopy confirmed that Fe2AlB2 significantly contributed to magnetization. The improvement of magnetic properties was found to be due to preferential orientation of Fe2AlB2 grains along the [010] zone axis, as a consequence of directional coarsening induced by annealing. The enhanced magnetocaloric properties observed at 943\u2218C are primarily due to intrinsic changes in the Fe2AlB2 phase rather than strain relaxation or phase contributions from the quasicrystalline matrix.",
"doi": "10.1016/j.jallcom.2024.177791",
"issn": "0925-8388",
"publisher": "Elsevier",
"publication": "Journal of Alloys and Compounds",
"publication_date": "2025-01-05",
"volume": "1010",
"pages": "177791"
},
{
"id": "authors:8e2xr-0py82",
"collection": "authors",
"collection_id": "8e2xr-0py82",
"cite_using_url": "https://authors.library.caltech.edu/records/8e2xr-0py82",
"type": "article",
"title": "Quasicrystal synthesis by shock compression",
"author": [
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Steinhardt",
"given_name": "Paul J.",
"orcid": "0000-0003-3488-1603"
},
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306"
}
],
"abstract": "Quasicrystals are of interest because of their unique nonperiodic structures and physical properties. Motivated by naturally occurring icosahedral AlCuFe- and decagonal AlNiFe-phases hosted in a shocked meteorite, different laboratories have undertaken a series of shock recovery experiments to understand their formation mechanism. Shock experiments generate a complex series of processes and conditions, including a near-instantaneous excursion to high pressure and high temperature, large shear stresses, local melting, rapid decompression, fast quenching and post-shock annealing. This highly dynamic scenario offers a very useful but imperfect tool for exploring the stability of novel alloys, such as quasicrystals. So far, all the shock-synthesized quasicrystals differ considerably in composition from any thermodynamically stable or metastable quasicrystals synthesized by metallurgical techniques at low pressure, leaving plenty of questions to be answered about their formation conditions and their nucleation and growth mechanisms occurring during shock experiments. In this Perspective, we summarize the previous studies of shock-synthesized quasicrystals and discuss the advantages and difficulties caused by the experimental complexity. We also propose a few directions for future experiments to better control the shock conditions and understand the properties of quasicrystals.",
"doi": "10.1038/s42004-024-01319-8",
"issn": "2399-3669",
"publisher": "Nature Publishing Group",
"publication": "Communications Chemistry",
"publication_date": "2024-10-10",
"series_number": "1",
"volume": "7",
"issue": "1",
"pages": "232"
},
{
"id": "authors:te72b-5q450",
"collection": "authors",
"collection_id": "te72b-5q450",
"cite_using_url": "https://authors.library.caltech.edu/records/te72b-5q450",
"type": "article",
"title": "Al-Cu-Fe alloys in the solar system: Going inside a Khatyrka-like micrometeorite (KT01) from the Nubian Desert, Sudan",
"author": [
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Suttle",
"given_name": "Martin D.",
"orcid": "0000-0001-7165-2215",
"clpid": "Suttle-Martin-D"
},
{
"family_name": "Guan",
"given_name": "Yunbin",
"clpid": "Guan-Yunbin"
},
{
"family_name": "Sharp",
"given_name": "Thomas G.",
"clpid": "Sharp-Thomas-G"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Steinhardt",
"given_name": "Paul J.",
"orcid": "0000-0003-3488-1603",
"clpid": "Steinhardt-Paul-J"
},
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306",
"clpid": "Bindi-Luca"
}
],
"abstract": "\n
\n
A recently described micrometeorite from the Nubian desert (Sudan) contains an exotic Al-Cu-Fe assemblage closely resembling that observed in the Khatyrka chondrite (Suttle et al., 2019; Science Reports 9:12426). We here extend previous investigations of the geochemical, mineralogical, and petrographic characteristics of the Sudan spherule by measuring oxygen isotope ratios in the silicate components and by nano-scale transmission electron microscopy study of a focused ion beam foil that samples the contact between Al-Cu alloys and silicates. O-isotope work indicates an affinity to either OC or CR chondrites, while ruling out a CO or CM precursor. When combined with petrographic evidence we conclude that a CR chondrite parentage is the most likely origin for this micrometeorite. SEM and TEM studies reveal that the Al-Cu alloys mainly consist of Al metal, stolperite (CuAl), and khatyrkite (CuAl2) together with inclusions in stolperite of a new nanometric, still unknown Al-Cu phase with a likely nominal Cu3Al2 stoichiometry. At the interface between the alloy assemblage and the surrounding silicate, there is a thin layer (200 nm) of almost pure MgAl2O4 spinel along with well-defined and almost perfectly spherical metallic droplets, predominantly iron in composition. The study yields additional evidence that Al-Cu alloys, the likely precursors to quasicrystals in Khatyrka, occur naturally. Moreover, it implies the existence of multiple pathways leading to the association in reduced form of these two elements, one highly lithophile and the other strongly chalcophile.
\n
\n
",
"doi": "10.1111/maps.14089",
"issn": "1086-9379",
"publication": "Meteoritics and Planetary Science",
"publication_date": "2023-11-08",
"series_number": "11",
"volume": "58",
"issue": "11",
"pages": "1642-1653"
},
{
"id": "authors:jc95e-ezk64",
"collection": "authors",
"collection_id": "jc95e-ezk64",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230519-1751000.22",
"type": "article",
"title": "Shock-recovered maskelynite indicates low-pressure ejection of shergottites from Mars",
"author": [
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Liu",
"given_name": "Yang",
"orcid": "0000-0003-0308-0942",
"clpid": "Liu-Yang"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
}
],
"abstract": "Diaplectic feldspathic glass, commonly known as maskelynite, is a widely used impact indicator, notably for shergottites, whose shock conditions are keys to their geochemistry and launch mechanism. However, classic reverberating shock recovery experiments show maskelynitization at higher shock pressures (>30 gigapascals) than the stability field of the high-pressure minerals found in many shergottites (15 to 25 gigapascals). Most likely, differences between experimental loading paths and those appropriate for martian impacts have created this ambiguity in shergottite shock histories. Shock reverberation yields lower temperature and deviatoric stress than single-shock planetary impacts at equivalent pressure. We report the Hugoniot equation of state of a martian analog basalt and single-shock recovery experiments, indicating partial-to-complete maskelynitization at 17 to 22 gigapascals, consistent with the high-pressure minerals in maskelynitized shergottites. This pressure explains the presence of intact magmatic accessory minerals, used for geochronology in shergottites, and offers a new pressure-time profile for modeling shergottite launch, likely requiring greater origin depth.",
"doi": "10.1126/sciadv.adf2906",
"pmcid": "PMC10156110",
"issn": "2375-2548",
"publisher": "American Association for the Advancement of Science",
"publication": "Science Advances",
"publication_date": "2023-05-03",
"series_number": "18",
"volume": "9",
"issue": "18",
"pages": "Art. No. adf2906"
},
{
"id": "authors:1nd3e-8fs95",
"collection": "authors",
"collection_id": "1nd3e-8fs95",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221128-494241100.28",
"type": "article",
"title": "Investigation of the shocked Vi\u00f1ales ordinary chondrite (L6) meteorite fall \u2013 Implications for shock classification, fragmentation, and collision dynamics",
"author": [
{
"family_name": "Baziotis",
"given_name": "I. P.",
"orcid": "0000-0003-0185-5847",
"clpid": "Baziotis-Ioannis-P"
},
{
"family_name": "Xydous",
"given_name": "S.",
"clpid": "Xydous-Stamatios"
},
{
"family_name": "Papoutsa",
"given_name": "A.",
"clpid": "Papoutsa-Angeliki"
},
{
"family_name": "Hu",
"given_name": "J.",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Ma",
"given_name": "C.",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Ferri\u00e8re",
"given_name": "L.",
"orcid": "0000-0002-9082-6230",
"clpid": "Ferri\u00e8re-Ludovic"
},
{
"family_name": "Klemme",
"given_name": "S.",
"orcid": "0000-0001-7859-9779",
"clpid": "Klemme-Stephan"
},
{
"family_name": "Berndt",
"given_name": "J",
"orcid": "0000-0002-6766-3066",
"clpid": "Berndt-Jasper"
},
{
"family_name": "Asimow",
"given_name": "P. D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "The effects of collisions on the evolution of asteroids, ranging from local fracturing to brecciation or even to catastrophic disruption, depend primarily on the encounter velocities. Here we present a refined view of the mineralogy and texture of the recent fall Vi\u00f1ales, an L6 ordinary chondrite meteorite. It preserves features that require at least one energetic impact, including numerous shock melt veins of variable thickness. We report the identification of two high-pressure phases, majorite and albitic jadeite, limited to just one of these shock melt veins. Vi\u00f1ales is a moderately shocked sample, shock stage S4, that experienced a complex and spatially variable pressure-temperature-time history with a low (but non-zero) probability of preservation of high-pressure phases.",
"doi": "10.1016/j.icarus.2022.115326",
"issn": "0019-1035",
"publisher": "Elsevier",
"publication": "Icarus",
"publication_date": "2023-01-15",
"volume": "390",
"pages": "Art. No. 115326"
},
{
"id": "authors:5qbt9-yk892",
"collection": "authors",
"collection_id": "5qbt9-yk892",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230717-55375900.13",
"type": "article",
"title": "Electrical discharge triggers quasicrystal formation in an eolian dune",
"author": [
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306",
"clpid": "Bindi-Luca"
},
{
"family_name": "Pasek",
"given_name": "Matthew A.",
"orcid": "0000-0003-1280-9555",
"clpid": "Pasek-Matthew-A"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Cheng",
"given_name": "Guangming",
"orcid": "0000-0001-5852-1341",
"clpid": "Cheng-Guangming"
},
{
"family_name": "Yao",
"given_name": "Nan",
"orcid": "0000-0002-4081-1495",
"clpid": "Yao-Nan"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Steinhardt",
"given_name": "Paul J.",
"orcid": "0000-0003-3488-1603",
"clpid": "Steinhardt-Paul-J"
}
],
"abstract": "We report the discovery of a dodecagonal quasicrystal Mn_(72.3)Si_(15.6)Cr_(9.7)Al_(1.8)Ni_(0.6)\u2014composed of a periodic stacking of atomic planes with quasiperiodic translational order and 12-fold symmetry along the two directions perpendicular to the planes\u2014accidentally formed by an electrical discharge event in an eolian dune in the Sand Hills near Hyannis, Nebraska, United States. The quasicrystal, coexisting with a cubic crystalline phase with composition Mn_(68.9)Si_(19.9)Ni_(7.6)Cr_(2.2)Al_(1.4), was found in a fulgurite consisting predominantly of fused and melted sand along with traces of melted conductor metal from a nearby downed power line. The fulgurite may have been created by a lightning strike that combined sand with material from downed power line or from electrical discharges from the downed power line alone. Extreme temperatures of at least 1,710 \u00b0C were reached, as indicated by the presence of SiO\u2082 glass in the sample. The dodecagonal quasicrystal is an example of a quasicrystal of any kind formed by electrical discharge, suggesting other places to search for quasicrystals on Earth or in space and for synthesizing them in the laboratory.",
"doi": "10.1073/pnas.2215484119",
"pmcid": "PMC9910441",
"issn": "0027-8424",
"publisher": "National Academy of Sciences",
"publication": "Proceedings of the National Academy of Sciences of the United States of America",
"publication_date": "2023-01-03",
"series_number": "1",
"volume": "120",
"issue": "1",
"pages": "Art. No. e2215484119"
},
{
"id": "authors:dcbra-6ja81",
"collection": "authors",
"collection_id": "dcbra-6ja81",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20221013-48863000.11",
"type": "article",
"title": "Jadeite and related species in shocked meteorites: Limitations on inference of shock conditions",
"author": [
{
"family_name": "Baziotis",
"given_name": "Ioannis",
"orcid": "0000-0003-0185-5847",
"clpid": "Baziotis-Ioannis-P"
},
{
"family_name": "Xydous",
"given_name": "Stamatios",
"clpid": "Xydous-Stamatios"
},
{
"family_name": "Papoutsa",
"given_name": "Angeliki",
"clpid": "Papoutsa-Angeliki"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Klemme",
"given_name": "Stephan",
"clpid": "Klemme-Stephan"
},
{
"family_name": "Berndt",
"given_name": "Jasper",
"clpid": "Berndt-Jasper"
},
{
"family_name": "Ferri\u00e8re",
"given_name": "Ludovic",
"orcid": "0000-0002-9082-6230",
"clpid": "Ferri\u00e8re-Ludovic"
},
{
"family_name": "Caracas",
"given_name": "Razvan",
"orcid": "0000-0003-4586-776X",
"clpid": "Caracas-Razvan"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "Jadeite is frequently reported in shocked meteorites, displaying a variety of textures and grain sizes that suggest formation by either solid-state transformation or by crystallization from a melt. Some-times, jadeite has been identified solely on the basis of Raman spectra. Here we argue that additional characterization is needed to confidently identify jadeite and distinguish it from related species. Based on chemical and spectral analysis of three new occurrences, complemented by first-principles calculations, we show that related pyroxenes in the chemical space (Na)\u1d39\u00b2(Al)\u1d39\u00b9(Si\u2082)\u1d40O\u2086\u2013(Ca)\u1d39\u00b2(Al)\u1d39\u00b9(AlSi)\u1d40O\u2086\u2013(\u2610)\u1d39\u00b2(Si)\u1d39\u00b9(Si\u2082)\u1d40O\u2086 with up to 2.25 atoms Si per formula unit have spectral features similar to jadeite. However, their distinct stability fields (if any) and synthesis pathways, considered together with textural constraints, have different implications for precursor phases and estimates of impactor size, encounter velocity, and crater diameter. A reassessment of reported jadeite occurrences casts a new light on many previous conclusions about the shock histories preserved in particular meteorites.",
"doi": "10.2138/am-2022-8220",
"issn": "0003-004X",
"publisher": "Mineralogical Society of America",
"publication": "American Mineralogist",
"publication_date": "2022-10",
"series_number": "10",
"volume": "107",
"issue": "10",
"pages": "1868-1877"
},
{
"id": "authors:wmpmv-h3r68",
"collection": "authors",
"collection_id": "wmpmv-h3r68",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220413-973965500",
"type": "article",
"title": "Unique evidence of fluid alteration in the Kakowa (L6) ordinary chondrite",
"author": [
{
"family_name": "Baziotis",
"given_name": "I. P.",
"orcid": "0000-0003-0185-5847",
"clpid": "Baziotis-Ioannis-P"
},
{
"family_name": "Ma",
"given_name": "C.",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Guan",
"given_name": "Y.",
"orcid": "0000-0002-7636-3735",
"clpid": "Guan-Yunbin"
},
{
"family_name": "Ferri\u00e8re",
"given_name": "L.",
"orcid": "0000-0002-9082-6230",
"clpid": "Ferri\u00e8re-Ludovic"
},
{
"family_name": "Xydous",
"given_name": "S.",
"clpid": "Xydous-S"
},
{
"family_name": "Hu",
"given_name": "J.",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Kipp",
"given_name": "M. A.",
"orcid": "0000-0003-1844-3670",
"clpid": "Kipp-Michael-A"
},
{
"family_name": "Tissot",
"given_name": "F. L. H.",
"orcid": "0000-0001-6622-2907",
"clpid": "Tissot-F-L-H"
},
{
"family_name": "Asimow",
"given_name": "P. D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "Meteorites preserve evidence of processes on their parent bodies, including alteration, metamorphism, and shock events. Here we show that the Kakowa (L6) ordinary chondrite (OC) preserves both shock-melt veins and pockets of detrital grains from a brecciated and altered object, including corundum, albite, silica, fayalite, forsterite, and margarite in a Pb- and Fe-rich matrix. Preservation of the observed mineralogy and texture requires a sequence of at least two impacts: first, a high-velocity collision formed the shock melt veins containing the high-pressure minerals ringwoodite, wadsleyite, majorite, and albitic jadeite; later, a low-velocity impact formed fractures and filled them with the detrital material. Oxygen and Pb isotope ratios suggest an OC origin for these detrital minerals. Although fluid alteration is common in carbonaceous chondrites, the discovery of margarite with an OC oxygen isotopic signature is novel. Kakowa extends both the impact and alteration history of L6 ordinary chondrites in general.",
"doi": "10.1038/s41598-022-09465-6",
"pmcid": "PMC9005539",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2022-04-12",
"volume": "12",
"pages": "Art. No. 5520"
},
{
"id": "authors:9fzna-tfg57",
"collection": "authors",
"collection_id": "9fzna-tfg57",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20220121-870668000",
"type": "article",
"title": "Formation, preservation and extinction of high-pressure minerals in meteorites: temperature effects in shock metamorphism and shock classification",
"author": [
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Sharp",
"given_name": "Thomas G.",
"orcid": "0000-0003-2287-9370",
"clpid": "Sharp-Thomas-G"
}
],
"abstract": "The goal of classifying shock metamorphic features in meteorites is to estimate the corresponding shock pressure conditions. However, the temperature variability of shock metamorphism is equally important and can result in a diverse and heterogeneous set of shock features in samples with a common overall shock pressure. In particular, high-pressure (HP) minerals, which were previously used as a solid indicator of high shock pressure in meteorites, require complex pressure\u2013temperature\u2013time (P\u2013T\u2013t) histories to form and survive. First, parts of the sample must be heated to melting temperatures, at high pressure, to enable rapid formation of HP minerals before pressure release. Second, the HP minerals must be rapidly cooled to below a critical temperature, before the pressure returns to ambient conditions, to avoid retrograde transformation to their low-pressure polymorphs. These two constraints require the sample to contain large temperature heterogeneities, e.g. melt veins in a cooler groundmass, during shock. In this study, we calculated shock temperatures and possible P\u2013T paths of chondritic and differentiated mafic\u2013ultramafic rocks for various shock pressures. These P\u2013T conditions and paths, combined with observations from shocked meteorites, are used to constrain shock conditions and P\u2013T\u2013t histories of HP-mineral bearing samples. The need for rapid thermal quench of HP phases requires a relatively low bulk-shock temperature and therefore moderate shock pressures below ~\u200930\u00a0GPa, which matches the stabilities of these HP minerals. The low-temperature moderate-pressure host rock generally shows moderate shock-deformation features consistent with S4 and, less commonly, S5 shock stages. Shock pressures in excess of 50\u00a0GPa in meteorites result in melt breccias with high overall post-shock temperatures that anneal out HP-mineral signatures. The presence of ringwoodite, which is commonly considered an indicator of the S6 shock stage, is inconsistent with pressures in excess of 30\u00a0GPa and does not represent shock conditions different from S4 shock conditions. Indeed, ringwoodite and coexisting HP minerals should be considered as robust evidence for moderate shock pressures (S4) rather than extreme shock (S6) near whole-rock melting.",
"doi": "10.1186/s40645-021-00463-2",
"pmcid": "PMC8732827",
"issn": "2197-4284",
"publisher": "Springer",
"publication": "Progress in Earth and Planetary Science",
"publication_date": "2022-01-05",
"volume": "9",
"pages": "Art. No. 6"
},
{
"id": "authors:wv4sy-n4r50",
"collection": "authors",
"collection_id": "wv4sy-n4r50",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200511-101653760",
"type": "article",
"title": "First synthesis of a unique icosahedral phase from the Khatyrka meteorite by shock-recovery experiment",
"author": [
{
"family_name": "Hu",
"given_name": "Jinping",
"clpid": "Hu-Jinping"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306",
"clpid": "Bindi-Luca"
}
],
"abstract": "Icosahedral quasicrystals (i-phases) in the Al\u2013Cu\u2013Fe system are of great interest because of their perfect quasicrystalline structure and natural occurrences in the Khatyrka meteorite. The natural quasicrystal of composition Al\u2086\u2082Cu\u2083\u2081Fe\u2087, referred to as i-phase II, is unique because it deviates significantly from the stability field of i-phase and has not been synthesized in a laboratory setting to date. Synthetic i-phases formed in shock-recovery experiments present a novel strategy for exploring the stability of new quasicrystal compositions and prove the impact origin of natural quasicrystals. In this study, an Al\u2013Cu\u2013W graded density impactor (GDI, originally manufactured as a ramp-generating impactor but here used as a target) disk was shocked to sample a full range of Al/Cu starting ratios in an Fe-bearing 304 stainless-steel target chamber. In a strongly deformed region of the recovered sample, reactions between the GDI and the steel produced an assemblage of co-existing Al_(61.5)Cu_(30.3)Fe_(6.8)Cr_(1.4) i-phase II + stolperite (\u03b2, AlCu) + khatyrkite (\u03b8, Al\u2082Cu), an exact match to the natural i-phase II assemblage in the meteorite. In a second experiment, the continuous interface between the GDI and steel formed another more Fe-rich quinary i-phase (Al_(68.6)Fe_(14.5)Cu_(11.2)Cr\u2084Ni_(1.8)), together with stolperite and hollisterite (\u03bb, Al\u2081\u2083Fe\u2084), which is the expected assemblage at phase equilibrium. This study is the first laboratory reproduction of i-phase II with its natural assemblage. It suggests that the field of thermodynamically stable icosahedrite (Al\u2086\u2083Cu\u2082\u2084Fe\u2081\u2083) could separate into two disconnected fields under shock pressure above 20 GPa, leading to the co-existence of Fe-rich and Fe-poor i-phases like the case in Khatyrka. In light of this, shock-recovery experiments do indeed offer an efficient method of constraining the impact conditions recorded by quasicrystal-bearing meteorite, and exploring formation conditions and mechanisms leading to quasicrystals.",
"doi": "10.1107/s2052252520002729",
"pmcid": "PMC7201281",
"issn": "2052-2525",
"publisher": "International Union of Crystallography",
"publication": "International Union of Crystallography Journal",
"publication_date": "2020-05",
"series_number": "3",
"volume": "7",
"issue": "3",
"pages": "434-444"
},
{
"id": "authors:fbv11-xq071",
"collection": "authors",
"collection_id": "fbv11-xq071",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190709-100325481",
"type": "article",
"title": "Shock Veins in Meteorites: What They Tell Us About Shock Conditions",
"author": [
{
"family_name": "Sharp",
"given_name": "T. G.",
"clpid": "Sharp-T-G"
},
{
"family_name": "Hu",
"given_name": "J.",
"clpid": "Hu-Jinping"
}
],
"abstract": "The goal of classifying the shock metamorphic features in meteorites is to estimate the corresponding\nshock pressure conditions [1]. However, the temperature variability of shock metamorphism is equally\nimportant and can result in diverse shock features in samples with equilibrated pressures. Shock-melt veins and melt\npockets correspond to the highest temperatures in shock meteorites and they are the location of high-pressure (HP)\nminerals [2]. The usefulness of shock veins for interpreting shock conditions is debated. Stoeffler et al [3] suggest\nthat shock veins do not provide useful estimates of shock pressure because they represent large deviations from average\nshock effects. However, these features provide an important mineralogical and chemical record of shock history\n[4]. Fritz et al. [5] claim that shock veins and HP minerals only record peak shock pressure in the isobaric zone\nfor low-velocity (~ 2km/s) impacts, such as that recorded in L chondrites. Although other shocked materials may not\nsample the isobaric zone, their crystallization history is still useful for understanding the shock history. Here we\ncalculate shock-temperatures and quench paths to semi-quantitatively evaluate the relationship between shock-melt\ncrystallization and shock pressure.",
"doi": "10.1111/maps.13346",
"issn": "1086-9379",
"publisher": "Meteoritical Society",
"publication": "Meteoritics and Planetary Science",
"publication_date": "2019-08",
"series_number": "S2",
"volume": "54",
"issue": "S2",
"pages": "6463"
},
{
"id": "authors:jyhpf-0wf64",
"collection": "authors",
"collection_id": "jyhpf-0wf64",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20181126-100419186",
"type": "article",
"title": "Shock conditions recorded in NWA 8159 martian augite basalt with implications for the impact cratering history on Mars",
"author": [
{
"family_name": "Sharp",
"given_name": "Thomas G.",
"clpid": "Sharp-T-G"
},
{
"family_name": "Walton",
"given_name": "Erin L.",
"orcid": "0000-0003-1301-5300",
"clpid": "Walton-E-L"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"clpid": "Hu-Jinping"
},
{
"family_name": "Agee",
"given_name": "Carl",
"clpid": "Agee-C-B"
}
],
"abstract": "NWA 8159 is an augite-rich martian basalt, formed by cooling of a relatively evolved, Ca-rich, Ti-poor and LREE-depleted lava, under relatively oxidizing conditions, during the early Amazonian. In addition to its distinct igneous petrogenesis and high fO_2, NWA 8159 is also set apart from most martian shergottites with respect to the low degree of shock metamorphism required to preserve crystalline igneous plagioclase (An_(50\u201365)). In this study, mineral transformations within and adjacent to shock veins in NWA 8159 were investigated using scanning electron microscopy, Raman spectroscopy and transmission electron microscopy to better constrain the unusal shock history of this meteorite. The transformation of olivine to ahrensite (Fe-ringwoodite) along shock vein margins, and tissintite and coesiteformed from igneous mineral (labradorite and silica) grains entrained as clasts within shock veins has been documented in this study. We report on a previously unidentified mineral assemblage of Ca-Na-majoritic garnet, sodic-clinopyroxene and stishovite crystallized from shock melt. This mineral assemblage indicates a crystallization pressure of approximately 16\u202fGPa, which is within the range of previous shock pressure estimates for this meteorite (15\u201323\u202fGPa). The presence of a majoritic garnet-bearing assemblage throughout veins up to 0.6\u202fmm wide indicates that the sample remained at high-pressure throughout the melt vein quench. Based on thermal models, the sample must have remained at high pressure for \u223c100\u202fms. This shock duration is an order of magnitude longer than those experienced by more highly shocked shergottites such as Tissint or Zagami (>30\u202fGPa; 10\u201320\u202fms) and would seem to imply a relatively large impact event. Recent numerical models demonstrate that a range of shock pressures and durations are realized by rocks within the ejected spall zone of a hypervelocity impact. The shock conditions experienced by NWA 8159 therefore do not require an impact event distinct from other shergottites. Rather, our findings suggest that this meteorite originated from near the martian surface at the edge of the impact site. The shock history of NWA 8159 provides a picture of Mars consistent with that derived from remote observation; that of a random cratering process that samples a geologically long-lived and complex planet.",
"doi": "10.1016/j.gca.2018.11.014",
"issn": "0016-7037",
"publisher": "Elsevier",
"publication": "Geochimica et Cosmochimica Acta",
"publication_date": "2019-02-01",
"volume": "246",
"pages": "197-212"
},
{
"id": "authors:gvkbv-9rk67",
"collection": "authors",
"collection_id": "gvkbv-9rk67",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180629-093135665",
"type": "article",
"title": "High pressure minerals in the Ch\u00e2teau-Renard (L6) ordinary chondrite: implications for collisions on its parent body",
"author": [
{
"family_name": "Baziotis",
"given_name": "Ioannis",
"orcid": "0000-0003-0185-5847",
"clpid": "Baziotis-Ioannis-P"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Ferri\u00e8re",
"given_name": "Ludovic",
"orcid": "0000-0002-9082-6230",
"clpid": "Ferri\u00e8re-Ludovic"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "\u010cernok",
"given_name": "Ana",
"orcid": "0000-0002-9884-6535",
"clpid": "\u010cernok-Ana"
},
{
"family_name": "Anand",
"given_name": "Mahesh",
"orcid": "0000-0003-4026-4476",
"clpid": "Anand-Mahesh"
},
{
"family_name": "Topa",
"given_name": "Dan",
"clpid": "Topa-Dan"
}
],
"abstract": "We report the first discoveries of high-pressure minerals in the historical L6 chondrite fall Ch\u00e2teau-Renard, based on co-located Raman spectroscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy and electron backscatter diffraction, electron microprobe analysis, and transmission electron microscopy (TEM) with selected-area electron diffraction. A single polished section contains a network of melt veins from ~40 to ~200\u2009\u03bcm wide, with no cross-cutting features requiring multiple vein generations. We find high-pressure minerals in veins greater than ~50\u2009\u03bcm wide, including assemblages of ringwoodite\u2009+\u2009wadsleyite, ringwoodite\u2009+\u2009wadsleyite\u2009+\u2009majorite-pyrope_(ss), and ahrensite\u2009+\u2009wadsleyite. In association with ahrensite\u2009+\u2009wadsleyite at both SEM and TEM scale, we find a sodic pyroxene whose Raman spectrum is indistinguishable from that of jadeite but whose composition and structure are those of omphacite. We discuss constraints on the impact record of this meteorite and the L-chondrites in general.",
"doi": "10.1038/s41598-018-28191-6",
"pmcid": "PMC6026127",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2018-06-29",
"volume": "8",
"pages": "Art. No. 9851"
},
{
"id": "authors:176j9-6tx58",
"collection": "authors",
"collection_id": "176j9-6tx58",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171115-105645635",
"type": "article",
"title": "Shock Synthesis of Five-component Icosahedral Quasicrystals",
"author": [
{
"family_name": "Oppenheim",
"given_name": "Julius",
"orcid": "0000-0002-5988-0677",
"clpid": "Oppenheim-Julius-J"
},
{
"family_name": "Ma",
"given_name": "Chi",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Hu",
"given_name": "Jinping",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Bindi",
"given_name": "Luca",
"orcid": "0000-0003-1168-7306",
"clpid": "Bindi-Luca"
},
{
"family_name": "Steinhardt",
"given_name": "Paul J.",
"clpid": "Steinhardt-Paul-J"
},
{
"family_name": "Asimow",
"given_name": "Paul D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "Five-component icosahedral quasicrystals with compositions in the range Al_(68\u201373)Fe_(11\u201316)Cu_(10\u201312)Cr_(1\u20134)Ni_(1\u20132) were recently recovered after shocking metallic CuAl_5 and (Mg_(0.75)Fe_(0.25))_2SiO_4 olivine in a stainless steel 304 chamber, intended to replicate a natural shock that affected the Khatyrka meteorite. The iron in those quasicrystals might have originated either from reduction of Fe^(2+) in olivine or from the stainless steel chamber. In this study, we clarify the shock synthesis mechanism of icosahedral quasicrystals through two new shock recovery experiments. When CuAl_5 and Fe^(2+)-bearing olivine were isolated in a Ta capsule, no quasicrystals were found. However, with only metallic starting materials, numerous micron-sized five-component icosahedral quasicrystals, average composition Al_(72)Cu_(12)Fe_(12)Cr_3Ni_1, were found at the interface between CuAl_5 and stainless steel, demonstrating nucleation of quasicrystals under shock without any redox reaction. We present detailed characterization of recovered quasicrystals and discuss possible mechanisms for generating sufficiently high temperatures to reach melting with relatively weak shocks. We discuss the implications of our five-component quasicrystal for the stability of quasicrystals, which have previously only been considered in alloy systems with four or fewer components. Even small amounts of additional metals expand the stability range of the icosahedral phase and facilitate routine syntheses without extraordinary precision in preparation of starting mixtures.",
"doi": "10.1038/s41598-017-15771-1",
"pmcid": "PMC5688125",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2017-11-15",
"volume": "7",
"pages": "Art. No. 15629"
},
{
"id": "authors:2gp99-bm669",
"collection": "authors",
"collection_id": "2gp99-bm669",
"cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171115-104605836",
"type": "article",
"title": "Shock Synthesis of Decagonal Quasicrystals",
"author": [
{
"family_name": "Oppenheim",
"given_name": "J.",
"orcid": "0000-0002-5988-0677",
"clpid": "Oppenheim-Julius-J"
},
{
"family_name": "Ma",
"given_name": "C.",
"orcid": "0000-0002-1828-7033",
"clpid": "Ma-Chi-Geology"
},
{
"family_name": "Hu",
"given_name": "J.",
"orcid": "0000-0003-0415-4616",
"clpid": "Hu-Jinping"
},
{
"family_name": "Bindi",
"given_name": "L.",
"orcid": "0000-0003-1168-7306",
"clpid": "Bindi-Luca"
},
{
"family_name": "Steinhardt",
"given_name": "P. J.",
"clpid": "Steinhardt-Paul-J"
},
{
"family_name": "Asimow",
"given_name": "P. D.",
"orcid": "0000-0001-6025-8925",
"clpid": "Asimow-P-D"
}
],
"abstract": "The Khatyrka meteorite contains both icosahedral and decagonal quasicrystals. In our previous studies, icosahedral quasicrystals have been synthesized and recovered from shock experiments at the interface between CuAl_5 and stainless steel 304 alloys. In this study, we report a new shock recovery experiment aimed at synthesizing decagonal quasicrystals similar to decagonite, natural Al_(71)Ni_(24)Fe_5. Aluminum 2024 and permalloy 80 alloys were stacked together and shocked in a stainless steel 304 recovery chamber. Abundant decagonal quasicrystals of average composition Al_(73)Ni_(19)Fe_4Cu_2Mg_(0.6)Mo_(0.4)Mn_(0.3) with traces of Si and Cr were found along the recovered interface between the Al and permalloy. The experiment also synthesized AlNiFe alloy with the B2 (CsCl-type) structure and the metastable Al_9Ni_2 phase. We present chemical (scanning electron microscopy and electron microprobe) and structural (electron backscatter diffraction and transmission electron microscopy) characterization of the recovered phases and discuss the implications of this shock synthesis for the stability of quasicrystals during high-pressure shocks and for the interpretation of the phase assemblage found in Khatyrka.",
"doi": "10.1038/s41598-017-15229-4",
"pmcid": "PMC5688080",
"issn": "2045-2322",
"publisher": "Nature Publishing Group",
"publication": "Scientific Reports",
"publication_date": "2017-11-15",
"volume": "7",
"pages": "Art. No. 15628"
}
]