[ { "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.

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Characterisation 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: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:q1ywh-n3e45", "collection": "authors", "collection_id": "q1ywh-n3e45", "cite_using_url": "https://authors.library.caltech.edu/records/q1ywh-n3e45", "type": "article", "title": "Rotherkopfite, KNa\u2082(Fe\u00b2\u207a2.5Ti\u2074\u207a1.5)Fe\u00b2\u207a(Si\u2084O\u2081\u2082)\u2082, a new neptunite-group mineral without essential lithium, from Rother Kopf, Eifel volcanic fields, Germany", "author": [ { "family_name": "Kampf", "given_name": "Anthony R.", "orcid": "0000-0001-8084-2563" }, { "family_name": "M\u00f6hn", "given_name": "Gerhard" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "D\u00e9sor", "given_name": "Joy" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "

Rotherkopfite, KNa2(Fe2.52+Ti1.54+)Fe2+(Si4O12)2, is a new member of the neptunite group, from Rother Kopf, Roth, near Gerolstein, Eifel volcanic fields, Rhineland-Palatinate, Germany. It is found in cavities in a quartz–sanidine xenolith embedded in a vesicular alkaline basalt and is associated with fluorophlogopite and an amphibole supergroup mineral that is zoned from potassic-magnesio-fluoro-arfvedsonite on the exterior to potassic-fluoro-richterite in the core. It is presumed to have formed as the result of contact metasomatism of the xenolith by the alkaline basalt melt. Rotherkopfite occurs as brownish-red equant or tabular crystals, up to about 0.2 mm in maximum dimension. The mineral has a light-orange streak, a vitreous lustre, a Mohs hardness of ∼4.5, a brittle tenacity, a curved fracture and a density of 3.20(2) g cm−3. Optically, rotherkopfite crystals are biaxial (+), with α=1.668(5), β=1.678(5), γ=1.720(5) (white light) and 2V(meas) = 53.2(6)°. The empirical formula from electron microprobe analyses, secondary ion mass spectrometry and structure refinement is (K0.87Na0.20)Σ1.07(Na1.99Ca0.01)Σ2.00M1+M2(Fe1.662+Ti1.48Mg0.79Mn0.02)Σ3.95M3(Fe0.642+Li0.16Ti0.15Al0.01)Σ0.96(Si8.00O24). Rotherkopfite is monoclinic with space group C2/c and unit-cell parameters a=16.4599(17), b=12.5457(6), c=10.0487(7) Å, β=115.669(7)°, V=1870.3(3) Å3 and Z=4. The crystal structure (R1=0.0268 for 1324 reflections with I>2σI) is based on two interwoven three-dimensional frameworks: (1) a silicate framework made up of pyroxene-like chains of corner-sharing SiO4 tetrahedra and (2) an octahedral framework made up of chains of edge-sharing metal–oxygen octahedra. The two interwoven frameworks are bound to one another by corner sharing. K and Na are hosted in channels in the combined framework.

", "doi": "10.5194/ejm-36-605-2024", "issn": "1617-4011", "publisher": "European Geosciences Union", "publication": "European Journal of Mineralogy", "publication_date": "2024-08-19", "series_number": "4", "volume": "36", "issue": "4", "pages": "605-614" }, { "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": "
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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.

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", "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:yczfp-w7c28", "collection": "authors", "collection_id": "yczfp-w7c28", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-205876300.12", "type": "article", "title": "Coherent tracer correlations in deep-sea corals and implications for biomineralization mechanisms underlying vital effects", "author": [ { "family_name": "Chen", "given_name": "Sang", "orcid": "0000-0001-8941-0791", "clpid": "Chen-Sang" }, { "family_name": "Littley", "given_name": "Eloise F. M.", "orcid": "0000-0003-1442-7585", "clpid": "Littley-Eloise-F-M" }, { "family_name": "Rae", "given_name": "James W. B.", "orcid": "0000-0003-3904-2526", "clpid": "Rae-James-W-B" }, { "family_name": "Charles", "given_name": "Christopher D.", "clpid": "Charles-Christopher-D" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Adkins", "given_name": "Jess F.", "orcid": "0000-0002-3174-5190", "clpid": "Adkins-J-F" } ], "abstract": "Deep-sea corals are a useful archive of thermocline, intermediate, and deep waters in past oceans. However, application of traditional oceanographic tracers to deep-sea corals remains a challenge due to our insufficient understanding of their \"vital effects\". Deep-sea corals are ideal test organisms to study the mechanism underlying vital effects generally, due to the large tracer gradients in individual corals living under relatively constant environmental conditions. Lessons learned from these corals might apply to other scleractinia and to marine calcifiers more generally. Here we present stable isotope, minor and trace metal (Me/Ca ratios) data in a suite of modern Desmophyllum dianthus specimens, collected over multiple spatial scales in individual corals (bulk, micromill, SIMS, NanoSIMS), with multi-proxy analyses made on the same material whenever possible. Spatially coherent Me/Ca correlations are observed in the fibrous aragonite of individual corals, including positive correlations between Mg/Ca, Li/Ca and B/Ca, as well as negative correlations between Mg/Ca and Sr/Ca, consistent with previous studies. We also for the first time document strong correlations between the isotopic (\u03b4\u00b9\u2078O and \u03b4\u00b9\u00b3C) and elemental compositions of the skeletons, most notably a negative correlation between \u03b4\u00b9\u2078O and Mg/Ca. The centers of calcification (COCs) in the coral skeletons show distinct tracer correlations from the aragonite fibers that possibly reflect a more complicated formation mechanism. We interpret the spatially coherent tracer correlations in deep-sea corals with a numerical model of coral calcification previously developed for stable isotopes that considers the role of the enzyme carbonic anhydrase in the calcification processs. With the carbonate chemistry in the model constrained by the stable isotope data, we are able to explain the observed Me/Ca correlations as well as their range of variability, as a result of internal pH elevation in the extracellular calcifying fluid (ECF) of the corals with limited Ca-pumping through the calicoblastic membrane. In particular, the positive Mg/Ca\u2013B/Ca correlation in the fibrous aragonite suggests a borate (B(OH)\u2084\u2013) substitution for carbonate ion (CO\u2083\u00b2\u207b) incorporation mechanism in biogenic aragonite. We also suggest the growth rate dependence of the incorporation of minor and trace elements based conceptually on an ion-by-ion growth model may help explain the absolute Me/Ca values in biogenic aragonites. Finally, we generally find more limited tracer variability in corals from undersaturated seawater compared to their counterparts from supersaturated conditions, suggesting a limit to their internal pH elevation in response to this environmental stress. Understanding the biomineralization mechanisms underlying the vital effects is important for better use of these tracers for paleoceanographic applications, and may shed light on the response of marine calcification to future ocean acidification.", "doi": "10.1016/j.gca.2022.12.006", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2023-02-15", "volume": "343", "pages": "304-322" }, { "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:05hsx-m5c72", "collection": "authors", "collection_id": "05hsx-m5c72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210511-101552611", "type": "article", "title": "Manganese oxides in Martian meteorites Northwest Africa (NWA) 7034 and 7533", "author": [ { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Fischer", "given_name": "Woodward W.", "orcid": "0000-0002-8836-3054", "clpid": "Fischer-W-W" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Beckett", "given_name": "John R.", "clpid": "Beckett-John-R" }, { "family_name": "Tschauner", "given_name": "Oliver", "orcid": "0000-0003-3364-8906", "clpid": "Tschauner-Oliver" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Lingappa", "given_name": "Usha F.", "orcid": "0000-0001-5691-6788", "clpid": "Lingappa-Usha-F" }, { "family_name": "Webb", "given_name": "Samuel M.", "orcid": "0000-0003-1188-0464", "clpid": "Webb-Samuel-M" }, { "family_name": "Prakapenka", "given_name": "Vitali B.", "orcid": "0000-0001-9270-2330", "clpid": "Prakapenka-Vitali-B" }, { "family_name": "Lanza", "given_name": "Nina L.", "orcid": "0000-0003-4445-7996", "clpid": "Lanza-Nina-L" }, { "family_name": "Agee", "given_name": "Carl B.", "clpid": "Agee-Carl-B" } ], "abstract": "We report the discovery of indigenous Mn-oxides in Martian regolith breccias Northwest Africa (NWA) 7034 and 7533. These Mn-oxides occur in Mn-rich regions as nanocrystals mixed with silicates, FeOOH, and possible phosphates. The Mn-rich regions contain up to 34 wt% Mn and typically display large chemical gradients on the scale of 10\u201320 \u03bcm. The Martian origin of Mn-oxides was established by the presence of Mn-rich glass (4.8\u20135.6 wt% Mn) in the fusion crust that crosscuts a Mn-oxides-bearing monzonite clast and by the absence of Mn-oxides on the environmentally exposed surfaces (exterior and fractures) of the meteorites. Manganese K-edge X-ray absorption spectrum (XAS) of the Mn-rich glass in the fusion crust indicated that this glass included high-valent Mn species. Synchrotron micro-X-ray diffraction of a Mn-rich region in a basalt clast and XAS of Mn-rich regions in three monzonite clasts indicate Mn-oxides in these regions are dominantly hollandite-structured with 67\u201385 mol% of the total Mn being Mn4+. The fact that Mn-rich regions are present in diverse petrological associations but are absent in the matrix of the breccias indicates that the Mn-oxides formed through surface alteration prior to the final brecciation event that assembled NWA 7034 and 7533. Thus, the age of the Mn-oxides is older than the lithification age (arguably 1.35 Ga) of NWA 7034 and 7533. Together with findings of Mn-rich phases within Noachian and Hesperian sedimentary strata in Endeavour and Gale craters, our results suggest that Mn-oxides are a common weathering product on Mars, suggesting aqueous environment on the Martian surface with high redox potential.", "doi": "10.1016/j.icarus.2021.114471", "issn": "0019-1035", "publisher": "Elsevier", "publication": "Icarus", "publication_date": "2021-08", "volume": "364", "pages": "Art. No. 114471" }, { "id": "authors:cxz06-k0293", "collection": "authors", "collection_id": "cxz06-k0293", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200923-103012900", "type": "article", "title": "Accurate Trace Element Reporting in Corundum: Development of Secondary Ion Mass Spectrometry Relative Sensitivity Factors", "author": [ { "family_name": "Stone\u2010Sundberg", "given_name": "Jennifer L.", "clpid": "Stone\u2010Sundberg-Jennifer-L" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Sun", "given_name": "Ziyin", "clpid": "Sun-Ziyin" }, { "family_name": "Ardon", "given_name": "Troy", "clpid": "Ardon-Troy" } ], "abstract": "The attractive physical and chemical properties of corundum lend to this material's importance in both its natural and synthetic forms. However, much of the quantitative work performed on this material is plagued by unknown inaccuracy as non\u2010matrix matched reference materials are used. To conduct accurate quantitative analysis using SIMS, matrix\u2010specific relative sensitivity factors (RSFs) were determined for eighteen trace elements in corundum using dose\u2010verified ion\u2010implants. The RSF values ranged from 2.56 \u00d7 10\u00b2\u00b2 cm\u207b\u00b9 to 3.29 \u00d7 10\u00b2\u2074 with total combined uncertainty values ranging from 7\u201310%. The RSF values, which are related to ionisation potentials, showed trends consistent with expectations for an insulating oxide. The developed values were applied to calibrate reference materials for LA\u2010ICP\u2010MS and to study other natural and synthetic corundum samples. A measurement reference material calibrated for Mg, Si, Ti, V, Fe and Ga produced consistent results over ten sessions in four years with relative standard deviations per trace element of 5% or less, confirming the repeatability of our process. A key finding was that calibrating LA\u2010ICP\u2010MS with NIST SRM 610 and 612 glasses to analyse corundum resulted in under\u2010reporting trace elements Be, Ti, V, Fe, Co, Ni and Ga compared with using matrix\u2010matched reference materials.", "doi": "10.1111/ggr.12360", "issn": "1639-4488", "publisher": "Association Scientifique", "publication": "Geostandards and Geoanalytical Research", "publication_date": "2021-03", "series_number": "1", "volume": "45", "issue": "1", "pages": "207-221" }, { "id": "authors:6e1qs-j0719", "collection": "authors", "collection_id": "6e1qs-j0719", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210121-101410476", "type": "article", "title": "Elemental Abundances of Major Elements in the Solar Wind as Measured in Genesis Targets and Implications on Solar Wind Fractionation", "author": [ { "family_name": "Heber", "given_name": "Veronika S.", "clpid": "Heber-Veronika-S" }, { "family_name": "McKeegan", "given_name": "Kevin D.", "orcid": "0000-0002-1827-729X", "clpid": "McKeegan-Kevin-D" }, { "family_name": "Steele", "given_name": "Robert C. J.", "orcid": "0000-0003-1406-6855", "clpid": "Steele-Robert-C-J" }, { "family_name": "Jurewicz", "given_name": "Amy J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-AmyJ-G" }, { "family_name": "Rieck", "given_name": "Karen D.", "orcid": "0000-0002-7427-9134", "clpid": "Rieck-Karen-D" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wieler", "given_name": "Rainer", "orcid": "0000-0001-5666-7494", "clpid": "Wieler-Rainer" }, { "family_name": "Burnett", "given_name": "Donald S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" } ], "abstract": "We present elemental abundance data of C, N, O, Na, Mg, Al, Ca, and Cr in Genesis silicon targets. For Na, Mg, Al, and Ca, data from three different solar wind (SW) regimes are also presented. Data were obtained by backside depth profiling using secondary ion mass spectrometry. The accuracy of these measurements exceeds those obtained by in situ observations; therefore, the Genesis data provide new insights into elemental fractionation between Sun and SW, including differences between SW regimes. We integrate previously published noble gas and hydrogen elemental abundances from Genesis targets, as well as preliminary values for K and Fe. The abundances of the SW elements measured display the well-known fractionation pattern that correlates with each element's first-ionization potential (FIP). When normalized either to spectroscopic photospheric solar abundances or to those derived from CI-chondritic meteorites, the fractionation factors of low-FIP elements (K, Na, Al, Ca, Cr, Mg, Fe) are essentially identical within uncertainties, but the data are equally consistent with increasing fractionation with decreasing FIP. The elements with higher FIPs between ~11 and ~16 eV (C, N, O, H, Ar, Kr, Xe) display a relatively well-defined trend of increasing fractionation with decreasing FIP, if normalized to modern 3D photospheric model abundances. Among the three Genesis regimes, the fast SW displays the least elemental fractionation for almost all elements (including the noble gases) but differences are modest: for low-FIP elements, the precisely measured fast\u2013slow SW variations are less than 3%.", "doi": "10.3847/1538-4357/abc94a", "pmcid": "PMC8350966", "issn": "1538-4357", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2021-01-20", "series_number": "1", "volume": "907", "issue": "1", "pages": "Art. No. 15" }, { "id": "authors:w6rjw-x8g29", "collection": "authors", "collection_id": "w6rjw-x8g29", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20210205-145940906", "type": "article", "title": "Quantifying low fluence ion implants in diamond-like carbon film by secondary ion mass spectrometry by understanding matrix effects", "author": [ { "family_name": "Jurewicz", "given_name": "Amy J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-AmyJ-G" }, { "family_name": "Olinger", "given_name": "Chad T.", "orcid": "0000-0002-9509-6345", "clpid": "Olinger-Chad-T" }, { "family_name": "Burnett", "given_name": "Donald S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hervig", "given_name": "Richard", "orcid": "0000-0001-7892-5423", "clpid": "Hervig-Richard" }, { "family_name": "Rieck", "given_name": "Karen D.", "orcid": "0000-0002-7427-9134", "clpid": "Rieck-Karen-D" }, { "family_name": "Woolum", "given_name": "Dorothy S.", "orcid": "0000-0002-4461-0906", "clpid": "Woolum-Dorothy-S" } ], "abstract": "Minor and trace elements in diamond-like carbon (DLC) are difficult to quantify using SIMS analysis because minor elemental and structural variations can result in major matrix effects even across individual, cm-sized samples. While this material is most commonly used for tribological coatings where minor element composition is not of critical importance, it is being increasingly used in electronic devices. However, it is a unique application that spurred this work: anhydrous, tetrahedrally-coordinated DLC (ta-C) was used as a solar wind (SW) collector material in the Genesis solar-wind sample return mission (NASA Discovery 5). So, for \u223c15 years, we have been working on attaining accurate and precise measurement of minor and trace elements in the Genesis DLC using SIMS to achieve our mission goals. Specifically, we have learned to deal with relevant matrix effects in our samples, ion implants into ta-C. Our unknown element for quantification is SW Mg, a low-dose (1.67 \u00d7 10\u00b9\u00b2 at cm\u207b\u00b2; \u223c6 \u03bcg g\u207b\u00b9 \u00b2\u2074Mg), low-energy (\u223c24 keV average energy) implant; our standard is a high-dose (\u223c1 \u00d7 10\u00b9\u2074 at cm\u207b\u00b2 of both \u00b2\u2075Mg, \u00b2\u2076Mg) 75 keV laboratory implant for which the absolute \u00b2\u2076Mg/\u00b2\u2075Mg ratio had been measured to account for variable instrumental mass fractionation. Analyses were performed using O\u2082\u207a primary ions having both a low impact energy and a current density of \u223c2 \u00d7 10\u00b9\u2074 ions per cm\u00b2. Although our unknown was solar wind, the method is applicable to many situations where minor elements in DLC need to be quantified. Recommendations are presented for modifying this data-reduction technique for other SIMS conditions.", "doi": "10.1039/d0ja00375a", "issn": "0267-9477", "publisher": "Royal Society of Chemistry", "publication": "Journal of Analytical Atomic Spectrometry", "publication_date": "2021-01-01", "series_number": "1", "volume": "36", "issue": "1", "pages": "194-209" }, { "id": "authors:8f81e-ynm02", "collection": "authors", "collection_id": "8f81e-ynm02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200608-133209595", "type": "article", "title": "Electron Microprobe/SIMS Determinations of Al in Olivine: Applications to Solar Wind, Pallasites and Trace Element Measurements", "author": [ { "family_name": "Paque", "given_name": "Julie M.", "orcid": "0000-0003-0554-7876", "clpid": "Paque-J-M" }, { "family_name": "Hofmann", "given_name": "Amy E.", "clpid": "Hofmann-A-E" }, { "family_name": "Burnett", "given_name": "Donald S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Jurewicz", "given_name": "Amy J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-A-J-G" }, { "family_name": "Woolum", "given_name": "Dorothy S.", "clpid": "Woolum-D-S" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" } ], "abstract": "Electron probe microanalyser measurements of trace elements with high accuracy are challenging. Accurate Al measurements in olivine are required to calibrate SIMS implant reference materials for measurement of Al in the solar wind. We adopt a combined EPMA/SIMS approach that is useful for producing SIMS reference materials as well as for EPMA at the ~100 \u00b5g g\u207b\u00b9 level. Even for mounts not polished with alumina photoelectron spectroscopy shows high levels of Al surface contamination. In order to minimise electron beam current density, a rastered 50 \u00d7 100 \u00b5m electron beam was adequate and minimised sensitivity to small Al\u2010rich contaminants. Reproducible analyses of eleven SIMS cleaned spots on San Carlos olivine agreed at 69.3 \u00b1 1.0 \u00b5g g\u207b\u00b9. The known Al mass fraction was used to calibrate an Al implant into San Carlos. Accurate measurements of Al were made for olivines in the pallasites: Imilac, Eagle Station and Springwater. Our focus was on Al in olivine; but our technique could be refined to give accurate electron probe measurements for other contamination\u2010sensitive trace elements. For solar wind it is projected that the Al/Mg abundance ratio can be determined to 6%, a factor of 2 more precise than the solar spectroscopic ratio.", "doi": "10.1111/ggr.12347", "issn": "1639-4488", "publisher": "Wiley", "publication": "Geostandards and Geoanalytical Research", "publication_date": "2020-09", "series_number": "3", "volume": "44", "issue": "3", "pages": "473-484" }, { "id": "authors:z10mw-zq376", "collection": "authors", "collection_id": "z10mw-zq376", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200206-112311510", "type": "article", "title": "Magnesium isotopes of the bulk solar wind from Genesis diamond\u2010like carbon films", "author": [ { "family_name": "Jurewicz", "given_name": "A. J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-Amy-J-G" }, { "family_name": "Rieck", "given_name": "K. D.", "clpid": "Rieck-K-D" }, { "family_name": "Hervig", "given_name": "R.", "orcid": "0000-0001-7892-5423", "clpid": "Hervig-Richard" }, { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Wadhwa", "given_name": "M.", "orcid": "0000-0001-9187-1255", "clpid": "Wadhwa-Meenakshi" }, { "family_name": "Olinger", "given_name": "C. T.", "orcid": "0000-0002-9509-6345", "clpid": "Olinger-Chad-T" }, { "family_name": "Wiens", "given_name": "R. C.", "orcid": "0000-0002-3409-7344", "clpid": "Wiens-Roger-C" }, { "family_name": "Laming", "given_name": "J. M.", "orcid": "0000-0002-3362-7040", "clpid": "Laming-J-Martin" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Huss", "given_name": "G. R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-Gary-R" }, { "family_name": "Reisenfeld", "given_name": "D. B.", "orcid": "0000-0003-1874-9450", "clpid": "Reisenfeld-Daniel-B" }, { "family_name": "Williams", "given_name": "P.", "clpid": "Williams-P" } ], "abstract": "NASA's Genesis Mission returned solar wind (SW) to the Earth for analysis to derive the composition of the solar photosphere from solar material. SW analyses control the precision of the derived solar compositions, but their ultimate accuracy is limited by the theoretical or empirical models of fractionation due to SW formation. Mg isotopes are \"ground truth\" for these models since, except for CAIs, planetary materials have a uniform Mg isotopic composition (within \u22641\u2030) so any significant isotopic fractionation of SW Mg is primarily that of SW formation and subsequent acceleration through the corona. This study analyzed Mg isotopes in a bulk SW diamond\u2010like carbon (DLC) film on silicon collector returned by the Genesis Mission. A novel data reduction technique was required to account for variable ion yield and instrumental mass fractionation (IMF) in the DLC. The resulting SW Mg fractionation relative to the DSM\u20103 laboratory standard was (\u221214.4\u2030, \u221230.2\u2030) \u00b1 (4.1\u2030, 5.5\u2030), where the uncertainty is 2\u01a1 SE of the data combined with a 2.5\u2030 (total) error in the IMF determination. Two of the SW fractionation models considered generally agreed with our data. Their possible ramifications are discussed for O isotopes based on the CAI nebular composition of McKeegan et al. (2011).", "doi": "10.1111/maps.13439", "pmcid": "PMC7079557", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2020-02", "series_number": "2", "volume": "55", "issue": "2", "pages": "352-375" }, { "id": "authors:a4ehj-7w937", "collection": "authors", "collection_id": "a4ehj-7w937", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190607-080718714", "type": "article", "title": "Effects of pH_2O, pH_2 and fO_2 on the diffusion of h-bearing species in lunar basaltic liquid and an iron-free basaltic analog at 1 atm", "author": [ { "family_name": "Newcombe", "given_name": "M. E.", "orcid": "0000-0002-8450-768X", "clpid": "Newcombe-M-E" }, { "family_name": "Beckett", "given_name": "J. R.", "clpid": "Beckett-J-R" }, { "family_name": "Baker", "given_name": "M. B.", "clpid": "Baker-M-B" }, { "family_name": "Newman", "given_name": "S.", "orcid": "0000-0003-0710-995X", "clpid": "Newman-S" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Stolper", "given_name": "E. M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "We have experimentally determined the diffusivity of water in a representative lunar basaltic liquid composition (LG) and in an iron-free analog of a basaltic liquid (AD) at the low water concentrations and low oxygen fugacities (fO_2) relevant to the eruption of lunar basalts. Experiments were conducted at 1 atm and 1350 \u00b0C over a range of pH_2/pH_2O from near zero to \u223c10 and a range in fO_2 spanning \u223c9 orders of magnitude (from 2.2 log units below the iron-w\u00fcstite buffer, IW\u20132.2, to IW+6.7). The water concentrations measured in our quenched experimental glasses by secondary ion mass spectrometry (SIMS) and Fourier transform infrared spectroscopy (FTIR) vary from a few ppm to \u223c430 ppm. Water concentration gradients in the majority of our AD experiments are well described by models in which the diffusivity of water (D*_(water)) has a constant value of \u223c2\u00d710^(\u201310) m^2/s, while our LG results indicate that D*_(water) in LG melt has a constant value of \u223c6\u00d710^(\u201310) m^2/s under the conditions of our experiments. Water concentration gradients in hydration and dehydration experiments that were run simultaneously in H_2/CO_2 gas mixtures are well described by the same D*_(water), and water concentrations measured near the melt-vapor interfaces of these experiment pairs are approximately the same. These observations strongly support an equilibrium boundary condition for our experiments containing >70 ppm H_2O. However, dehydration experiments into nominally anhydrous CO_2, N_2, and CO/CO_2 gas mixtures leave some scope for the importance of kinetics during dehydration of melts containing less than a few 10's of ppm H_2O. Comparison of our results with the modified speciation model (Ni et al., 2013) in which both molecular water and hydroxyl are allowed to diffuse suggests that we have resolved the diffusivity of hydroxyl (D_(OH)) in AD and LG melts. Our results support a positive correlation between D_(OH) and melt depolymerization. Best-fit values of D*_(water) for our LG experiments vary within a factor of \u223c2 over a range of pH_2/pH_2O from 0.007 to 9.7 and a range of logf O_2 from IW\u20132.2 to IW+4.9. The relative insensitivity of our best-fit values of D*_(water) to variations in pH_2 suggests that H_2 diffusion did not control the rate of degassing of H-bearing species from the lunar glasses of Saal et al. (2008); however, we cannot rule out a role for molecular H2 diffusion under lower-temperature and/or higher-pressure conditions than explored in our experiments. The value of D*_(water) chosen by Saal et al. (2008) for modeling the diffusive degassing of the lunar volcanic glasses is within a factor of \u223c2 of our measured value in LG melt at 1350 \u00b0C. By coupling our LG results at 1350 \u00b0C with an activation energy of 220 kJ/mol (Zhang et al. 2017), we obtain the following Arrhenius relationship, which can be used to model syneruptive diffusive water loss from lunar melt beads:\nD*_(water)(m^2/s) = 7.2\u00d710^(-3)exp(-2.6\u00d710^4/T(K)).", "doi": "10.1016/j.gca.2019.05.033", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2019-08-15", "volume": "259", "pages": "316-343" }, { "id": "authors:1rfws-an196", "collection": "authors", "collection_id": "1rfws-an196", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190405-094702265", "type": "article", "title": "An extremely heavy chlorine reservoir in the Moon: Insights from the apatite in lunar meteorites", "author": [ { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Chlorine, an extremely hydrophilic volatile element, provides important information regarding the origin of intrinsic volatiles in the Moon. Lunar apatite was found to have a wider spread of \u03b4^(37)Cl (from \u22121 to +40\u2030 versus standard mean ocean chloride) than most terrestrial and chondritic ones (0\u2009\u00b1\u20090.5\u2030). However, the provenance of the elevated lunar \u03b4^(37)Cl is still enigmatic. Here we report new isotopic data for H and Cl in apatite from three lunar meteorites and discuss possible mechanisms for Cl isotopic fractionation of the Moon. The apatite grain in Dhofar 458 has an average \u03b4^(37)Cl value of +76\u2030, indicative of an extremely heavy Cl reservoir in the Moon. Volatile loss associated with the Moon-forming Giant Impact and the formation of lunar magma ocean could account for the large Cl isotopic fractionation of the Moon. The observed H_2O contents (220\u20135200 ppm), \u03b4D (\u2212100 to +550\u2030) and \u03b4^(37)Cl values (+3.8\u2009\u2212\u2009+81.1\u2030) in lunar apatite could be understood if late accretion of hydrous components were added to the Moon after the fractionation of Cl isotopes. The heterogeneous distribution of lunar Cl isotopes is probably resulted from complex lunar formation and differentiation processes.", "doi": "10.1038/s41598-019-42224-8", "pmcid": "PMC6450942", "issn": "2045-2322", "publisher": "Nature Publishing Group", "publication": "Scientific Reports", "publication_date": "2019-04-05", "volume": "9", "pages": "Art. No. 5727" }, { "id": "authors:zs8j8-n1p88", "collection": "authors", "collection_id": "zs8j8-n1p88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190123-094132030", "type": "article", "title": "Discovery of native aluminum on Variscan metagranitoids in Upper Carinthia, Austria: natural or anthropogenic origin?", "author": [ { "family_name": "Paar", "given_name": "Werner H.", "clpid": "Paar-Werner-H" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Topa", "given_name": "Dan", "clpid": "Topa-Dan" }, { "family_name": "Culetto", "given_name": "Franz J.", "clpid": "Culetto-Franz-J" }, { "family_name": "Hammer", "given_name": "Vera F. M.", "clpid": "Hammer-Vera-F-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Braithwaite", "given_name": "Richard S. W.", "clpid": "Braithwaite-Richard-S-W" } ], "abstract": "Native aluminum was discovered in 2004 at Hochwurten, Goldberg mountain group, Upper Carinthia, Austria. The discovery site is close to the Wurtenkees (glacier), where the dominant rock (Central gneiss) was exposed during the retreat of the glacier. Here, also veins with gold-bearing ores associated with tellurides (tetradymite, tsumoite, jos\u00e9ite-A) and Ag\u2013Pb\u2013Bi-sulfosalts are exposed and were mined intermittently during the last centuries. Native aluminum occurs at some distance (several 100 m laterally and vertically) to the veins as an isolated crystalline aggregate measuring 10\u2009\u00d7\u20093 mm, and a closely associated flake (200 \u00b5m length), which was used for most of the studies. Both occur on gneiss and are intensely intergrown with it. Two groups of inclusions in the aluminum were observed and studied by SEM and EPMA. Group one consists of Bi\u2013Te\u2013(S)\u2013(O) minerals, such as tetradymite, Bi2Te2S, tsumoite, BiTe, tellurobismuthite, Bi_2Te_3, bismuth and a montanite-type secondary mineral. The other group contains a new phase with composition (Al,Si)_(19)Fe_4, rare grains of hollisterite (Al_3Fe), and abundant Zn,Mg-bearing metallic nano-phases. A transition zone is developed between native aluminum and albite, a constituent of the gneiss, and is characterized by strongly changing concentrations of aluminum, silicon, iron and sulfur. Micro-computed tomography studies reveal that the Al metal is clearly intermixed with the host rock and not just juxtaposed over it. To shed further light on the origin of the Al metal, SIMS Mg isotopic measurements were carried out on the Austrian aluminum and on selected synthetic alloys with similar composition. A thorough discussion about the possible naturalness of this native aluminum and its possible formation is presented. The paper aims at augmenting the rare, assured knowledge of native metal formation/alteration under crustal and subcrustal conditions.", "doi": "10.1007/s12210-019-00760-5", "issn": "2037-4631", "publisher": "Springer", "publication": "Rendiconti Lincei. Scienze Fisiche e Naturali", "publication_date": "2019-03", "series_number": "1", "volume": "30", "issue": "1", "pages": "167-184" }, { "id": "authors:7xzz4-0hc96", "collection": "authors", "collection_id": "7xzz4-0hc96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180327-081337793", "type": "article", "title": "Impact-melt hygrometer for Mars: The case of shergottite Elephant Moraine (EETA) 79001", "author": [ { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Chen", "given_name": "Yang", "clpid": "Chen-Yang-JPL" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" } ], "abstract": "We report volatile concentrations and hydrogen isotope compositions of impact melts and minerals in EETA 79001. We observed chemical changes in pyroxene, maskelynite (or feldspathic glass), and merrillite in contact with or inside impact melts. All pyroxene grains analyzed here are inside or close to impact melt pockets and contain 10\u201341 ppm H_2O and enriched in D (\u03b4D=+1729 to +3707\u2030), with the highest values found in a grain enclosed in an impact melt pocket. Maskelynite or feldspathic glass contains 6.3 to 98 ppm H_2O with \u03b4 D values of +1604 to +3938\u2030. The high H_2O and \u03b4D values were obtained in those enclosed inside or in contact with the impact melts, whereas low H_2O content (4 ppm) and terrestrial-like D/H value (\u03b4 D of \u221290\u00b182\u2030) were found in one maskelynite grain away from impact melts contains. Rims of \u223c5 \u03bcm thickness of merrillite grains next to impact melts display Na-depletion by \u223c0.9 wt%, and the sides in contact with impact melts show Mg-enrichment by \u223c0.5 wt%. However, the H_2O and \u03b4D values of merrillite interiors (39\u2013242 ppm H_2O and \u03b4 D of +1682 to +3884\u2030) do not show correlation with their proximity to the impact melts. Rather, \u03b4D and 1/H_2O of merrillite form a negative trend different from that of impact melt pockets and maskelynite, suggesting post-crystallization or late-crystallization interactions with the crustal fluids.\nThe impact melt pockets in EETA 79001 contain 121\u2013646 ppm H_2O, 4.3\u201313 ppm F, 13\u201350 ppm Cl, 707\u20132702 ppm S, and the \u03b4 D values of +3368 to +4639\u2030. The correlations between H_2O, F, Cl, P_2O_5, and \u03b4D values of impact melts and feldspathic glass are consistent with mixing between a volatile-rich and high \u03b4 D (+3000 to +5000\u2030) endmember and a volatile-poor and low \u03b4D endmember. The volatile-poor and low \u03b4D endmember is consistent with magmatic volatiles stored in silicates. The volatile-rich and high \u03b4D endmember represents pre-impact alteration materials by subsurface water. Alteration from the subsurface water, equilibrated with the present-day-like Martian atmosphere, occurred after the crystallization of the rock (\u223c170 Ma) and before impact launch (\u223c0.7 Ma). Our conclusion is different from the previous suggestion of an isotopically distinct subsurface water reservoir with a \u03b4 D value of +1000 to +2000\u2030 in EETA 79001. Although heterogeneous subsurface water on Mars is possible, the previous study was likely biased by a limited number of analyses (n=2) and possible terrestrial contamination. The \u03b4 D value of the subsurface source in EETA 79001 is \u223c+4200\u2030, similar to those in the Tissint meteorite (crystallization at \u223c600 Ma, impact launch at \u223c0.7 Ma) and LAR 06319 (crystallization at \u223c200 Ma, impact launch at \u223c3 Ma), suggesting stable water chemistry for the subsurface environment in the last 600 Myrs.", "doi": "10.1016/j.epsl.2018.03.019", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2018-05-15", "volume": "490", "pages": "206-215" }, { "id": "authors:bmec6-p6p93", "collection": "authors", "collection_id": "bmec6-p6p93", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171127-134624207", "type": "article", "title": "Interrogating marine virus-host interactions and elemental transfer with BONCAT and nanoSIMS-based methods", "author": [ { "family_name": "Pasulka", "given_name": "Alexis L.", "clpid": "Pasulka-A-L" }, { "family_name": "Thamatrakoln", "given_name": "Kimberlee", "clpid": "Thamatrakoln-K" }, { "family_name": "Kopf", "given_name": "Sebastian H.", "orcid": "0000-0002-2044-0201", "clpid": "Kopf-S-H" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Poulos", "given_name": "Bonnie", "clpid": "Poulos-B" }, { "family_name": "Moradian", "given_name": "Annie", "orcid": "0000-0002-0407-2031", "clpid": "Moradian-A" }, { "family_name": "Sweredoski", "given_name": "Michael J.", "orcid": "0000-0003-0878-3831", "clpid": "Sweredoski-M-J" }, { "family_name": "Hess", "given_name": "Sonja", "orcid": "0000-0002-5904-9816", "clpid": "Hess-S" }, { "family_name": "Sullivan", "given_name": "Mathew B.", "clpid": "Sullivan-M-B" }, { "family_name": "Bidle", "given_name": "Kay D.", "clpid": "Bidle-K-D" }, { "family_name": "Orphan", "given_name": "Victoria J.", "orcid": "0000-0002-5374-6178", "clpid": "Orphan-V-J" } ], "abstract": "While the collective impact of marine viruses has become more apparent over the last decade, a deeper understanding of virus-host dynamics and the role of viruses in nutrient cycling would benefit from direct observations at the single-virus level. We describe two new complementary approaches - stable isotope probing coupled with nanoscale secondary ion mass spectrometry (nanoSIMS) and fluorescence-based biorthogonal non-canonical amino acid tagging (BONCAT) - for studying the activity and biogeochemical influence of marine viruses. These tools were developed and tested using several ecologically relevant model systems (Emiliania huxleyi/EhV207, Synechococcus sp. WH8101/Syn1, and Escherichia coli/T7). By resolving carbon and nitrogen enrichment in viral particles, we demonstrate the power of nanoSIMS tracer experiments in obtaining quantitative estimates for the total number of viruses produced directly from a particular production pathway (by isotopically labeling host substrates). Additionally, we show through laboratory experiments and a pilot field study that BONCAT can be used to directly quantify viral production (via epifluorescence microscopy) with minor sample manipulation and no dependency on conversion factors. This technique can also be used to detect newly synthesized viral proteins. Together these tools will help fill critical gaps in our understanding of the biogeochemical impact of viruses in the ocean.", "doi": "10.1111/1462-2920.13996", "issn": "1462-2912", "publisher": "Wiley", "publication": "Environmental Microbiology", "publication_date": "2018-02", "series_number": "2", "volume": "20", "issue": "2", "pages": "671-692" }, { "id": "authors:x33e5-t1j21", "collection": "authors", "collection_id": "x33e5-t1j21", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20171206-112123892", "type": "article", "title": "Determining the Elemental and Isotopic Composition of the Pre-solar Nebula from Genesis Data Analysis: The Case of Oxygen", "author": [ { "family_name": "Laming", "given_name": "J. Martin", "orcid": "0000-0002-3362-7040", "clpid": "Laming-J-Martin" }, { "family_name": "Heber", "given_name": "N. S.", "clpid": "Heber-Veronika-S" }, { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hervig", "given_name": "R.", "orcid": "0000-0001-7892-5423", "clpid": "Hervig-Richard-L" }, { "family_name": "Huss", "given_name": "G. R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-Gary-R" }, { "family_name": "Jurewicz", "given_name": "A. J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-Amy-J-G" }, { "family_name": "Koeman-Shields", "given_name": "E. C.", "clpid": "Koeman-Shields-Elizabeth-C" }, { "family_name": "McKeegan", "given_name": "K. D.", "orcid": "0000-0002-1827-729X", "clpid": "McKeegan-Kevin-D" }, { "family_name": "Nittler", "given_name": "L. R.", "orcid": "0000-0002-5292-6089", "clpid": "Nittler-Larry-R" }, { "family_name": "Reisenfeld", "given_name": "D. B.", "orcid": "0000-0003-1874-9450", "clpid": "Reisenfeld-Daniel-B" }, { "family_name": "Rieck", "given_name": "K. D.", "orcid": "0000-0002-7427-9134", "clpid": "Rieck-Karen-D" }, { "family_name": "Wang", "given_name": "J.", "orcid": "0000-0002-7671-2413", "clpid": "Wang-Jianhua" }, { "family_name": "Wiens", "given_name": "R. C.", "orcid": "0000-0002-3409-7344", "clpid": "Wiens-Roger-C" }, { "family_name": "Woolum", "given_name": "D. S.", "orcid": "0000-0002-4461-0906", "clpid": "Woolum-Dorothy-S" } ], "abstract": "We compare element and isotopic fractionations measured in bulk solar wind samples collected by NASA's Genesis mission with those predicted from models incorporating both the ponderomotive force in the chromosphere and conservation of the first adiabatic invariant in the low corona. Generally good agreement is found, suggesting that these factors are consistent with the process of solar wind fractionation. Based on bulk wind measurements, we also consider in more detail the isotopic and elemental abundances of O. We find mild support for an O abundance in the range 8.75\u20138.83, with a value as low as 8.69 disfavored. A stronger conclusion must await solar wind regime-specific measurements from the Genesis samples.", "doi": "10.3847/2041-8213/aa9bf0", "pmcid": "PMC5893144", "issn": "2041-8213", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal Letters", "publication_date": "2017-12-10", "series_number": "1", "volume": "851", "issue": "1", "pages": "Art. No. L12" }, { "id": "authors:4qj5v-0fc87", "collection": "authors", "collection_id": "4qj5v-0fc87", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180308-102353250", "type": "article", "title": "Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards", "author": [ { "family_name": "Stone-Sundberg", "given_name": "Jennifer", "clpid": "Stone-Sundberg-J" }, { "family_name": "Thomas", "given_name": "Timothy", "clpid": "Thomas-Timothy" }, { "family_name": "Sun", "given_name": "Ziyin", "clpid": "Sun-Ziyin" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Cole", "given_name": "Zachary", "clpid": "Cole-Z" }, { "family_name": "Equall", "given_name": "Randy", "clpid": "Equall-R" }, { "family_name": "Emmett", "given_name": "John L.", "clpid": "Emmett-J-L" } ], "abstract": "To improve the accuracy and efficiency of trace element analysis in ruby and sapphire, standards sets containing matrix-matched corundum with targeted levels of beryllium, magnesium, silicon, titanium, vanadium, chromium, iron, and gallium were created. Ultra-high-purity corundum was also incorporated as a \"true matrix zero.\" To our knowledge, these sets contain the most accurate standards for the key trace elements in corundum today. The standards were designed to cover the optimal range of the main trace elements typically characterized in natural ruby and sapphire. Additionally, we were able to accurately quantify silicon in corundum by successfully resolving the ^(28)Si^+ peak from the ^(27)Al^1H^+ peak using the superior mass resolving power of secondary ion mass spectrometry (SIMS) as compared to laser ablation\u2013inductively coupled plasma\u2013quadrupole mass spectrometry (LA-ICP-QMS).", "issn": "0016-626X", "publisher": "Gemological Institute of America", "publication": "Gems and Gemology", "publication_date": "2017-12", "series_number": "4", "volume": "53", "issue": "4", "pages": "438-451" }, { "id": "authors:07tyq-r0m98", "collection": "authors", "collection_id": "07tyq-r0m98", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170926-143414146", "type": "article", "title": "Volatile loss during homogenization of lunar melt inclusions", "author": [ { "family_name": "Ni", "given_name": "Peng", "clpid": "Ni-Peng" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Volatile abundances in lunar mantle are critical factors to consider for constraining the model of Moon formation. Recently, the earlier understanding of a \"dry\" Moon has shifted to a fairly \"wet\" Moon due to the detection of measurable amount of H_2O in lunar volcanic glass beads, mineral grains, and olivine-hosted melt inclusions. The ongoing debate on a \"dry\" or \"wet\" Moon requires further studies on lunar melt inclusions to obtain a broader understanding of volatile abundances in the lunar mantle. One important uncertainty for lunar melt inclusion studies, however, is whether the homogenization of melt inclusions would cause volatile loss. In this study, a series of homogenization experiments were conducted on olivine-hosted melt inclusions from the sample 74220 to evaluate the possible loss of volatiles during homogenization of lunar melt inclusions. Our results suggest that significant loss of H_2O could occur even during minutes of homogenization, while F, Cl and S in the inclusions remain unaffected.\nWe model the trend of H_2O loss in homogenized melt inclusions by a diffusive hydrogen loss model. The model can reconcile the observed experimental data well, with a best-fit H diffusivity in accordance with diffusion data explained by the \"slow\" mechanism for hydrogen diffusion in olivine. Surprisingly, no significant effect for the low oxygen fugacity on the Moon is observed on the diffusive loss of hydrogen during homogenization of lunar melt inclusions under reducing conditions. Our experimental and modeling results show that diffusive H loss is negligible for melt inclusions of >25 \u03bcm radius. As our results mitigate the concern of H_2O loss during homogenization for crystalline lunar melt inclusions, we found that H_2O/Ce ratios in melt inclusions from different lunar samples vary with degree of crystallization. Such a variation is more likely due to H_2O loss on the lunar surface, while heterogeneity in their lunar mantle source is also a possibility. A similar size-dependence trend of H_2O concentrations was also observed in natural unheated melt inclusions in 74220. By comparing the trend of diffusive H loss in the natural MIs and in our homogenized MIs, the cooling rate for 74220 was estimated to be \u223c1\u2009\u00b0C/s or slower.", "doi": "10.1016/j.epsl.2017.09.010", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2017-11-15", "volume": "478", "pages": "214-224" }, { "id": "authors:606z9-ceb43", "collection": "authors", "collection_id": "606z9-ceb43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170613-095839194", "type": "article", "title": "A heterogeneous lunar interior for hydrogen isotopes as revealed by the lunar highlands samples", "author": [ { "family_name": "Hui", "given_name": "Hejiu", "clpid": "Hui-Hejiu" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Chen", "given_name": "Yang", "clpid": "Chen-Yang-JPL" }, { "family_name": "Peslier", "given_name": "Anne H.", "clpid": "Peslier-A-H" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Flemming", "given_name": "Roberta L.", "clpid": "Flemming-Roberta-L" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Neal", "given_name": "Clive R.", "clpid": "Neal-C-R" }, { "family_name": "Osinski", "given_name": "Gordon R.", "clpid": "Osinski-G-R" } ], "abstract": "Knowing the amount and timing of water incorporation into the Moon has fundamental implications for our understanding of how the Earth\u2013Moon system formed. Water has been detected in lunar samples but its abundance, distribution and origin are debated. To address these issues, we report water concentrations and hydrogen isotope ratios obtained by secondary ion mass spectrometry (SIMS) of plagioclase from ferroan anorthosites (FANs), the only available lithology thought to have crystallized directly from the lunar magma ocean (LMO). The measured water contents are consistent with previous results by Fourier transform infrared spectroscopy (FTIR). Combined with literature data, \u03b4D values of lunar igneous materials least-degassed at the time of their crystallization range from \u2212280 to +310\u2030, the latter value being that of FAN 60015 corrected for cosmic ray exposure. We interpret these results as hydrogen isotopes being fractionated during degassing of molecular hydrogen (H_2) in the LMO, starting with the magmatic \u03b4D value of primordial water at the beginning of LMO being about \u2212280\u2030, evolving to about +310\u2030 at the time of anorthite crystallization, i.e. during the formation of the primary lunar crust. The degassing of hydrogen in the LMO is consistent with those of other volatile elements. The wide range of \u03b4D values observed in lunar igneous rocks could be due to either various degrees of mixing of the different mantle end members, or from a range of mantle sources that were degassed to different degrees during magma evolution. Degassing of the LMO is a viable mechanism that resulted in a heterogeneous lunar interior for hydrogen isotopes.", "doi": "10.1016/j.epsl.2017.05.029", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2017-09-01", "volume": "473", "pages": "14-23" }, { "id": "authors:y04e2-rme65", "collection": "authors", "collection_id": "y04e2-rme65", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170509-131410385", "type": "article", "title": "Martian low-temperature alteration materials in shock-melt pockets in Tissint: Constraints on their preservation in shergottite meteorites", "author": [ { "family_name": "Kuchka", "given_name": "C. R.", "clpid": "Kuchka-C-R" }, { "family_name": "Herd", "given_name": "C. D. K.", "clpid": "Herd-C-D-K" }, { "family_name": "Walton", "given_name": "E. L.", "orcid": "0000-0003-1301-5300", "clpid": "Walton-E-L" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Liu", "given_name": "Y.", "clpid": "Liu-Yang-Jace" } ], "abstract": "We apply an array of in situ analytical techniques, including electron and Raman microscopy, electron and ion probe microanalysis, and laser ablation mass spectrometry to the Tissint martian meteorite in order to find and elucidate a geochemical signature characteristic of low-temperature alteration at or near the martian surface. Tissint contains abundant shock-produced quench-crystallized melt pockets containing water in concentrations ranging from 73 to 1730 ppm; water content is positively correlated with Cl content. The isotopic composition of hydrogen in the shock-produced glass ranges from \u03b4D = 2559 to 4422 \u2030. Water is derived from two distinct hydrogen reservoirs: the martian near-surface (>500 \u2030) and the martian mantle (-100 \u2030). In one shock melt pocket comprising texturally homogeneous vesiculated glass, the concentration of H in the shock melt decreases while simultaneously becoming enriched in D, attributable to the preferential loss of H over D to the vesicle while the pocket was still molten. While igneous sulfides are pyrrhotite in composition (Fe_(0.88-0.90)S), the iron to sulfur ratios of spherules in shock melt pockets are elevated, up to Fe_(1.70)S, which we attribute to shock-oxidation of igneous pyrrhotite and the formation of hematite at high temperature. The D- and Cl-enrichment, and higher oxidation of the pockets (as indicated by hematite) support a scenario in which alteration products formed within fractures or void spaces within the rock; the signature of these alteration products is preserved within shock melt (now glass) which formed upon collapse of these fractures and voids during impact shock. Thermal modeling of Tissint shock melt pockets using the HEAT program demonstrates that the shock melt pockets with the greatest potential to preserve a signature of aqueous alteration are small, isolated from other regions of shock melt, vesicle-free, and glassy.", "doi": "10.1016/j.gca.2017.04.037", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2017-08-01", "volume": "210", "pages": "228-246" }, { "id": "authors:gs075-1gb56", "collection": "authors", "collection_id": "gs075-1gb56", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170109-092018124", "type": "article", "title": "Solubility of water in lunar basalt at low pH_2O", "author": [ { "family_name": "Newcombe", "given_name": "M. E.", "orcid": "0000-0002-8450-768X", "clpid": "Newcombe-M-E" }, { "family_name": "Brett", "given_name": "A.", "clpid": "Brett-A-M" }, { "family_name": "Beckett", "given_name": "J. R.", "clpid": "Beckett-J-R" }, { "family_name": "Baker", "given_name": "M. B.", "clpid": "Baker-M-B" }, { "family_name": "Newman", "given_name": "S.", "orcid": "0000-0003-0710-995X", "clpid": "Newman-S" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Stolper", "given_name": "E. M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "We report the solubility of water in Apollo 15 basaltic 'Yellow Glass' and an iron-free basaltic analog composition at 1 atm and 1350 \u00b0C. We equilibrated melts in a 1-atm furnace with flowing H_2/CO_2 gas mixtures that spanned \u223c8 orders of magnitude in fO_2 (from three orders of magnitude more reducing than the iron-w\u00fcstite buffer, IW\u22123.0, to IW+4.8) and \u223c4 orders of magnitude in pH_2/pH_2O (from 0.003 to 24). Based on Fourier transform infrared spectroscopy (FTIR), our quenched experimental glasses contain 69\u2013425 ppm total water (by weight). Our results demonstrate that under the conditions of our experiments: (1) hydroxyl is the only H-bearing species detected by FTIR; (2) the solubility of water is proportional to the square root of pH_2O in the furnace atmosphere and is independent of fO_2 and pH_2/pH_2O; (3) the solubility of water is very similar in both melt compositions; (4) the concentration of H_2 in our iron-free experiments is <\u223c4 ppm, even at oxygen fugacities as low as IW\u22122.3 and pH_2/pH_2O as high as 11; (5) Secondary ion mass spectrometry (SIMS) analyses of water in iron-rich glasses equilibrated under variable fO_2 conditions may be strongly influenced by matrix effects, even when the concentration of water in the glasses is low; and (6) Our results can be used to constrain the entrapment pressure of lunar melt inclusions and the partial pressures of water and molecular hydrogen in the carrier gas of the lunar pyroclastic glass beads. We find that the most water-rich melt inclusion of Hauri et al. (2011) would be in equilibrium with a vapor with pH_2O \u223c3 bar and pH_2 \u223c8 bar. We constrain the partial pressures of water and molecular hydrogen in the carrier gas of the lunar pyroclastic glass beads to be 0.0005 bar and 0.0011 bar respectively. We calculate that batch degassing of lunar magmas containing initial volatile contents of 1200 ppm H_2O (dissolved primarily as hydroxyl) and 4\u201364 ppm C would produce enough vapor to reach the critical vapor volume fraction thought to be required for magma fragmentation (\u223c65\u201375 vol.%) at a total pressure of \u223c5 bar (corresponding to a depth beneath the lunar surface of \u223c120 m). At a fragmentation pressure of \u223c5 bar, the calculated vapor composition is dominated by H_2, supporting the hypothesis that H2, rather than CO, was the primary propellant of the lunar fire fountain eruptions. The results of our batch degassing model suggest that initial melt compositions with >\u223c200 ppm C would be required for the vapor composition to be dominated by CO rather than H_2 at 65\u201375% vesicularity.", "doi": "10.1016/j.gca.2016.12.026", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2017-03-01", "volume": "200", "pages": "330-352" }, { "id": "authors:2k00b-8s419", "collection": "authors", "collection_id": "2k00b-8s419", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170608-075737410", "type": "article", "title": "The Role of Silicon in the Color of Gem Corundum", "author": [ { "family_name": "Emmett", "given_name": "John L.", "clpid": "Emmett-J-L" }, { "family_name": "Stone-Sundberg", "given_name": "Jennifer", "clpid": "Stone-Sundberg-J" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Sun", "given_name": "Ziyin", "clpid": "Sun-Ziyin" } ], "abstract": "Natural corundum is colored by a variety of trace-element impurities and by the chemical reactions among them. Important to nearly all of the colors is the role played by the reactions among silicon, titanium, and magnesium. Characterization of the interactions between these aliovalent ions has been hindered by the fact that the laser ablation\u2013inductively coupled quadrupole\u2013mass spectrometry equipment used in most gem labs does not resolve the interferences for silicon. Thus Si has not been measured at relevant concentrations. Recent development of ion implant standards and the application of secondary ion mass spectrometry has allowed the accurate measurement of silicon in corundum for the first time. As an example of its importance, detailed analyses of sapphire from Montana's Yogo Gulch deposit are presented. These analyses show that without silicon, Yogo sapphire would not be blue.", "doi": "10.5741/GEMS.53.1.42", "issn": "0016-626X", "publisher": "Gemological Institute of America", "publication": "Gems and Gemology", "publication_date": "2017-03", "series_number": "1", "volume": "53", "issue": "1", "pages": "42-47" }, { "id": "authors:tshyd-fte82", "collection": "authors", "collection_id": "tshyd-fte82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170113-160217243", "type": "article", "title": "The effect of crystal-plastic deformation on isotope and trace element distribution in zircon: Combined BSE, CL, EBSD, FEG-EMPA and NanoSIMS study", "author": [ { "family_name": "Kovaleva", "given_name": "Elizaveta", "clpid": "Kovaleva-E" }, { "family_name": "Kl\u00f6tzli", "given_name": "Urs", "clpid": "Kl\u00f6tzli-U" }, { "family_name": "Habler", "given_name": "Gerlinde", "clpid": "Habler-G" }, { "family_name": "Huet", "given_name": "Benjamin", "clpid": "Huet-B" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Rhede", "given_name": "Dieter", "clpid": "Rhede-D" } ], "abstract": "Plastically-deformed zircon grains from granulite-facies (Ivrea-Verbano Zone, Southern Alps, Italy) and amphibolite-facies (Tauern Window, Eastern Alps, Austria) shear zones have been investigated. The main focus was on the effects of crystal-plastic deformation on the distribution of trace elements and their isotopes. Zircon grains reveal crystal-plastic deformation patterns in form of (I) gradual bending of the lattice (high density of free dislocations), (II) highly-deformed margins revealing a combination of low- and high-angle boundaries and gradual bending of the lattice, and (III) a low-angle boundary (LAB) network. Chemical and isotopic maps and profiles show that trace elements in zircon are re-distributed in all plastically-deformed domains. Changes in trace element composition along LABs are sometimes revealed by brighter CL and darker BSE signal. LABs and domains of high free-dislocation density have depletion in U, Y, Yb and enrichment in Ce, La and Nd, while Ti and P are either enriched, depleted or remain unaffected, and Hf demonstrates stability. Y and Yb are decreased in concentration across LABs, and have oscillating concentration in domains of high free-dislocation density. Our observations confirm that crystal-plastically deformed domains in zircon act as effective pathways for trace cations.\nThe Pb isotopic system is disturbed by crystal-plastic deformation microstructures, as indicated by relative ^(207)Pb/^(206)Pb ages showing significant discordance in plastically-deformed zircon domains. In deformed domains, a positive correlation between dislocation density and the degree of isotopic age distortion is observed. Fractured or porous domains and domains with high density of (sub)grain boundaries are enriched in common Pb from the matrix, and thus show significantly older relative ^(207)Pb/^(206)Pb ages than pristine domains. In contrast, Pb loss occurs in domains with high free-dislocation density at a distance of 5\u201310 \u03bcm from the grain boundary, caused by out-diffusion of radiogenic Pb.\nThis study adds to a growing database on the consequences of crystal-plastic deformation for trace elements and isotopic systems in zircon. We provide additional evidence that such deformation cannot be neglected and may have important implications for zircon geochronology and geochemistry.", "doi": "10.1016/j.chemgeo.2016.12.030", "issn": "0009-2541", "publisher": "Elsevier", "publication": "Chemical Geology", "publication_date": "2017-02-05", "volume": "450", "pages": "183-198" }, { "id": "authors:xm2jn-c3g42", "collection": "authors", "collection_id": "xm2jn-c3g42", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170103-095536318", "type": "article", "title": "Olivine inclusions in Siberian diamonds and mantle xenoliths: Contrasting water and trace-element contents", "author": [ { "family_name": "Jean", "given_name": "M. M.", "clpid": "Jean-M-M" }, { "family_name": "Taylor", "given_name": "L. A.", "clpid": "Taylor-L-A" }, { "family_name": "Howarth", "given_name": "G. H.", "clpid": "Howarth-G-H" }, { "family_name": "Peslier", "given_name": "A. H.", "clpid": "Peslier-A-H" }, { "family_name": "Fedele", "given_name": "L.", "clpid": "Fedele-L" }, { "family_name": "Bodnar", "given_name": "R. J.", "clpid": "Bodnar-R-J" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Doucet", "given_name": "L. S.", "clpid": "Doucet-L-S" }, { "family_name": "Ionov", "given_name": "D. A.", "clpid": "Ionov-D-A" }, { "family_name": "Logvinova", "given_name": "A. M.", "clpid": "Logvinova-A-M" }, { "family_name": "Golovin", "given_name": "A. V.", "clpid": "Golovin-A-V" }, { "family_name": "Sobolev", "given_name": "N. V.", "clpid": "Sobolev-N-V" } ], "abstract": "A subject of continuing debate is how the Earth's lithospheric portion of the upper mantle has remained the thickest (> 200 km) and oldest (> 3 Gy) beneath cratons and is yet surrounded by a vigorously convecting asthenosphere. It is generally admitted that water is a key parameter in the strength and longevity of cratonic roots, because olivine, the main phase of the lithospheric mantle, becomes stronger if its water content decreases. Expanding upon the work presented in Novella et al. (2015) and Taylor et al. (2016), we report new water contents for additional olivine inclusions in diamonds together with the trace-element composition for all olivine inclusions, as well as for mantle xenoliths from various kimberlite pipes located on the Siberian craton. The olivine diamond inclusions from this study have systematically low-water contents (< 50 ppmw H_2O), moderate to high forsterite (e.g., Fo_(91\u201394)) contents and low Ni, Co, and Zn ppm contents (e.g., < 2848, < 108, and < 47 ppm, respectively). In contrast, olivines from Siberian craton mantle xenoliths have a wide range of water contents (6\u2013323 ppmw H_2O) and extend to lower-Fo (91\u201392), Ni, Co, and Zn-rich compositions, compared to the diamond inclusions. Depleted incompatible trace-element concentrations in olivine (0.1\u20130.001 \u00d7 Primitive Mantle) advance our hypothesis for the protogenetic origins for the majority of Siberian diamond inclusions. These observations are consistent with the peridotite xenoliths as representing a part of the cratonic lithosphere that has experienced melt re-fertilization, which has also transported water. The olivine diamond inclusions, on the other hand, preserve \"micro-samples\" of an initial, dry cratonic lithosphere, mostly resulting from melting events. These inclusions are likely sourced from the initial cratonic mantle lithosphere, which thereby, resisted delamination over time, due to its buoyancy and strength, imparted from melt and water depletion, respectively. And thus, our data provides a major argument that the kimberlite-hosted mantle xenoliths may be more metasomatized than common rocks at the base of the Siberian and other cratonic roots away from kimberlite fields.", "doi": "10.1016/j.lithos.2016.07.023", "issn": "0024-4937", "publisher": "Elsevier", "publication": "Lithos", "publication_date": "2016-11-15", "volume": "265", "pages": "31-41" }, { "id": "authors:gqbmx-p1c96", "collection": "authors", "collection_id": "gqbmx-p1c96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161117-095800100", "type": "article", "title": "Phosphate minerals in the H group of ordinary chondrites, and fluid activity recorded by apatite heterogeneity in the Zag H3-6 regolith breccia", "author": [ { "family_name": "Jones", "given_name": "Rhian H.", "clpid": "Jones-R-H" }, { "family_name": "McCubbin", "given_name": "Francis M.", "clpid": "McCubbin-F-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Phosphate minerals in ordinary chondrites provide a record of fluids that were present during metamorphic heating of the chondrite parent asteroids. We have carried out a petrographic study of the phosphate minerals, merrillite and apatite, in metamorphosed H group ordinary chondrites of petrologic type 4\u20136, to understand development of phosphate minerals and associated fluid evolution during metamorphism. In unbrecciated chondrites, apatite is Cl rich and shows textural evolution from fine-grained apatite-merrillite assemblages in type 4 toward larger, uniform grains in type 6. The Cl/F ratio in apatite shows a similar degree of heterogeneity in all petrologic types, and no systematic change in compositions with metamorphic grade, which suggests that compositions in each meteorite are dictated by localized conditions, possibly because of a limited fluid/rock ratio. The development of phosphate minerals in H chondrites is similar to that of L and LL chondrites, despite the fact that feldspar equilibration resulting from albitization is complete in H4 chondrites but not in L4 or LL4 chondrites. This suggests that albitization took place during an earlier period of the metamorphic history than that recorded by preserved apatite compositions, and chemical equilibrium was not achieved throughout the H chondrite parent body or bodies during the late stages of metamorphism. A relict igneous clast in the H5 chondrite, Oro Grande has apatite rims on relict phenocrysts of (possibly) diopside that have equilibrated with the host chondrite. Apatite in the Zag H3\u20136 regolith breccia records a complex fluid history, which is likely related to the presence of halite in this meteorite. The porous dark H4 matrix of Zag, where halite is observed, has a high apatite/merrillite ratio, and apatite is extremely Cl rich. One light H6 clast contains similarly Cl-rich apatite. In a second light H6 clast, apatite compositions are very heterogeneous and more F-rich. Apatites in both H4 matrix and H6 clasts have very low H_2O contents. Heterogeneous apatite compositions in Zag record multiple stages of regolith processing and shock at the surface of the H chondrite parent body, and apatite records either the passage of fluids of variable compositions resulting from different impact-related processes, or the passage of a single fluid whose composition evolved as it interacted with the chondrite regolith. Unraveling the history of apatite can potentially help to interpret the internal structure of chondrite parent bodies, with implications for physical and mechanical properties of chondritic asteroids. The behavior of halogens recorded by apatite is important for understanding the behavior of volatile elements in general: if impact-melt materials close to the surface of a chondritic asteroid are readily degassed, the volatile inventories of terrestrial planets could be considerably more depleted than the CI carbonaceous chondrite abundances that are commonly assumed.", "doi": "10.2138/am-2016-5728", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2016-11", "series_number": "11", "volume": "101", "issue": "11", "pages": "2452-2467" }, { "id": "authors:jw26r-ta835", "collection": "authors", "collection_id": "jw26r-ta835", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160725-160158868", "type": "article", "title": "Rare-earth-element minerals in martian breccia meteorites NWA 7034 and 7533: Implications for fluid\u2013rock interaction in the martian crust", "author": [ { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Beckett", "given_name": "John R.", "clpid": "Beckett-J-R" }, { "family_name": "Chen", "given_name": "Yang", "orcid": "0000-0002-8964-0084", "clpid": "Chen-Yang" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Paired martian breccia meteorites, Northwest Africa (NWA) 7034 and 7533, are the first martian rocks found to contain rare-earth-element (REE) phosphates and silicates. The most common occurrence is as clusters of anhedral monazite-(Ce) inclusions in apatite. Occasionally, zoned, irregular merrillite inclusions are also present in apatite. Monazite-bearing apatite is sometimes associated with alkali-feldspar and Fe-oxide. Apatite near merrillite and monazite generally contains more F and OH (F-rich region) than the main chlorapatite host and forms irregular boundaries with the main host. Locally, the composition of F-rich regions can reach pure fluorapatite. The chlorapatite hosts are similar in composition to isolated apatite without monazite inclusions, and to euhedral apatite in lithic clasts. The U\u2013Th-total Pb ages of monazite in three apatite are 1.0\u00b10.4Ga (2\u03c3), 1.1\u00b10.5Ga (2\u03c3), and 2.8\u00b10.7Ga (2\u03c3), confirming a martian origin. The texture and composition of monazite inclusions are mostly consistent with their formation by the dissolution of apatite and/or merrillite by fluid at elevated temperatures (>100\u2009\u00b0C).\nIn NWA 7034, we observed a monazite-chevkinite-perrierite-bearing benmoreite or trachyandesite clast. Anhedral monazite and chevkinite-perrierite grains occur in a matrix of sub-micrometer REE-phases and silicates inside the clast. Monazite-(Ce) and -(Nd) and chevkinite-perrierite-(Ce) and -(Nd) display unusual La and Ce depletion relative to Sm and Nd. In addition, one xenotime-(Y)-bearing pyrite-ilmenite-zircon clast with small amounts of feldspar and augite occurs in NWA 7034. One xenotime crystal was observed at the edge of an altered zircon grain, and a cluster of xenotime crystals resides in a mixture of alteration materials. Pyrite, ilmenite, and zircon in this clast are all highly altered, zircon being the most likely source of Y and HREE now present in xenotime. The association of xenotime with zircon, low U and Th contents, and the low Yb content relative to Gd and Dy in xenotime suggest the possible formation of xenotime as a byproduct of fluid\u2013zircon reactions.\nOn the basis of relatively fresh apatite grains and lithic clasts in the same samples, we propose that the fluid\u2013rock/mineral reactions occurred in the source rocks before their inclusion in NWA 7034 and 7533. Additionally, monazite-bearing apatite and REE-mineral-bearing clasts are possibly derived from different crustal origins. Thus, our results imply the wide-occurrence of hydrothermal fluids in the martian crust at 1 Ga or older, which were probably induced by impacts or large igneous intrusions.", "doi": "10.1016/j.epsl.2016.06.041", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2016-10-01", "volume": "451", "pages": "251-262" }, { "id": "authors:0d32w-81b44", "collection": "authors", "collection_id": "0d32w-81b44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160901-082436526", "type": "article", "title": "Petrogenesis of the Northwest Africa 4898 high-Al mare basalt", "author": [ { "family_name": "Li", "given_name": "Shaolin", "clpid": "Li-Shaolin" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Linyan", "clpid": "Wang-Linyan" }, { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" } ], "abstract": "Northwest Africa (NWA) 4898 is the only low-Ti, high-Al basaltic lunar meteorite yet recognized. It predominantly consists of pyroxene (53.8 vol%) and plagioclase (38.6 vol%). Pyroxene has a wide range of compositions (En_(12\u201362)Fs_(25\u201362)Wo_(11\u201336)), which display a continuous trend from Mg-rich cores toward Ca-rich mantles and then to Fe-rich rims. Plagioclase has relatively restricted compositions (An_(87\u201396)Or_(0\u20131)Ab_(4\u201313)), and was transformed to maskelynite. The REE zoning of all silicate minerals was not significantly modified by shock metamorphism and weathering. Relatively large (up to 1 mm) olivine phenocrysts have homogenous inner parts with Fo ~74 and sharply decrease to 64 within the thin out rims (~30 \u03bcm in width). Four types of inclusions with a variety of textures and modal mineralogy were identified in olivine phenocrysts. The contrasting morphologies of these inclusions and the chemical zoning of olivine phenocrysts suggest NWA 4898 underwent at least two stages of crystallization. The aluminous chromite in NWA 4898 reveals that its high alumina character was inherited from the parental magma, rather than by fractional crystallization. The mineral chemistry and major element compositions of NWA 4898 are different from those of 12038 and Luna 16 basalts, but resemble those of Apollo 14 high-Al basalts. However, the trace element compositions demonstrate that NWA 4898 and Apollo 14 high-Al basalts could not have been derived from the same mantle source. REE compositions of its parental magma indicate that NWA 4898 probably originated from a unique depleted mantle source that has not been sampled yet. Unlike Apollo 14 high-Al basalts, which assimilated KREEPy materials during their formation, NWA 4898 could have formed by closed-system fractional crystallization.", "doi": "10.1111/maps.12663", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2016-07", "series_number": "7", "volume": "51", "issue": "7", "pages": "1268-1288" }, { "id": "authors:c0m8j-e1630", "collection": "authors", "collection_id": "c0m8j-e1630", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160708-101905095", "type": "article", "title": "D-poor hydrogen in lunar mare basalts assimilated from lunar regolith", "author": [ { "family_name": "Treiman", "given_name": "Allan H.", "orcid": "0000-0002-8073-2839", "clpid": "Treiman-A-H" }, { "family_name": "Boyce", "given_name": "Jeremy W.", "clpid": "Boyce-J-W" }, { "family_name": "Greenwood", "given_name": "James P.", "clpid": "Greenwood-J-P" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Gross", "given_name": "Juliane", "clpid": "Gross-J" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Stolper", "given_name": "Edward M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "Apatite grains in lunar mare basalts contain hydrogen that ranges in D/H ratio by more than a factor of two. For most of these basalts, the D/H ratios in their apatite grains decrease with measures of the host basalts' time spent at elevated temperature, specifically the Fe-Mg homogenization of their pyroxenes. Most basalts with homogeneous pyroxenes (i.e., with constant Fe/Mg ratio) have apatite grains with low D/H (\u03b4D \u2248 \u2212100\u2030), whereas most basalts with heterogeneous pyroxenes (i.e., varying or zoned Fe/Mg) have apatite with high D/H (\u03b4D up to ~ +1100\u2030). This relationship suggests that low D/H values were acquired during thermal processing, i.e., during Fe-Mg chemical equilibration, during or after emplacement. This light hydrogen is likely derived from solar wind implanted into the lunar regolith (with \u03b4D from \u2212125\u2030 to \u2212800\u2030), and could enter basalts either by assimilation of regolith or by vapor transport from regolith heated by the flow. If a basalt could not interact with regolith rich in solar wind (e.g., it was emplaced onto other fresh basalts), its apatite could retain a magmatic D/H signature. The high D/H component (in the apatites of unequilibrated basalts) is most reasonably that indigenous magmatic hydrogen, i.e., representing hydrogen in the basalt's source mantles, or magmatic hydrogen that was residual after partial degassing of H_2.", "doi": "10.2138/am-2016-5582", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2016-07", "series_number": "7", "volume": "101", "issue": "7", "pages": "1596-1603" }, { "id": "authors:ybvyf-85013", "collection": "authors", "collection_id": "ybvyf-85013", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160218-110004369", "type": "article", "title": "Episodic carbonate precipitation in the CM chondrite ALH 84049: An ion microprobe analysis of O and C isotopes", "author": [ { "family_name": "Tyra", "given_name": "Mark", "clpid": "Tyra-M" }, { "family_name": "Brearley", "given_name": "Adrian", "clpid": "Brearley-A" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "We have determined the O and C isotope compositions of dolomite grains and the C isotope compositions of calcite grains in the highly altered CM1 chondrite, ALH 84049, using Secondary Ion Mass Spectrometry (SIMS). Chemically-zoned dolomite constitutes 0.8 volume percent (vol%) of the sample and calcite 0.9 vol%. Thirteen separate dolomite grains have \u03b413C values that range from 37 to 60 (\u00b12) \u2030, \u03b4^(18)O values from 25 to 32 (\u00b13) \u2030, and \u03b4^(17)O values from 10 to 16 (\u00b13) \u2030 (VSMOW). Intragrain \u03b4^(13)C values in dolomite vary up to 10\u2030. The \u03b4^(13)C values of three calcite grains are distinct from those of dolomite and range from 10 to 13 (\u00b12) \u2030 (PDB). Calcite and dolomite appear to record different precipitation episodes. Carbon isotope values of both dolomite and calcite in this single sample encompass much of the reported range for CM chondrites; our results imply that bulk carbonate C and O isotope analyses may oversimplify the history of carbonate precipitation. Multiple generations of carbonates with variable isotope compositions exist in ALH 84049 and, perhaps, in many CM chondrites. This work shows that one should exercise caution when using a clumped isotope approach to determine the original temperature and the isotopic compositions of water for CM chondrite carbonates. Less altered CM meteorites with more-homogeneous C isotope compositions, however, may be suitable for bulk-carbonate analyses, but detailed carbonate petrologic and isotopic characterization of individual samples is advised.", "doi": "10.1016/j.gca.2015.10.034", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2016-02-15", "volume": "175", "pages": "195-207" }, { "id": "authors:eymyv-sb409", "collection": "authors", "collection_id": "eymyv-sb409", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170711-075450501", "type": "article", "title": "Low water contents in diamond mineral inclusions: Proto-genetic origin in a dry cratonic lithosphere", "author": [ { "family_name": "Taylor", "given_name": "Lawrence A.", "clpid": "Taylor-L-A" }, { "family_name": "Logvinova", "given_name": "Alla M.", "clpid": "Logvinova-A-M" }, { "family_name": "Howarth", "given_name": "Geoffrey H.", "clpid": "Howarth-G-H" }, { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Peslier", "given_name": "Anne H.", "clpid": "Peslier-A-H" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Chen", "given_name": "Yang", "clpid": "Chen-Yang-JPL" }, { "family_name": "Sobolev", "given_name": "Nikolay V.", "clpid": "Sobolev-N-V" } ], "abstract": "The mantle is the major reservoir of Earth's water, hosted within Nominally Anhydrous Minerals (NAMs) (e.g., Bell and Rossman, 1992; Peslier et al., 2010; Peslier, 2010; Nestola and Smyth, 2015), in the form of hydrogen bonded to the silicate's structural oxygen. From whence cometh this water? Is the water in these minerals representative of the Earth's primitive upper mantle or did it come from melting events linked to crustal formation or to more recent metasomatic/re-fertilization events? During diamond formation, NAMs are encapsulated at hundreds of kilometers depth within the mantle, thereby possibly shielding and preserving their pristine water contents from re-equilibrating with fluids and melts percolating through the lithospheric mantle. Here we show that the NAMs included in diamonds from six locales on the Siberian Craton contain measurable and variable H_2O concentrations from 2 to 34 parts per million by weight (ppmw) in olivine, 7 to 276 ppmw in clinopyroxene, and 11\u201317 ppmw in garnets. Our results suggest that if the inclusions were in equilibrium with the diamond-forming fluid, the water fugacity would have been unrealistically low. Instead, we consider the H_2O contents of the inclusions, shielded by diamonds, as pristine representatives of the residual mantle prior to encapsulation, and indicative of a protogenetic origin for the inclusions. Hydrogen diffusion in the diamond does not appear to have modified these values significantly. The H_2O contents of NAMs in mantle xenoliths may represent some later metasomatic event(s), and are not always representative of most of the continental lithospheric mantle. Results from the present study also support the conclusions of Peslier et al. (2010) and Novella et al. (2015) that the dry nature of the SCLM of a craton may provide stabilization of its thickened continental roots.", "doi": "10.1016/j.epsl.2015.10.042", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2016-01-01", "volume": "433", "pages": "125-132" }, { "id": "authors:9zp1q-axz05", "collection": "authors", "collection_id": "9zp1q-axz05", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160204-105344624", "type": "article", "title": "Petrography and geochemistry of the enriched basaltic shergottite Northwest Africa 2975", "author": [ { "family_name": "He", "given_name": "Qi", "clpid": "He-Qi" }, { "family_name": "Xiao", "given_name": "Long", "clpid": "Xiao-Long" }, { "family_name": "Balta", "given_name": "J. Brian", "clpid": "Balta-J-B" }, { "family_name": "Baziotis", "given_name": "Ioannis P.", "clpid": "Baziotis-I-P" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "We present a study of the petrology and geochemistry of basaltic shergottite Northwest Africa 2975 (NWA 2975). NWA 2975 is a medium-grained basalt with subophitic to granular texture. Electron microprobe (EMP) analyses show two distinct pyroxene compositional trends and patchy compositional zoning patterns distinct from those observed in other meteorites such as Shergotty or QUE 94201. As no bulk sample was available to us for whole rock measurements, we characterized the fusion crust and its variability by secondary ion mass spectrometer (SIMS) measurements and laser ablation inductively coupled plasma spectroscopy (LA-ICP-MS) analyses as a best-available proxy for the bulk rock composition. The fusion crust major element composition is comparable to the bulk composition of other enriched basaltic shergottites, placing NWA 2975 within that sample group. The CI-normalized REE (rare earth element) patterns are flat and also parallel to those of other enriched basaltic shergottites. Merrillite is the major REE carrier and has a flat REE pattern with slight depletion of Eu, parallel to REE patterns of merrillites from other basaltic shergottites. The oxidation state of NWA 2975 calculated from Fe-Ti oxide pairs is NNO-1.86, close to the QFM buffer. NWA 2975 represents a sample from the oxidized and enriched shergottite group, and our measurements and constraints on its origin are consistent with the hypothesis of two distinct Martian mantle reservoirs: a reduced, LREE-depleted reservoir and an oxidized, LREE-enriched reservoir. Stishovite, possibly seifertite, and dense SiO_2 glass were also identified in the meteorite, allowing us to infer that NWA 2975 experienced a realistic shock pressure of ~30 GPa.", "doi": "10.1111/maps.12571", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-12", "series_number": "12", "volume": "50", "issue": "12", "pages": "2024-2044" }, { "id": "authors:rtm76-3m302", "collection": "authors", "collection_id": "rtm76-3m302", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151217-080518907", "type": "article", "title": "Ankerite grains with dolomite cores: A diffusion chronometer for low- to medium-grade regionally metamorphosed clastic sediments", "author": [ { "family_name": "Ferry", "given_name": "John M.", "clpid": "Ferry-J-M" }, { "family_name": "Stubbs", "given_name": "Joanne E.", "clpid": "Stubbs-J-E" }, { "family_name": "Xu", "given_name": "Huifang", "orcid": "0000-0002-7464-0057", "clpid": "Xu-Huifang" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" } ], "abstract": "Ankerite grains with dolomite cores occur in marls, pelites, and psammites from a Buchan terrain in Maine and a Barrovian terrain in Vermont (U.S.A.). Dolomite cores are typically \u226420 \u03bcm in diameter, have sharp but irregular contacts with ankerite, and have the same crystallographic orientation as ankerite rims. Ankerite grains with dolomite cores are common in the chlorite zone, less abundant in the biotite and garnet zones, and rare (Vermont) or absent (Maine) at higher grades. The texture and crystallographic orientation of dolomite and ankerite and the sharpness of the dolomite-ankerite contact are consistent with partial replacement of detrital dolomite by ankerite by solution-reprecipitation. Metamorphic biotite is in Fe-Mg exchange equilibrium with ankerite rims but not with dolomite cores, implying that ankerite did not form long after biotite (biotite has no phlogopite cores). Possible sources of iron for the formation of ankerite are reduction of ferric iron hydroxide or the smectite-to-illite reaction during diagenesis. \nThe sharpness of the dolomite-ankerite contact is a diffusion chronometer that constrains timescales of metamorphic process. Relatively low spatial resolution analyses of Fe/Mg across the contact with a NanoSIMS instrument and a FEG TEM give upper bounds on the thickness of the transition from ankerite to dolomite of ~2 and ~0.5 \u03bcm, respectively. Higher resolution analysis of BSE grayscale contrast with a FEG SEM gives a thickness ~100 nm. Fit of the grayscale profile to a model of one-dimensional diffusion across an infinite plane gives Dt = 10^(\u221215) m^2 (\u00b1 a factor of 5), where D is the effective Fe-Mg interdiffusion coefficient and t is the duration of diffusion. Using the published experimental determination of D, upper bounds on the residence time of ankerite grains with dolomite cores at peak T = 400\u2013500 \u00b0C, on the duration of linear cooling from peak T to 100 \u00b0C, and on the duration of linear heating from 100 \u00b0C to peak T followed by linear cooling to 100 \u00b0C are all <1 yr. For linear heating and cooling lasting 10^6 years, peak T could not have been >100 \u00b0C. \nThe question is what explains the occurrence of ultrasteep composition gradients between dolomite and ankerite. Regional metamorphism on a timescale of a year or less is unrealistic. No barrier to diffusion at the dolomite-ankerite contact was observed in TEM images. Post-metamorphic formation of ankerite at very low temperature is ruled out by Fe-Mg exchange equilibrium between biotite and ankerite but not dolomite. It is unlikely that the steep composition gradients were preserved by intracrystalline pressure gradients. \nAlternatively, the steep composition gradients would be consistent with timescales of metamorphic process ~10^6 years or longer if D values during metamorphism were approximately six orders of magnitude or more smaller than those measured in the laboratory. The error of measurement is much less, approximately \u00b1 a factor of 2. A correction to D for the difference in P between measurements (0.1 MPa) and metamorphism (350\u2013800 MPa) is likely an order of magnitude or less. Oxygen activity (a_(O2)), however, was 17\u201320 orders of magnitude larger during the laboratory measurements than during metamorphism. A correction to measured D for the difference in a_(O2_ between experiment and metamorphism appears to be the likeliest way to reconcile the steep composition gradients with realistic timescales of metamorphism. Before ankerite grains with dolomite cores are fully realized as a useful diffusion chronometer for low- and medium-grade metamorphic rocks, the rates of Fe-Mg interdiffusion in ankerite and dolomite need to be calibrated as a function of a_(O2).", "doi": "10.2138/am-2015-5209", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2015-11", "series_number": "11-12", "volume": "100", "issue": "11-12", "pages": "2443-2457" }, { "id": "authors:h76ce-m3j64", "collection": "authors", "collection_id": "h76ce-m3j64", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150904-065222469", "type": "article", "title": "Water, fluorine, and sulfur concentrations in the lunar mantle", "author": [ { "family_name": "Chen", "given_name": "Yang", "clpid": "Chen-Yang-JPL" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John", "clpid": "Eiler-J-M" }, { "family_name": "Stolper", "given_name": "Edward M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "The concentrations of volatile elements in the moon have important implications for the formation of the earth\u2013moon system. There is currently a debate regarding the water content of the lunar mantle: Authors studying H_2O in lunar pyroclastic glass beads and in olivine-hosted melt inclusions in such pyroclastic samples and in plagioclase crystals in lunar highland anorthosites infer hundreds of ppm H_2O in the lunar mantle. In contrast, authors studying Zn/Fe ratios infer that the H_2O concentration in the lunar mantle is \u22641 ppm, and they argue that the glassy lunar basalts are a local anomaly. We contribute to a resolution of the debate by a broader examination of the concentrations of H_2O and other volatile components in olivine-hosted melt inclusions in a wider range of lunar mare basalts, including crystalline melt inclusions that are homogenized by melting in the laboratory. We find that F, Cl, and S concentrations in various lunar melt inclusions (including those in glassy lunar basalts) are similar to one another, and previously studied glassy lunar basalts are not a local anomaly in terms of these volatile concentrations. Furthermore, we estimate the pre-degassing H_2O/Ce, F/Nd, and S/Dy ratios of mare basaltic magmas to be at least 64, 4.0 and 100 respectively. These ratios are lower than those of primitive earth mantle by a factor of 3, 5, and 4 respectively. The depletion factors of these volatile elements relative to the earth's primitive mantle do not correlate strongly with volatility or bonding energy, and indeed they are roughly constant and similar to those of other volatile elements such as Li, Cs, Rb and K. This approximate constancy of volatile depletion in the moon relative to the earth can be explained by assuming that both the earth and the moon acquired volatiles from a similar source or by a similar mechanism but the earth was more efficient in acquiring the volatiles. We estimate the H_2O, F and S concentrations in the primitive lunar mantle source to be at least 110, 5.3, and 70 ppm, respectively \u2013 similar to or slightly lower than those in terrestrial MORB mantle.", "doi": "10.1016/j.epsl.2015.06.046", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2015-10-01", "volume": "427", "pages": "37-46" }, { "id": "authors:tw2r8-6fj95", "collection": "authors", "collection_id": "tw2r8-6fj95", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151027-143619926", "type": "article", "title": "In situ SIMS oxygen isotope analyses: Evidence for the formation of aluminum-rich chondrules from ordinary chondrites", "author": [ { "family_name": "Jiang", "given_name": "Yun", "clpid": "Jiang-Yun" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" } ], "abstract": "Aluminum-rich chondrules (ARCs), which share mineralogic and chemical properties with both Ca, Al-rich inclusions (CAIs) and ferromagnesian chondrules, play an important role in revealing their temporal and petrogenetic relationships. In this work, seven ARCs were found in three ordinary chondrites GRV 022410 (H4), GRV 052722 (H3.7) and Julesburg (L3.6). They contain bulk Al_2O_3 \u223c 17%\u201333% and exhibit igneous textures composed of olivine, high- and low-Ca pyroxene, plagioclase, spinel and glass. In situ SIMS analyses show that ARCs have oxygen isotopic compositions (\u03b4^(18)O=\u22126.1\u2030\u20137.1\u2030; \u03b4^(17)O= \u22124.5\u2030\u20135.1\u2030) close to ferromagnesian chondrules but far more depleted in ^(16)O than CAIs (\u03b4^(18)O=\u221240\u2030; \u03b4^(17)O=\u221240\u2030). Most ARCs plot close to the terrestrial mass fractionation (TF) line, and a few between the TF and carbonaceous chondrite anhydrous mixing (CCAM) lines. Plagioclase, nepheline and glass suffered O-isotopic exchanges during the metamorphism processes in the parent body. Spinel, olivine and pyroxene represent the primary O-isotopic compositions of ARCs, and define a fitted line with a slope of \u223c 0.7\u00b10.1. Compared with the results of previous studies, shallower slope as well as more depleted ^(16)O compositions further demonstrates that ARCs in ordinary chondrites are not a simple mixing product of ferromagnesian chondrules and CAIs. Instead, they probably experienced higher-degree oxygen isotope exchange with a ^(16)O-poor nebular gas reservoir during multiple melting episodes.", "doi": "10.1007/s11430-015-5105-7", "issn": "1674-7313", "publisher": "Springer", "publication": "Science China Earth Sciences", "publication_date": "2015-10", "series_number": "10", "volume": "58", "issue": "10", "pages": "1748-1757" }, { "id": "authors:gbybg-4vy60", "collection": "authors", "collection_id": "gbybg-4vy60", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150609-134752972", "type": "article", "title": "Evidence in Tissint for recent subsurface water on Mars", "author": [ { "family_name": "Chen", "given_name": "Yang", "clpid": "Chen-Yang-JPL" }, { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Taylor", "given_name": "Lawrence A.", "clpid": "Taylor-L-A" } ], "abstract": "We report unambiguous chemical evidence for subsurface water activity in the martian crust at <600 Ma based on the data from Tissint, a fresh martian meteorite fall with minimal terrestrial weathering. The impact-melt pockets in Tissint contain abundant volatiles (H_2O, CO_2, F, and Cl), and their concentrations are positively correlated with each other. Higher H_2O concentrations also accompany higher deuterium contents. These correlations suggest mixing between two volatile sources. The first source is H_2O in the precursor basalt inherited from martian magma. Magmatic H_2O in the basalt had low deuterium concentration and was likely stored in the nominally anhydrous minerals. This source contributed little CO_2 or halogens to the impact melts. The second source is inferred to be aqueous-alteration products introduced to the basalt by water activity after the basalt erupted. These alteration materials contributed more volatiles to the impact melts than the magmatic source, and had high deuterium abundance, reflecting isotope equilibrium with recent martian atmosphere. The water activities occurred beneath the martian surface after \u223c600 Ma (crystallization age), but before \u223c1 Ma (ejection age). The chemical and isotopic signatures of the alteration products in Tissint resemble previously known martian samples associated with old water activities on Mars, which can be traced back to \u223c4.2 billion years ago (e.g., the mudstone at Gale Crater). This similarity in chemistry and the wide age-span indicate that such water activities were common on Mars throughout its history, which had the potential to form habitable environment. However, the rarity of the volatile-rich zone in Tissint suggests that Martian crustal aqueous processes, where they have occurred are generally limited in their extent of water\u2013rock reaction.", "doi": "10.1016/j.epsl.2015.05.004", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2015-09-01", "volume": "425", "pages": "55-63" }, { "id": "authors:f33zy-4ta45", "collection": "authors", "collection_id": "f33zy-4ta45", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151221-083226607", "type": "article", "title": "The chlorine isotope fingerprint of the lunar magma ocean", "author": [ { "family_name": "Boyce", "given_name": "Jeremy W.", "orcid": "0000-0003-0648-2533", "clpid": "Boyce-Jeremy-W" }, { "family_name": "Treiman", "given_name": "Allan H.", "orcid": "0000-0002-8073-2839", "clpid": "Treiman-Allan-H" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Eiler", "given_name": "John M.", "orcid": "0000-0001-5768-7593", "clpid": "Eiler-J-M" }, { "family_name": "Gross", "given_name": "Juliane", "orcid": "0000-0002-5288-0981", "clpid": "Gross-Juliane" }, { "family_name": "Greenwood", "given_name": "James P.", "orcid": "0000-0001-7884-2740", "clpid": "Greenwood-James-P" }, { "family_name": "Stolper", "given_name": "Edward M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "The Moon contains chlorine that is isotopically unlike that of any other body yet studied in the Solar System, an observation that has been interpreted to support traditional models of the formation of a nominally hydrogen-free (\"dry\") Moon. We have analyzed abundances and isotopic compositions of Cl and H in lunar mare basalts, and find little evidence that anhydrous lava outgassing was important in generating chlorine isotope anomalies, because ^(37)Cl/^(35)Cl ratios are not related to Cl abundance, H abundance, or D/H ratios in a manner consistent with the lava-outgassing hypothesis. Instead, ^(37)Cl/^(35)Cl correlates positively with Cl abundance in apatite, as well as with whole-rock Th abundances and La/Lu ratios, suggesting that the high ^(37)Cl/^(35)Cl in lunar basalts is inherited from urKREEP, the last dregs of the lunar magma ocean. These new data suggest that the high chlorine isotope ratios of lunar basalts result not from the degassing of their lavas but from degassing of the lunar magma ocean early in the Moon's history. Chlorine isotope variability is therefore an indicator of planetary magma ocean degassing, an important stage in the formation of terrestrial planets.", "doi": "10.1126/sciadv.1500380", "pmcid": "PMC4643783", "issn": "2375-2548", "publisher": "American Association for the Advancement of Science", "publication": "Science Advances", "publication_date": "2015-09", "series_number": "8", "volume": "1", "issue": "8", "pages": "Art. No. e1500380" }, { "id": "authors:k6ttg-wep72", "collection": "authors", "collection_id": "k6ttg-wep72", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141111-093651164", "type": "article", "title": "Ion Implants as Matrix-Appropriate Calibrators for Geochemical Ion Probe Analyses", "author": [ { "family_name": "Burnett", "given_name": "Donald S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Jurewicz", "given_name": "Amy J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-A-J-G" }, { "family_name": "Woolum", "given_name": "Dorothy S.", "clpid": "Woolum-D-S" }, { "family_name": "Wang", "given_name": "Jianhua", "orcid": "0000-0002-7671-2413", "clpid": "Wang-Jianhua" }, { "family_name": "Paque", "given_name": "Julie M.", "orcid": "0000-0003-0554-7876", "clpid": "Paque-J-M" }, { "family_name": "Nittler", "given_name": "Larry R.", "orcid": "0000-0002-5292-6089", "clpid": "Nittler-L-R" }, { "family_name": "McKeegan", "given_name": "Kevin D.", "clpid": "McKeegan-K-D" }, { "family_name": "Humayun", "given_name": "Munir", "orcid": "0000-0002-5830-5208", "clpid": "Humayun-M-S" }, { "family_name": "Hervig", "given_name": "Richard", "clpid": "Hervig-R-L" }, { "family_name": "Heber", "given_name": "Veronika S.", "clpid": "Heber-V-S" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Ion microprobe elemental and isotopic determinations can be precise but difficult to quantify. Error is introduced when the reference material and the sample to be analysed have different compositions. Mitigation of such \"matrix effects\" is possible using ion implants. If a compositionally homogeneous reference material is available which is \"matrix-appropriate,\" i.e., close in major element composition to the sample to be analysed, but having an unknown concentration of the element, E, to be determined, ion implantation can be used to introduce a known amount of an E isotope, calibrating the E concentration and producing a matrix-appropriate calibrator. Nominal implant fluences (ions cm^(\u22122)) are inaccurate by amounts up to approximately 30%. However, ion implantation gives uniform fluences over large areas, thus it is possible to \"co-implant\" an additional reference material of any bulk composition having known amounts of E, independently calibrating the implant fluence. Isotope-ratio measurement standards can be produced by implanting two different isotopes, but permil level precision requires post-implant calibration of the implant isotopic ratio. Examples discussed include: (1) standardising Li in melilite; (2) calibrating a ^(25)Mg implant fluence using NIST SRM 617 glass; and (3) using Si co-implanted with ^(25)Mg alongside NIST SRM 617 to produce a calibrated measurement of Mg in Si.", "doi": "10.1111/j.1751-908X.2014.00318.x", "issn": "1639-4488", "publisher": "Wiley", "publication": "Geostandards and Geoanalytical Research", "publication_date": "2015-09", "series_number": "3", "volume": "39", "issue": "3", "pages": "265-276" }, { "id": "authors:0smq8-fmr32", "collection": "authors", "collection_id": "0smq8-fmr32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150831-083659279", "type": "article", "title": "SIMS Analysis of OH and D/H of Apatites from Eucrites", "author": [ { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" } ], "abstract": "Eucrites, a member of the howardite-eucritediogenite\n(HED) group, are basaltic meteorites that are believed\nto come from the asteroid Vesta [e.g., 1]. A recent study of water\nconcentration and hydrogen isotope of eucrite apatite [2] suggested\nan early accretion of water from a carbonaceous chondrite\u2013\nlike source on\nEarth, Vesta and other planetary bodies\nin the inner\nsolar system.\nIn this study, we present results of OH and D/H\nanalyses of apatites from more eucrite samples.", "doi": "10.1111/maps.12501", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-08", "series_number": "S1", "volume": "50", "issue": "S1", "pages": "Art. No. 5376" }, { "id": "authors:w99ys-rf711", "collection": "authors", "collection_id": "w99ys-rf711", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150828-153509694", "type": "article", "title": "New Rock Types from Mars: Trace Element Signatures in NWA 7034 Clasts", "author": [ { "family_name": "Chen", "given_name": "Y.", "clpid": "Chen-Yang-JPL" }, { "family_name": "Liu", "given_name": "Y.", "clpid": "Liu-Yang-JPL" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" } ], "abstract": "NWA 7034 contains new types of igneous rocks from Mars that were not represented by the SNC meteorites [1, 2, 3]. The new types may provide more information on magmatism on Mars. Here we investigate rare-earth element concentrations in common minerals in lithic clasts in NWA 7034 in order to further assess the characteris-tics of the magmatic sources.", "doi": "10.1111/maps.12501", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-08", "series_number": "S1", "volume": "50", "issue": "S1", "pages": "Art. No. 5239" }, { "id": "authors:skv1n-pzs10", "collection": "authors", "collection_id": "skv1n-pzs10", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150828-125414390", "type": "article", "title": "Exploring the Moon's surface for remnants of the lunar mantle 1. Dunite xenoliths in mare basalts. A crustal or mantle origin?", "author": [ { "family_name": "Shearer", "given_name": "Charles K.", "clpid": "Shearer-C-K" }, { "family_name": "Burger", "given_name": "Paul V.", "clpid": "Burger-P-V" }, { "family_name": "Bell", "given_name": "Aaron S.", "clpid": "Bell-A-S" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Neal", "given_name": "Clive R.", "clpid": "Neal-C-R" } ], "abstract": "Remotely sensed observations from recent missions (e.g., GRAIL, Kaguya, Chandrayaan-1) have been interpreted as indicating that the deep crust and upper mantle are close to or at the lunar surface in many large impact basins (e.g., Crisium, Apollo, Moscoviense). If this is correct, the capability of either impact or volcanic processes to transport mantle lithologies to the lunar surface should be enhanced in these regions. Somewhat problematic to these observations and interpretations is that examples of mantle lithologies in the lunar sample collection (Apollo Program, Luna Program, lunar meteorites) are at best ambiguous. Dunite xenoliths in high-Ti mare basalt 74275 are one of these ambiguous examples. In this high-Ti mare basalt, olivine occurs in three generations: olivine associated with dunite xenoliths, olivine megacrysts, and olivine microphenocrysts. The dunite xenoliths are anhedral in shape and are generally greater than 800 \u03bcm in diameter. The interior of the xenoliths are fairly homogeneous with regard to many divalent cations. For example, the Mg# (Mg/Mg + Fe \u00d7 100) ranges from 82 to 83 in their interiors and decreases from 82 to 68 over the 10\u201330 \u03bcm wide outer rim. Titanium and phosphorus X-ray maps of the xenolith illustrate that these slow diffusing elements preserve primary cumulate zoning textures. These textures indicate that the xenoliths consist of many individual olivine grains approximately 150\u2013200 \u03bcm in diameter with low Ti, Al, and P cores. These highly incompatible elements are enriched in the outer Fe-rich rims of the xenoliths and slightly enriched in the rims of the individual olivine grains. Highly compatible elements in olivine such as Ni exhibit a decrease in the rim surrounding the xenolith, an increase in the incompatible element depleted cores of the individual olivine grains, and a slight decrease in the \"interior rims\" of the individual olivine grains. Inferred melt composition, liquid lines of descent, and zoning profiles enable the reconstruction of the petrogenesis of the dunite xenoliths. Preservation of primary magmatic zoning (Ti, P, Al) and lack of textures similar to high-pressure mineral assemblages exhibited by the Mg-suite (Shearer et al. 2015) indicate that these xenoliths do not represent deep crustal or shallow mantle lithologies. Further, they are chemically and mineralogically distinct from Mg-suite dunites identified from the Apollo 17 site. More likely, they represent olivine cumulates that crystallized from a low-Ti mare basalt at intermediate to shallow crustal levels. The parent basalt to the dunite xenolith lithology was more primitive than low-Ti basalts thus far returned from the Moon. Furthermore, this parental magma and its more evolved daughter magmas are not represented in the basalt sample suite returned from the Taurus-Littrow Valley by the Apollo 17 mission. The dunite xenolith records several episodes of crystallization and re-equilibration. During the last episode of re-equilibration, the dunite cumulate was sampled by the 74275 high-Ti basalt and transported over a period of 30\u201370 days to the lunar surface.", "doi": "10.1111/maps.12480", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-08", "series_number": "8", "volume": "50", "issue": "8", "pages": "1449-1467" }, { "id": "authors:hjwmf-4j223", "collection": "authors", "collection_id": "hjwmf-4j223", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150831-083402769", "type": "article", "title": "Rare-Earth Minerals in Martian Meteorite NWA 7034/7533: Evidence for Fluid-Rock Interaction in the Martian Crust", "author": [ { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Ma", "given_name": "Chi", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Chen", "given_name": "Yang", "clpid": "Chen-Yang-JPL" }, { "family_name": "Beckett", "given_name": "John", "clpid": "Beckett-J-R" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Monazite, chevkinite-perrierite and xenotime\nare common rare-earth minerals in terrestrial rocks and important\nrepositories for the rare-earth-elements (REE). Liu and Ma [1-2]\nreported finding monazite, chevkinite-perrierite and xenotime in\nNWA 7034/7533, the 'Black Beauty' meteorite. Here, we provide\na more detailed textural and compositional analysis of these\nminerals; our results suggest an origin via fluid-rock interaction.", "doi": "10.1111/maps.12501", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-08", "series_number": "S1", "volume": "50", "issue": "S1", "pages": "Art. No. 5051" }, { "id": "authors:g4gt9-7ht22", "collection": "authors", "collection_id": "g4gt9-7ht22", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150828-111222397", "type": "article", "title": "Materials Older Than Ca-Al-Rich Inclusions", "author": [ { "family_name": "Paque", "given_name": "J. M.", "orcid": "0000-0003-0554-7876", "clpid": "Paque-J-M" }, { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Beckett", "given_name": "J. R.", "clpid": "Beckett-J-R" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Concentrations of refractory lithophile elements (RLEs) in Type B1 Ca-Al-rich inclusions (CAIs) are dominated by submicron inclusions, which are potentially relict grains older than the host CAI. These objects are so common, albeit tiny, that it is often very difficult to find a \"pure\" melilite.", "doi": "10.1111/maps.12501", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-08", "series_number": "S1", "volume": "50", "issue": "S1", "pages": "Art. No. 5281" }, { "id": "authors:fx716-3as41", "collection": "authors", "collection_id": "fx716-3as41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150828-160026376", "type": "article", "title": "Trace Element Chemistry of Larkman Nunatuk (LAR) 12011, a New Olivine-Phyric Shergottite", "author": [ { "family_name": "Caseres", "given_name": "J. R.", "clpid": "Caseres-J-R" }, { "family_name": "Liu", "given_name": "Y.", "clpid": "Liu-Yang-JPL" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Chen", "given_name": "Y.", "clpid": "Chen-Yang-JPL" }, { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Howarth", "given_name": "G.", "clpid": "Howarth-G-H" }, { "family_name": "Taylor", "given_name": "L. A.", "clpid": "Taylor-L-A" } ], "abstract": "The olivine-phyric shergottite LAR12011 was\nfound at Larkman Nunatuk during the 2012 ANSMET expedition\n[1]. The preliminary analysis of LAR12011 presented in [1] and\noxygen isotope analysis in [2] confirms its Martian origin. This\nnew sample is paired with LAR06319 [1-3]. Here, we present\npetrography and new data on the trace element chemistry of\nLAR12011.", "doi": "10.1111/maps.12501", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2015-08", "series_number": "S1", "volume": "50", "issue": "S1", "pages": "Art. No. 5357" }, { "id": "authors:7v4s2-d5h36", "collection": "authors", "collection_id": "7v4s2-d5h36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150220-131055817", "type": "article", "title": "Heavy water and \u00b9\u2075N labeling with NanoSIMS analysis reveals growth-rate dependent metabolic heterogeneity in chemostats", "author": [ { "family_name": "Kopf", "given_name": "Sebastian H.", "orcid": "0000-0002-2044-0201", "clpid": "Kopf-S-H" }, { "family_name": "McGlynn", "given_name": "Shawn E.", "orcid": "0000-0002-8199-7011", "clpid": "McGlynn-S-E" }, { "family_name": "Green-Saxena", "given_name": "Abigail", "orcid": "0000-0002-8502-6589", "clpid": "Saxena-A-G" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Newman", "given_name": "Dianne K.", "orcid": "0000-0003-1647-1918", "clpid": "Newman-D-K" }, { "family_name": "Orphan", "given_name": "Victoria J.", "orcid": "0000-0002-5374-6178", "clpid": "Orphan-V-J" } ], "abstract": "To measure single cell microbial activity and substrate utilization patterns in environmental systems, we employ a new technique using stable isotope labeling of microbial populations with heavy water (a passive tracer) and \u00b9\u2075N ammonium in combination with multi-isotope imaging mass spectrometry. We demonstrate simultaneous NanoSIMS analysis of hydrogen, carbon and nitrogen at high spatial and mass resolution, and report calibration data linking single cell isotopic compositions to the corresponding bulk isotopic equivalents for Pseudomonas aeruginosa and Staphylococcus aureus. Our results show that heavy water is capable of quantifying in situ single cell microbial activities ranging from generational time scales of minutes to years, with only light isotopic incorporation (~0.1 atom % \u00b2H). Applying this approach to study the rates of fatty acid biosynthesis by single cells of S. aureus growing at different rates in chemostat culture (~6 hours, 1 day and 2 week generation times), we observe the greatest anabolic activity diversity in the slowest growing populations. By using heavy water to constrain cellular growth activity, we can further infer the relative contributions of ammonium vs. amino acid assimilation to the cellular nitrogen pool. The approach described here can be applied to disentangle individual cell activities even in nutritionally complex environments.", "doi": "10.1111/1462-2920.12752", "pmcid": "PMC4587896", "issn": "1462-2912", "publisher": "Wiley", "publication": "Environmental Microbiology", "publication_date": "2015-07", "series_number": "7", "volume": "17", "issue": "7", "pages": "2542-2556" }, { "id": "authors:x6xeh-9s062", "collection": "authors", "collection_id": "x6xeh-9s062", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20150105-115434812", "type": "article", "title": "Accurate analysis of shallowly implanted solar wind ions by SIMS backside depth profiling", "author": [ { "family_name": "Heber", "given_name": "Veronika S.", "clpid": "Heber-V-S" }, { "family_name": "McKeegan", "given_name": "Kevin D.", "clpid": "McKeegan-K-D" }, { "family_name": "Burnett", "given_name": "Donald S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Duprat", "given_name": "Jean", "clpid": "Duprat-J" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Jurewicz", "given_name": "Amy J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-A-J-G" }, { "family_name": "Olinger", "given_name": "Chad T.", "orcid": "0000-0002-9509-6345", "clpid": "Olinger-C-T" }, { "family_name": "Smith", "given_name": "Stephen P.", "clpid": "Smith-S-P" } ], "abstract": "A method to quantitatively determine the fluences of shallowly-implanted solar wind ions returned to Earth by the Genesis Discovery mission is described. Through backside depth-profiling, we recover nearly complete depth profiles of implanted solar wind for several nonvolatile elements, including Mg, Al, Ca, Cr, and, to a lesser extent, Na, in silicon targets that collected bulk solar wind and solar wind from specific velocity regimes. We also determine the fluences of the volatile elements C, N, and O in silicon targets that collected bulk solar wind. By the use of appropriately calibrated ion implanted standards, fluences as low as 2 \u00d7 10^(10) atoms cm^(\u22122) can be determined with precision and accuracy typically in the few percent range. Specific approaches to sample preparation, sputtering artifacts during depth profiling by secondary ion mass spectrometry, and quantification including the production of ion implant standards are discussed.", "doi": "10.1016/j.chemgeo.2014.10.003", "issn": "0009-2541", "publisher": "Elsevier", "publication": "Chemical Geology", "publication_date": "2014-12-18", "volume": "390", "pages": "61-73" }, { "id": "authors:wfx8h-mxn24", "collection": "authors", "collection_id": "wfx8h-mxn24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141121-085345563", "type": "article", "title": "Perchlorate in The Great Lakes: Isotopic Composition and Origin", "author": [ { "family_name": "Poghosyan", "given_name": "Armen", "clpid": "Poghosyan-A" }, { "family_name": "Sturchio", "given_name": "Neil C.", "clpid": "Sturchio-N-C" }, { "family_name": "Morrison", "given_name": "Candice G.", "clpid": "Morrison-C-G" }, { "family_name": "Beloso", "given_name": "Abelardo D., Jr.", "clpid": "Beloso-A-D-Jr" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Jackson", "given_name": "W. Andrew", "clpid": "Jackson-W-A" }, { "family_name": "Hatzinger", "given_name": "Paul B.", "clpid": "Hatzinger-P-B" } ], "abstract": "Perchlorate is a persistent and mobile contaminant in the environment with both natural and anthropogenic sources. Stable isotope ratios of oxygen (\u03b4^(18)O, \u0394^(17)O) and chlorine (\u03b4^(37)Cl) along with the abundance of the radioactive isotope ^(36)Cl were used to trace perchlorate sources and behavior in the Laurentian Great Lakes. These lakes were selected for study as a likely repository of recent atmospheric perchlorate deposition. Perchlorate concentrations in the Great Lakes range from 0.05 to 0.13 \u03bcg per liter. \u0394^(37)Cl values of perchlorate from the Great Lakes range from +3.0\u2030 (Lake Ontario) to +4.0\u2030 (Lake Superior), whereas \u03b4^(18)O values range from \u22124.1\u2030 (Lake Superior) to +4.0\u2030 (Lake Erie). Great Lakes perchlorate has mass-independent oxygen isotopic variations with positive \u0394^(17)O values (+1.6\u2030 to +2.7\u2030) divided into two distinct groups: Lake Superior (+2.7\u2030) and the other four lakes (\u223c+1.7\u2030). The stable isotopic results indicate that perchlorate in the Great Lakes is dominantly of natural origin, having isotopic composition resembling that measured for indigenous perchlorate from preindustrial groundwaters of the western USA. The ^(36)Cl/Cl ratio of perchlorate varies widely from 7.4 \u00d7 10^(\u201312) (Lake Ontario) to 6.7 \u00d7 10^(\u201311) (Lake Superior). These ^(36)ClO_4\u2013 abundances are consistent with an atmospheric origin of perchlorate in the Great Lakes. The relatively high ^(36)ClO_4\u2013 abundances in the larger lakes (Lakes Superior and Michigan) could be explained by the presence of ^(36)Cl-enriched perchlorate deposited during the period of elevated atmospheric ^(36)Cl activity following thermonuclear bomb tests in the Pacific Ocean.", "doi": "10.1021/es502796d", "issn": "0013-936X", "publisher": "American Chemical Society", "publication": "Environmental Science and Technology", "publication_date": "2014-10-07", "series_number": "19", "volume": "48", "issue": "19", "pages": "11146-11153" }, { "id": "authors:84fxz-bpv46", "collection": "authors", "collection_id": "84fxz-bpv46", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141113-092002535", "type": "article", "title": "Phosphate-halogen metasomatism of lunar granulite 79215: Impact-induced fractionation of volatiles and incompatible elements", "author": [ { "family_name": "Treiman", "given_name": "Allan H.", "orcid": "0000-0002-8073-2839", "clpid": "Treiman-A-H" }, { "family_name": "Boyce", "given_name": "Jeremy W.", "clpid": "Boyce-J-W" }, { "family_name": "Gross", "given_name": "Juliane", "clpid": "Gross-J" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Stolper", "given_name": "Edward M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "In the last decade, it has been recognized that the Moon contains significant proportions of volatile elements (H, F, Cl), and that they are transported through the lunar crust and across its surface. Here, we document a significant segment of that volatile cycle in lunar granulite breccia 79215: impact-induced remobilization of volatiles, and vapor-phase transport with extreme elemental fractionation. 79215 contains ~1% volume of fluorapatite, Ca_5(PO_4)_3(F,Cl,OH), in crystals to 1 mm long, which is reflected in its analyzed abundances of F, Cl, and P. The apatite has a molar F/Cl ratio of ~10, and contains only 25 ppm OH and low abundances of the rare earth elements (REE). The chlorine in the apatite is isotopically heavy, at \u03b4^(37)Cl = +32.7 \u00b1 1.6\u2030. Hydrogen in the apatite is heavy at \u03b4D = +1060 \u00b1 180\u2030; much of that D came from spallogenic nuclear reactions, and the original \u03b4D was lower, between +350\u2030 and +700\u2030. Unlike other P-rich lunar rocks (e.g., 65015), 79215 lacks abundant K and REE, and other igneous incompatible elements characteristic of the lunar KREEP component. Here, we show that the P and halogens in 79215 were added to an otherwise \"normal\" granulite by vapor-phase metasomatism, similar to rock alteration by fumarolic exhalations as observed on Earth. The ultimate source of the P and halogens was most likely KREEP, it being the richest reservoir of P on the Moon, and 79215 having H and Cl isotopic compositions consistent with KREEP. A KREEP-rich rock was heated and devolatilized by an impact event. This vapor was fractionated by interaction with solid phases, including merrillite (a volatile-free phosphate mineral), a Fe-Ti oxide, and a Zr-bearing phase. These solids removed REE, Th, Zr, Hf, etc., from the vapor, and allowed the vapor to transport primarily P, F, and Cl, with lesser proportions of Ba and U into 79215. Vapor-deposited crystals of apatite (to 30 \u03bcm) are known in some lunar regolith samples, but lunar vapor has not (before this) been implicated in significant mass transfer. It seems unlikely, however, that phosphate-halogen metasomatism is related to the high-Th/Sm abundance ratios of this and other lunar magnesian granulites. The metasomatism of 79215 emphasizes the importance of impact heating in the lunar volatile cycle, both in mobilizing volatile components into vapor and in generating strong elemental fractionations.", "doi": "10.2138/am-2014-4822", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2014-10", "series_number": "10", "volume": "99", "issue": "10", "pages": "1860-1870" }, { "id": "authors:5qwtj-j7w30", "collection": "authors", "collection_id": "5qwtj-j7w30", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141023-105133561", "type": "article", "title": "Characterizing Early Solar System Fluids on the Allende (CV3) Parent Body: Nanosims Study of Phosphate Volatile Contents", "author": [ { "family_name": "Dyl", "given_name": "K. A.", "clpid": "Dyl-K-A" }, { "family_name": "Boyce", "given_name": "J. W.", "clpid": "Boyce-J-W" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Bland", "given_name": "P. A.", "clpid": "Bland-P-A" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "Much of our knowledge about the early Solar System comes from the study of CV3 meteorites, in particular Allende. Hydrothermal alteration is recognized as an important, ubiquitous process within these rocks (e.g. [1]). Nevertheless, we know little regarding the nature of these fluids. Volatile element abundances in phosphates from carbonaceous chondrites could constrain relative fugacities of H_2O, HF and HCl in the fluid present during metasomatism in primitive planetesimals.", "doi": "10.1111/maps.12359", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2014-09", "series_number": "S1", "volume": "49", "issue": "S1", "pages": "A104" }, { "id": "authors:1y1yw-j4271", "collection": "authors", "collection_id": "1y1yw-j4271", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140714-103246841", "type": "article", "title": "Chemical zonation in olivine-hosted melt inclusions", "author": [ { "family_name": "Newcombe", "given_name": "M. E.", "orcid": "0000-0002-8450-768X", "clpid": "Newcombe-M-E" }, { "family_name": "Fabbrizio", "given_name": "A.", "clpid": "Fabbrizio-A" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Le Voyer", "given_name": "M.", "clpid": "Le-Voyer-M" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Saal", "given_name": "A. E.", "clpid": "Saal-A-E" }, { "family_name": "Stolper", "given_name": "E. M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "Significant zonation in major, minor, trace, and volatile elements has been documented in naturally glassy olivine-hosted melt inclusions from the Siqueiros Fracture Zone and the Galapagos Islands. Components with a higher concentration in the host olivine than in the melt (e.g., MgO, FeO, Cr_2O_3, and MnO) are depleted at the edges of the zoned melt inclusions relative to their centers, whereas except for CaO, H_2O, and F, components with a lower concentration in the host olivine than in the melt (e.g., Al_2O_3, SiO_2, Na_2O, K_2O, TiO_2, S, and Cl) are enriched near the melt inclusion edges. This zonation is due to formation of an olivine-depleted boundary layer in the adjacent melt in response to cooling and crystallization of olivine on the walls of the melt inclusions, concurrent with diffusive propagation of the boundary layer toward the inclusion center. Concentration profiles of some components in the melt inclusions exhibit multicomponent diffusion effects such as uphill diffusion (CaO, FeO) or slowing of the diffusion of typically rapidly diffusing components (Na_2O, K_2O) by coupling to slow diffusing components such as SiO_2 and Al_2O_3. Concentrations of H_2O and F decrease toward the edges of some of the Siqueiros melt inclusions, suggesting either that these components have been lost from the inclusions into the host olivine late in their cooling histories and/or that these components are exhibiting multicomponent diffusion effects. A model has been developed of the time-dependent evolution of MgO concentration profiles in melt inclusions due to simultaneous depletion of MgO at the inclusion walls due to olivine growth and diffusion of MgO in the melt inclusions in response to this depletion. Observed concentration profiles were fit to this model to constrain their thermal histories. Cooling rates determined by a single-stage linear cooling model are 150\u201313,000 \u00b0C h^(\u22121) from the liquidus down to ~1,000 \u00b0C, consistent with previously determined cooling rates for basaltic glasses; compositional trends with melt inclusion size observed in the Siqueiros melt inclusions are described well by this simple single-stage linear cooling model. Despite the overall success of the modeling of MgO concentration profiles using a single-stage cooling history, MgO concentration profiles in some melt inclusions are better fit by a two-stage cooling history with a slower-cooling first stage followed by a faster-cooling second stage; the inferred total duration of cooling from the liquidus down to ~1,000 \u00b0C ranges from 40 s to just over 1 h. Based on our observations and models, compositions of zoned melt inclusions (even if measured at the centers of the inclusions) will typically have been diffusively fractionated relative to the initially trapped melt; for such inclusions, the initial composition cannot be simply reconstructed based on olivine-addition calculations, so caution should be exercised in application of such reconstructions to correct for post-entrapment crystallization of olivine on inclusion walls. Off-center analyses of a melt inclusion can also give results significantly fractionated relative to simple olivine crystallization. All melt inclusions from the Siqueiros and Galapagos sample suites exhibit zoning profiles, and this feature may be nearly universal in glassy, olivine-hosted inclusions. If so, zoning profiles in melt inclusions could be widely useful to constrain late-stage syneruptive processes and as natural diffusion experiments.", "doi": "10.1007/s00410-014-1030-6", "issn": "0010-7999", "publisher": "Springer", "publication": "Contributions to Mineralogy and Petrology", "publication_date": "2014-07", "series_number": "1", "volume": "168", "issue": "1", "pages": "Art. No. 1030" }, { "id": "authors:j6m07-5ch38", "collection": "authors", "collection_id": "j6m07-5ch38", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140505-132007730", "type": "article", "title": "Impact-induced shock and the formation of natural quasicrystals in the early solar system", "author": [ { "family_name": "Hollister", "given_name": "Lincoln S.", "clpid": "Hollister-L-S" }, { "family_name": "Bindi", "given_name": "Luca", "orcid": "0000-0003-1168-7306", "clpid": "Bindi-L" }, { "family_name": "Yao", "given_name": "Nan", "clpid": "Yao-Nan" }, { "family_name": "Poirier", "given_name": "Gerald R.", "clpid": "Poirier-G-R" }, { "family_name": "Andronicos", "given_name": "Christopher L.", "clpid": "Andronicos-C-L" }, { "family_name": "MacPherson", "given_name": "Glenn J.", "clpid": "MacPherson-G-J" }, { "family_name": "Lin", "given_name": "Chaney", "clpid": "Lin-Chaney" }, { "family_name": "Distler", "given_name": "Vadim V.", "clpid": "Distler-V-V" }, { "family_name": "Eddy", "given_name": "Michael P.", "clpid": "Eddy-M-P" }, { "family_name": "Kostin", "given_name": "Alexander", "clpid": "Kostin-A" }, { "family_name": "Kryachko", "given_name": "Valery", "clpid": "Kryachko-V" }, { "family_name": "Steinhardt", "given_name": "William M.", "clpid": "Steinhardt-W-M" }, { "family_name": "Yudovskaya", "given_name": "Marina", "clpid": "Yudovskaya-M" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Clarke", "given_name": "Jamil J.", "clpid": "Clarke-J-J" }, { "family_name": "Steinhardt", "given_name": "Paul J.", "clpid": "Steinhardt-P-J" } ], "abstract": "The discovery of a natural quasicrystal, icosahedrite (Al_(63)Cu_(24)Fe_(13)), accompanied by khatyrkite (CuAl_2) and cupalite (CuAl) in the CV3 carbonaceous chondrite Khatyrka has posed a mystery as to what extraterrestrial processes led to the formation and preservation of these metal alloys. Here we present a range of evidence, including the discovery of high-pressure phases never observed before in a CV3 chondrite, indicating that an impact shock generated a heterogeneous distribution of pressures and temperatures in which some portions reached at least 5\u2009GPa and 1,200\u2009\u00b0C. The conditions were sufficient to melt Al\u2013Cu-bearing minerals, which then rapidly solidified into icosahedrite and other Al\u2013Cu metal phases. The meteorite also contains heretofore unobserved phases of iron\u2013nickel and iron sulphide with substantial amounts of Al and Cu. The presence of these phases in Khatyrka provides further proof that the Al\u2013Cu alloys are natural products of unusual processes that occurred in the early solar system.", "doi": "10.1038/ncomms5040", "issn": "2041-1723", "publisher": "Nature Publishing Group", "publication": "Nature Communications", "publication_date": "2014-06-13", "series_number": "6", "volume": "5", "issue": "6", "pages": "Art. No. 4040" }, { "id": "authors:g5568-y1282", "collection": "authors", "collection_id": "g5568-y1282", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140527-102509954", "type": "article", "title": "Phosphate minerals in LL chondrites: A record of the action of fluids during metamorphism on ordinary chondrite parent bodies", "author": [ { "family_name": "Jones", "given_name": "Rhian H.", "clpid": "Jones-R-H" }, { "family_name": "McCubbin", "given_name": "Francis M.", "clpid": "McCubbin-F-M" }, { "family_name": "Dreeland", "given_name": "Linda", "clpid": "Dreeland-L" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Burger", "given_name": "Paul V.", "clpid": "Burger-P-V" }, { "family_name": "Shearer", "given_name": "Charles K.", "clpid": "Shearer-C-K" } ], "abstract": "Ordinary chondrites contain two phosphate minerals, merrillite and chlorapatite, both of which are secondary minerals that developed in response to metamorphism on the chondrite parent bodies. We have studied the phosphate mineralogy of four LL chondrites, of petrologic types 3.9\u20136, in order to determine the petrogenesis of the two minerals and interpret the conditions under which they formed. Characterization of merrillite and apatite includes textural observations, mineral compositions determined by electron probe microanalysis, and ion microprobe analyses of trace element and volatile anion elemental abundances. Initial formation of phosphate minerals during mild metamorphism, to petrologic type 4 conditions, resulted in oxidation of P that was originally incorporated in metal, and growth of merrillite as inclusions within metal grains. Subsequent development of both phosphate minerals occurred in response to diffusional equilibration, possible precipitation from fluids as well as replacement reactions resulting from interactions with fluids. Porosity and vein-filling textures in both merrillite and chlorapatite, as well as textures indicating replacement of merrillite by chlorapatite, support a model in which fluid played a significant role and suggest an interface-coupled dissolution\u2013reprecipitation mechanism during metasomatism. Some associations of phosphate minerals with chromite-plagioclase assemblages suggest that phosphate minerals could also be related to impact processes, either as precipitation from an impact melt or as a result of interactions with a fluid or vapor derived from an impact melt. Fluid compositions may have been water-bearing initially, at low temperatures of metamorphism, but later evolved to become halogen-rich and very dry. Late-stage halogen-rich fluids that dominated during cooling of LL chondrite material may have been derived from vaporization of partial melts in the interior of the parent body. Overall, the LL chondrite parent body underwent a complex chemical evolution, in which metasomatism played a significant role.", "doi": "10.1016/j.gca.2014.01.027", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2014-05-01", "volume": "132", "pages": "120-140" }, { "id": "authors:0dsks-cxg43", "collection": "authors", "collection_id": "0dsks-cxg43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140408-101812632", "type": "article", "title": "SQUID\u2013SIMS is a useful approach to uncover primary signals in the Archean sulfur cycle", "author": [ { "family_name": "Fischer", "given_name": "Woodward W.", "orcid": "0000-0002-8836-3054", "clpid": "Fischer-W-W" }, { "family_name": "Fike", "given_name": "David A.", "orcid": "0000-0003-2848-0328", "clpid": "Fike-D-A" }, { "family_name": "Johnson", "given_name": "Jane E.", "clpid": "Johnson-J-E" }, { "family_name": "Raub", "given_name": "Timothy D.", "orcid": "0000-0002-7471-0246", "clpid": "Raub-T-D" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Kirschvink", "given_name": "Joseph L.", "orcid": "0000-0001-9486-6689", "clpid": "Kirschvink-J-L" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" } ], "abstract": "Many aspects of Earth's early sulfur cycle, from the origin of mass-anomalous fractionations to the degree of biological participation, remain poorly understood\u2014in part due to complications from postdepositional diagenetic and metamorphic processes. Using a combination of scanning high-resolution magnetic superconducting quantum interference device (SQUID) microscopy and secondary ion mass spectrometry (SIMS) of sulfur isotopes (^(32)S, ^(33)S, and ^(34)S), we examined drill core samples from slope and basinal environments adjacent to a major Late Archean (\u223c2.6\u20132.5 Ga) marine carbonate platform from South Africa. Coupled with petrography, these techniques can untangle the complex history of mineralization in samples containing diverse sulfur-bearing phases. We focused on pyrite nodules, precipitated in shallow sediments. These textures record systematic spatial differences in both mass-dependent and mass-anomalous sulfur-isotopic composition over length scales of even a few hundred microns. Petrography and magnetic imaging demonstrate that mass-anomalous fractionations were acquired before burial and compaction, but also show evidence of postdepositional alteration 500 million y after deposition. Using magnetic imaging to screen for primary phases, we observed large spatial gradients in \u0394^(33)S (>4\u2030) in nodules, pointing to substantial environmental heterogeneity and dynamic mixing of sulfur pools on geologically rapid timescales. In other nodules, large systematic radial \u03b4^(34)S gradients (>20\u2030) were observed, from low values near their centers increasing to high values near their rims. These fractionations support hypotheses that microbial sulfate reduction was an important metabolism in organic-rich Archean environments\u2014even in an Archean ocean basin dominated by iron chemistry.", "doi": "10.1073/pnas.1322577111", "pmcid": "PMC3992679", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2014-04-15", "series_number": "15", "volume": "111", "issue": "15", "pages": "5468-5473" }, { "id": "authors:3wgss-ket32", "collection": "authors", "collection_id": "3wgss-ket32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140428-094609669", "type": "article", "title": "Zonation of H_(2)O and F Concentrations around Melt Inclusions in Olivines", "author": [ { "family_name": "Le Voyer", "given_name": "Marion", "clpid": "Le-Voyer-M" }, { "family_name": "Asimow", "given_name": "Paul D.", "orcid": "0000-0001-6025-8925", "clpid": "Asimow-P-D" }, { "family_name": "Mosenfelder", "given_name": "Jed L.", "clpid": "Mosenfelder-J-L" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wallace", "given_name": "Paul J.", "clpid": "Wallace-P-J" }, { "family_name": "Schiano", "given_name": "Pierre", "clpid": "Schiano-P" }, { "family_name": "Stolper", "given_name": "Edward M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" } ], "abstract": "Studies of both naturally quenched and experimentally reheated melt inclusions have established that they can lose or gain H_(2)O after entrapment in their host mineral, before or during eruption. Here we report nanoSIMS analyses of H2O, Cl and F in olivine around melt inclusions from two natural basaltic samples: one from the Sommata cinder cone on Vulcano Island in the Aeolian arc and the other from the Jorullo cinder cone in the Trans-Mexican Volcanic Belt. Our results constrain olivine/basaltic melt partition coefficients and allow assessment of mechanisms of volatile loss from melt inclusions in natural samples. Cl contents in olivine from both samples are mostly below detection limits (\u22640\u00b703 \u00b1 0\u00b701 ppm), with no detectable variation close to the melt inclusions. Assuming a maximum Cl content of 0\u00b703 ppm for all olivines, maximum estimates for Cl partition coefficients between olivine and glass are 0\u00b700002 \u00b1 0\u00b700002. Olivines from the two localities display contrasting H_(2)O and F compositions: Sommata olivines contain 27 \u00b1 11 ppm H_(2)O and 0\u00b728 \u00b1 0\u00b707 ppm F, whereas Jorullo olivines have lower and proportionately more variable H_(2)O and F (11 \u00b1 12 ppm and 0\u00b712 \u00b1 0\u00b709 ppm, respectively; uncertainties are two standard deviations for the entire population). The variations of H_(2)O and F contents in the olivines exhibit clear zonation patterns, increasing with proximity to melt inclusions. This pattern was most probably generated during transfer of volatiles out of the inclusions through the host olivine. H_(2)O concentration gradients surrounding melt inclusions are roughly concentric, but significantly elongated parallel to the crystallographic a-axis of olivine. Because of this preferential crystallographic orientation, this pattern is consistent with H_(2)O loss that is rate-limited by the 'proton\u2013polaron' mechanism of H diffusion in olivine. Partition coefficients based on olivine compositions immediately adjacent to melt inclusions are 0\u00b70007 \u00b1 0\u00b70003 for H_(2)O and 0\u00b70005 \u00b1 0\u00b70003 for F. The H_(2)O and F diffusion profiles most probably formed in response to a decrease in the respective fugacities in the external melt, owing to either degassing or mixing with volatile-poor melt. Volatile transport out of inclusions might also have been driven in part by increases in the fugacity within the inclusion owing to post-entrapment crystallization. In the case of F, because of the lack of data on F diffusion in olivine, any interpretation of the measured F gradients is speculative. In the case of H_(2)O, we model the concentration gradients using a numerical model of three-dimensional anisotropic diffusion of H, where initial conditions include both H2O decrease in the external melt and post-entrapment enrichment of H_(2)O in the inclusions. The model confirms that external degassing is the dominant driving force, showing that the orientation of the anisotropy in H diffusion is consistent with the proton\u2013polaron diffusion mechanism in olivine. The model also yields an estimate of the initial H_(2)O content of the Sommata melt inclusions before diffusive loss of 6 wt % H_(2)O. The findings provide new insights on rapid H_(2)O loss during magma ascent and improve our ability to assess the fidelity of the H_(2)O record from melt inclusions.", "doi": "10.1093/petrology/egu003", "issn": "0022-3530", "publisher": "Oxford University Press", "publication": "Journal of Petrology", "publication_date": "2014-04", "series_number": "4", "volume": "55", "issue": "4", "pages": "685-707" }, { "id": "authors:zg01e-erb35", "collection": "authors", "collection_id": "zg01e-erb35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140807-150733584", "type": "article", "title": "Field and microanalytical isotopic investigation of ultradepleted in ^(18)O Paleoproterozoic \"Slushball Earth\" rocks from Karelia, Russia", "author": [ { "family_name": "Bindeman", "given_name": "I. N.", "clpid": "Bindeman-I-N" }, { "family_name": "Serebryakov", "given_name": "N. S.", "clpid": "Serebryakov-N-S" }, { "family_name": "Schmitt", "given_name": "A. K.", "clpid": "Schmitt-A-K" }, { "family_name": "Vazquez", "given_name": "J. A.", "clpid": "Vazquez-J-A" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Azimov", "given_name": "P. Ya.", "clpid": "Azimov-P-Ya" }, { "family_name": "Astafiev", "given_name": "B. Yu.", "clpid": "Astafiev-B-Yu" }, { "family_name": "Palandri", "given_name": "J.", "clpid": "Palandri-J" }, { "family_name": "Dobrzhinetskaya", "given_name": "L.", "clpid": "Dobrzhinetskaya-L" } ], "abstract": "The 1.85 Ga Belomorian Belt, Karelia, Russia, hosts ultralow \u03b4^(18)O and \u03b4D (as low as \u221227.3\u2030 and \u2212235\u2030 standard mean ocean water [SMOW], respectively), high-Al gneisses and amphibolites that we attribute to the Paleoproterozoic \"Slushball Earth\" glaciation. They now occur in at least 11 localities spanning 450 km. To constrain distribution of ^(18)O-depleted rocks, we performed detailed field mapping in Khitostrov, where \u03b4^(18)O values are the lowest. Using 430 new and previously published laser fluorination isotope analyses, we show that the elongated, concentrically zoned area of \u03b4^(18)O depletion is greater than 6 \u00d7 2 km in areal extent, \u223c10 times larger than previously thought. Relationships between \u03b4^(17)O versus \u03b4^(18)O strictly adhere to the equilibrium terrestrial mass-dependent fractionation with a slope of 0.527. We also report the results of ion microprobe U-Pb geochronology of zircons coupled with co-registered oxygen isotope spot analyses for mafic intrusions and host gneisses in six localities. The 2.9\u20132.7 Ga gneiss zircon cores are normal in \u03b4^(18)O (5\u2030\u20137\u2030). They show truncated oscillatory cathodoluminescence (CL) patterns and rounded shape indicative of original igneous crystallization with subsequent detrital overprinting. A younger 2.6\u20132.55 Ga metamorphic zircon domain with normal \u03b4^(18)O, low Th/U, dark cathodoluminescence, and also with rounded crystal morphology is commonly preserved. Cores are surrounded by ubiquitous rims highly depleted in \u03b4^(18)O (re-)crystallized with Svecofennian (1.85\u20131.89 Ga) ages. Rims are interpreted as metamorphic due to bright and uniform CL and Th/U <0.05. Mafic intrusions preserve few igneous zircon crystals between ca. 2.23 and 2.4 Ga in age, but neoblastic zircon in these intrusions originated mostly during 1.85 Ga Svecofennian metamorphism. The \u03b4^(18)O-age relationship for metamorphic rims in zircon and corundum grains suggests that \u03b4^(18)O values of fluids were subtly increasing with time during metamorphism. Large metamorphic corundum grains have \u223c3\u2030 intracrystalline \u03b4^(18)O isotope zonation from \u201324 to \u201321\u2030, which likely developed during interaction with metamorphic fluids. The Zr-in-rutile geothermometer temperatures are in the range of 760 to 720 \u00b0C, in accordance with mineral assemblages and amphibolite metamorphic grade. High and irregular rare-earth element (REE) abundance in cores and rims of many zircons correlates with high phosphorus content and is explained by nanometer-scale xenotime and monazite inclusions, likely in metamict zones during 1.85 Ga Svecofennian metamorphism. A survey of oxygen isotopes in ultrahigh-pressure diamond and coesite-bearing metamorphic terrains around the world reveals normal to high-\u03b4^(18)O values, suggesting that the low \u03b4^(18)O in metamorphic rocks of Dabie Shan, Kokchetav, and in Karelia, are genetically unrelated to metamorphism. We discuss alternative ways to achieve extreme \u03b4^(18)O depletion by kinetic, Rayleigh, and thermal diffusion processes, and by metamorphism. We prefer an interpretation where the low-\u03b4^(18)O and high-Al signature of the rocks predates metamorphism, and is caused by shallow hydrothermal alteration and partial dissolution of the protolith surrounding shallow mafic intrusions by glacial meltwaters during pan-global Paleoproterozoic \"Slushball Earth\" glaciations between ca. 2.4 and ca. 2.23 Ga.", "doi": "10.1130/GES00952.1", "issn": "1553-040X", "publisher": "Geological Society of America", "publication": "Geosphere", "publication_date": "2014-02-21", "series_number": "2", "volume": "10", "issue": "2", "pages": "308-339" }, { "id": "authors:9c0e8-xd813", "collection": "authors", "collection_id": "9c0e8-xd813", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131024-105248234", "type": "article", "title": "Petrogenetic linkages among fO_2, isotopic enrichments-depletions and crystallization history in Martian basalts. Evidence from the distribution of phosphorus in olivine megacrysts", "author": [ { "family_name": "Shearer", "given_name": "C. K.", "clpid": "Shearer-C-K" }, { "family_name": "Aaron", "given_name": "P. M.", "clpid": "Aaron-P-M" }, { "family_name": "Burger", "given_name": "P. V.", "clpid": "Burger-P-V" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Bell", "given_name": "A. S.", "clpid": "Bell-A-S" }, { "family_name": "Papike", "given_name": "J. J.", "clpid": "Papike-J-J" } ], "abstract": "An important geochemical characteristic of the shergottites is the large range in initial Sr isotopic ratios and initial \u03b5^(Nd) values. The depleted olivine-phyric shergottites are commonly reduced (\u223cIW+1) and exhibit limited variation in fO_2 during crystallization, whereas the enriched olivine-phyric shergottites are more oxidized and exhibit a substantial variation in fO_2 during crystallization (\u223cIW+1 (1 log unit above the iron-w\u00fcstite buffer) to FMQ+0.7 (0.7 log units above the fayalite-magnetite-quartz buffer). Using a reduced, depleted shergottite Y980459 (Y98) and an oxidized, enriched shergottite (NWA1183), we reconstructed the crystallization history of the olivine megacrysts using phosphorus zoning and placed trace element variation and indices of oxygen fugacity into the context of that crystallization history. The olivine megacrysts in Y98 and NWA1183 exhibited various episodes of growth defined by the P zoning. Common to both samples were continuous and discontinuous oscillatory chemical zoning in the outer portions of the olivine megacrysts. However, the morphologies of the cores suggest a xenocrystic origin for the core of Y98 and a phenocrystic origin for the core of NWA1183. Phosphorus in the olivine ranges from less than 0.02 to up to 0.70 wt.% P_2O_5. The P in the olivine megacrysts manifests subtle, but real differences, in the P content of different shergottite melts, incompatible element behavior of P during olivine crystallization, and solute trapping during periods of rapid olivine growth. Although P should behave incompatibly in basaltic systems, there is little relationship between the isotopic characteristics and P content in the enriched-depleted array of shergottites. In the olivine, Al is generally correlated with P enrichment and reflects a coupled substitution of P\u2013Al. On the other hand, V is not correlated with P in Y98, but correlated with P in the oscillatory zoned regions of the olivine in NWA1183. The changes in correlation to P may reflect differences in V valance state during olivine crystallization. Within the crystallization histories defined by the P zoning in olivine, the calculated fO_2 remains fairly constant at \u223cIW+1 for Y98, but changes dramatically for NWA1183 from olivine core to rim (\u223cIW+1.8 to FMQ+.07). Numerous lines of evidence suggest that the changes in fO_2 during olivine crystallization may reflect auto-oxidation that may be at least partially due to degassing of the NWA1183 magma prior to eruption. These observations suggest a limited variation in the fO_2 of the Martian mantle (IW to IW+1), that enriched and depleted sources for the shergottites reside in the mantle, and that magmas produced in these sources have different capabilities for changing their redox state during crystallization.", "doi": "10.1016/j.gca.2013.06.034", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2013-11-01", "volume": "120", "pages": "17-38" }, { "id": "authors:js0gq-ffa24", "collection": "authors", "collection_id": "js0gq-ffa24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131121-131800523", "type": "article", "title": "Accurate Mg/Ca, Sr/Ca, and Ba/Ca ratio measurements in carbonates by SIMS and NanoSIMS and an assessment of heterogeneity in common calcium carbonate standards", "author": [ { "family_name": "Gabitov", "given_name": "R. I.", "clpid": "Gabitov-R-I" }, { "family_name": "Gagnon", "given_name": "A. C.", "clpid": "Gagnon-Alexander-C" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "orcid": "0000-0001-5768-7593", "clpid": "Eiler-J-M" }, { "family_name": "Adkins", "given_name": "J. F.", "orcid": "0000-0002-3174-5190", "clpid": "Adkins-J-F" } ], "abstract": "As archives of past climate variability, the micron and sub-micron scales of element:calcium (Me/Ca) variability in both biogenic and inorganic carbonates contain important geochemical information. Ideally working at smaller and smaller scales leads to higher temporal resolution of past changes, but more often it has revealed the strong overprint of other processes on the climate signal. Therefore, the role of SIMS and NanoSIMS techniques in studying paleoenvironmental proxies continues to increase. We evaluate the accuracy and precision of the CAMECA ims 7F-GEO and NanoSIMS-50L ion probes for measurements of Sr/Ca, Mg/Ca, and Ba/Ca ratios in carbonate minerals. Nine carbonate reference materials were examined for their \u2078\u2078Sr/\u2074\u00b2Ca, \u00b2\u2074Mg/\u2074\u00b2Ca, and \u00b9\u00b3\u2078Ba/\u2074\u00b2Ca ratios using a primary O\u207b beam with spot sizes of 20\u201340 \u03bcm (SIMS) and 0.8\u20132 \u03bcm (NanoSIMS). To assess accuracy, seven of these standards were analyzed for Sr/Ca and Mg/Ca with ID-ICP-MS. Variability in the elemental ratios arising from drift and changes in the tuning of the ims 7F-GEO over a nine month period is smaller than the chemical heterogeneity of the most frequently analyzed standards (OKA and Blue-CC). Across a whole crystal, Blue-CC is more homogeneous (1\u03c3 of 2.39% and 1.60% for Sr/Ca and Mg/Ca respectively) than OKA, but in the bulk matrix of OKA there is even less variability (1\u03c3 of 0.85% and 0.83% respectively). We find that carbonate samples can be accurately normalized to carbonate standards with significantly different absolute Me/Ca ratios. NanoSIMS intensity ratios follow counting statistics better than \u00b1 1% (2\u03c3) at any one spot, but conversion to Me/Ca ratios increases the uncertainty. Two factors give rise to this limitation. First, the spatial heterogeneity of nominally homogeneous standards can lead to accuracy offsets that are as large as the ranges quoted above. Second, the NanoSIMS generates higher instrumental mass fractionation relative to SIMS. The combination of three different analytical techniques demonstrates that Blue-CC and homogeneous calcite zones in OKA are promising reference materials for precise analyses. Accuracy is crucially dependent on making independent measurements on exactly the same crystal of standard used in the SIMS and NanoSIMS machines.", "doi": "10.1016/j.chemgeo.2013.07.019", "issn": "0009-2541", "publisher": "Elsevier", "publication": "Chemical Geology", "publication_date": "2013-10-09", "volume": "356", "pages": "94-108" }, { "id": "authors:dhmrq-eb912", "collection": "authors", "collection_id": "dhmrq-eb912", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131118-094056163", "type": "article", "title": "Khatyrka, a new CV3 find from the Koryak Mountains, Eastern Russia", "author": [ { "family_name": "MacPherson", "given_name": "Glenn J.", "clpid": "MacPherson-G-J" }, { "family_name": "Andronicos", "given_name": "Christopher L.", "clpid": "Andronicos-C-L" }, { "family_name": "Bindi", "given_name": "Luca", "orcid": "0000-0003-1168-7306", "clpid": "Bindi-L" }, { "family_name": "Distler", "given_name": "Vadim V.", "clpid": "Distler-V-V" }, { "family_name": "Eddy", "given_name": "Michael P.", "clpid": "Eddy-M-P" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hollister", "given_name": "Lincoln S.", "clpid": "Hollister-L-S" }, { "family_name": "Kostin", "given_name": "Alexander", "clpid": "Kostin-A" }, { "family_name": "Kryachko", "given_name": "Valery", "clpid": "Kryachko-V" }, { "family_name": "Steinhardt", "given_name": "William M.", "clpid": "Steinhardt-W-M" }, { "family_name": "Yudovskaya", "given_name": "Marina", "clpid": "Yudovskaya-M" }, { "family_name": "Steinhardt", "given_name": "Paul J.", "clpid": "Steinhardt-P-J" } ], "abstract": "A new meteorite find, named Khatyrka, was recovered from eastern Siberia as a result of a search for naturally occurring quasicrystals. The meteorite occurs as clastic grains within postglacial clay-rich layers along the banks of a small stream in the Koryak Mountains, Chukotka Autonomous Okrug of far eastern Russia. Some of the grains are clearly chondritic and contain Type IA porphyritic olivine chondrules enclosed in matrices that have the characteristic platy olivine texture, matrix olivine composition, and mineralogy (olivine, pentlandite, nickel-rich iron-nickel metal, nepheline, and calcic pyroxene [diopside-hedenbergite solid solution]) of oxidized-subgroup CV3 chondrites. A few grains are fine-grained spinel-rich calcium-aluminum-rich inclusions with mineral oxygen isotopic compositions again typical of such objects in CV3 chondrites. The chondritic and CAI grains contain small fragments of metallic copper-aluminum-iron alloys that include the quasicrystalline phase icosahedrite. One grain is an achondritic intergrowth of Cu-Al metal alloys and forsteritic olivine \u00b1 diopsidic pyroxene, both of which have meteoritic (CV3-like) oxygen isotopic compositions. Finally, some grains consist almost entirely of metallic alloys of aluminum + copper \u00b1 iron. The Cu-Al-Fe metal alloys and the alloy-bearing achondrite clast are interpreted to be an accretionary component of what otherwise is a fairly normal CV3 (oxidized) chondrite. This association of CV3 chondritic grains with metallic copper-aluminum alloys makes Khatyrka a unique meteorite, perhaps best described as a complex CV3 (ox) breccia.", "doi": "10.1111/maps.12170", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2013-08", "series_number": "8", "volume": "48", "issue": "8", "pages": "1499-1514" }, { "id": "authors:s580y-c8s85", "collection": "authors", "collection_id": "s580y-c8s85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130327-111017326", "type": "article", "title": "Sr/Ca sensitivity to aragonite saturation state in cultured subsamples from a single colony of coral: Mechanism of biomineralization during ocean acidification", "author": [ { "family_name": "Gagnon", "given_name": "Alexander C.", "clpid": "Gagnon-Alexander-C" }, { "family_name": "Adkins", "given_name": "Jess F.", "orcid": "0000-0002-3174-5190", "clpid": "Adkins-J-F" }, { "family_name": "Erez", "given_name": "Jonathan", "orcid": "0000-0003-4616-0176", "clpid": "Erez-Jonathan" }, { "family_name": "Eiler", "given_name": "John M.", "orcid": "0000-0001-5768-7593", "clpid": "Eiler-J-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Using a new and rapid NanoSIMS-based method, we quantified the sensitivity of skeletal Sr/Ca in coral to the aragonite saturation state of seawater (\u03a9_(SW)). Skeletal Sr/Ca is a common proxy for temperature while \u03a9_(SW) is a parameter that varied in the past ocean and is predicted to change with continued ocean acidification. Five adult branches of the surface coral Stylophora pistillata were grown at different \u03a9_(SW) from 2.7 to 4.9 (pH of 7.9\u20138.5) but at a constant temperature of 25 \u00b0C. Despite a large range of growth parameters and a twofold range in calcification rates, the average skeletal Sr/Ca of coral exposed to each condition are within 1.2% of each other (2\u03c3 std. dev. of the 5 means). Furthermore, the average skeletal Sr/Ca measured in this study agrees with the results of two previous coral culture experiments conducted at the same temperature but where \u03a9_(SW) was not controlled. These results suggest that aragonite saturation has little or no influence on Sr/Ca paleothermometry over the range of \u03a9_(SW) investigated. Combined with existing data for low \u03a9_(SW) conditions, our results were used to elucidate the mechanisms controlling calcifying fluid acid\u2013base chemistry during coral biomineralization. Assuming that coral drive precipitation through alkalinity pumping, our data suggest that this pumping occurs until the calcifying fluid reaches a target pH. Below a threshold \u03a9_(SW) bounded by 1 < \u03a9_(SW) < 2.4, however, coral do not pump enough alkalinity to reach the target pH and instead pump a maximal but finite amount of alkalinity. In this low \u03a9_(SW) regime, calcifying fluid pH is expected to decrease with \u03a9_(SW). The interplay between these two alkalinity pumping regimes and external seawater composition explain the full range of observed Sr/Ca sensitivity to \u03a9_(SW) and suggest that surface coral may become increasingly sensitive to ocean acidification below a threshold \u03a9_(SW) bounded by 1 < \u03a9_(SW) < 2.4.", "doi": "10.1016/j.gca.2012.11.038", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2013-03-15", "volume": "105", "pages": "240-254" }, { "id": "authors:0mm29-zaq09", "collection": "authors", "collection_id": "0mm29-zaq09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121203-111703108", "type": "article", "title": "D-depleted organic matter and graphite in the Abee enstatite chondrite", "author": [ { "family_name": "Remusat", "given_name": "L.", "clpid": "Remusat-L" }, { "family_name": "Rouzaud", "given_name": "J.-N.", "clpid": "Rouzaud-J-N" }, { "family_name": "Charon", "given_name": "E.", "clpid": "Charon-E" }, { "family_name": "Le Guillou", "given_name": "C.", "clpid": "Le-Guillou-C" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "A combination of NanoSIMS and High resolution transmission electron microscopy (HRTEM) imaging along with Raman spectroscopy was used to characterize the carbonaceous phases in HF/HCl residue of the Abee enstatite chondrite. This acid residue hosts a very D-depleted component (\u03b4D = \u2212480\u2030). This residue is a mixture of graphite and highly disordered insoluble organic matter. The latter exhibits a significant mesoporosity (i.e., 200\u2013500 nm scale), and also shows concentric and elongated stacks of polyaromatic layers. Insoluble organic matter is shown to be the most D-depleted component in Abee. We also determined, by using NanoSIMS, carbon isotopic composition of graphite and insoluble organic matter in the acid residue (\u03b4^(13)C = \u221211.3 \u00b1 2.9\u2030 and \u221228.4 \u00b1 2.2\u2030, respectively).\nWe identified graphite in metal-rich clasts and in the matrix of Abee, associated with enstatite, sulfide and metal, but we could not localize highly disordered organic matter in our section. Regardless, given the vulnerability of organic matter to thermal degradation, we suggest that it was added to Abee parent body during the latest stage of its formation, after any thermal metamorphism or partial melting of Abee parent body.\nA genetic link between organic matter and graphite in Abee is excluded based on our HRTEM and carbon isotopic data. The differences in carbon isotopic compositions between these phases are consistent with previous data obtained by stepwise heating experiments and indicate that graphite is not derived from a pure thermal solid-state graphitization of the organic matter. Rather, we suggest that graphite precipitated from a melt rich in C during the partial melting of the Abee parent body. Insoluble organic matter in Abee has the lowest D/H ratio among the extraterrestrial organics. Organics in most carbonaceous and ordinary chondrites are believed to have been subjected to irradiations in low temperature environments, resulting in a dramatic isotopic fractionation through exchange and reaction with gaseous molecular hydrogen during their synthesis. In contrast, Abee organic matter was likely synthesized in a neutral (i.e., not ionized) environment where thermodynamic processes at equilibrium most likely controlled its isotopic composition.\nThis organic matter could have been accreted in a minor component of Abee like the dark inclusions without (or prior to) exposure to the radiation responsible for D enrichments in other meteoritic organics. During the last brecciation events that have affected the Abee parent body, these inclusions could have been mixed with other Abee components. The properties of this organic matter can be interpreted as an indication that thermodynamic processes acted in the synthesis of organic matter in the protosolar disk, in addition to ion/molecule and gas/grains reaction witnessed by the D-rich insoluble organic matter contained in carbonaceous chondrites.", "doi": "10.1016/j.gca.2012.07.031", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2012-11-01", "series_number": "1", "volume": "96", "issue": "1", "pages": "319-335" }, { "id": "authors:5cgtt-x7c36", "collection": "authors", "collection_id": "5cgtt-x7c36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130107-154912166", "type": "article", "title": "Direct measurement of hydroxyl in the lunar regolith and the origin of lunar surface water", "author": [ { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Taylor", "given_name": "Lawrence A.", "clpid": "Taylor-L-A" } ], "abstract": "Remote sensing discoveries of hydroxyl and water on the\nlunar surface have reshaped our view of the distribution of\nwater and related compounds on airless bodies such as the\nMoon. The origin of this surface water is unclear, but it has been suggested that hydroxyl in the lunar regolith can result from the implantation of hydrogen ions by the solar wind. Here we present Fourier transform infrared spectroscopy and secondary ion mass spectrometry analyses of Apollo samples that reveal the presence of significant amounts of hydroxyl in glasses formed in the lunar regolith by micrometeorite impacts.\nHydrogen isotope compositions of these glasses suggest that\nsome of the observed hydroxyl is derived from solar wind\nsources. Our findings imply that ice in polar cold traps could contain hydrogen atoms ultimately derived from the solar wind, as predicted by early theoretical models of water stability on the lunar surface. We suggest that a similar mechanism may contribute to hydroxyl on the surfaces of other airless terrestrial bodies where the solar wind directly interacts with the surface, such as Mercury and the asteroid 4-Vesta.", "doi": "10.1038/NGEO1601", "issn": "1752-0894", "publisher": "Nature Publishing Group", "publication": "Nature Geoscience", "publication_date": "2012-11", "series_number": "11", "volume": "5", "issue": "11", "pages": "779-782" }, { "id": "authors:nm9n2-mk515", "collection": "authors", "collection_id": "nm9n2-mk515", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120927-120537944", "type": "article", "title": "Petrogenesis of the Northwest Africa 4734 basaltic lunar meteorite", "author": [ { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Li", "given_name": "Xianhua", "clpid": "Li-Xianhua" }, { "family_name": "Li", "given_name": "Qiuli", "clpid": "Li-Qiuli" }, { "family_name": "Liu", "given_name": "Yu", "clpid": "Liu-Yu" }, { "family_name": "Tang", "given_name": "Guoqiang", "clpid": "Tang-Guoqiang" } ], "abstract": "We report the petrography, mineralogy, trace element abundance geochemistry, and Pb\u2013Pb geochronology of the lunar meteorite Northwest Africa (NWA) 4734 and make a comparison with the LaPaz Icefield (LAP) 02205/02224 low-Ti lunar basaltic meteorites. NWA 4734 is an unbrecciated low-Ti mare basalt composed mainly of subophitic-textured pyroxene (60 vol%) and plagioclase (30%). Pyroxene, plagioclase, and olivine exhibit large compositional variations and intra-grain chemical zoning. Pyroxene and plagioclase in NWA 4734 have rare earth element (REE) concentrations and patterns similar to those of the LAPs. The crystallization age of NWA 4734, determined in situ in baddeleyite, is 3073 \u00b1 15 Ma (2\u03c3), nearly identical to that of the LAPs (3039 \u00b1 12 Ma). NWA 4734 and the LAPs have similar textures, modal abundances, mineral chemistry, and crystallization ages, and are most likely source-crater paired on the Moon.\nOne baddeleyite grain in LAP 02224 displays distinctively older and spatially variable ages, from 3349 \u00b1 62 to 3611 \u00b1 62 Ma (2\u03c3), similar to another baddeleyite grain (3109 \u00b1 29 to 3547 \u00b1 21 Ma) reported by Zhang et al. (2010) for the same meteorite. Raman spectra, cathodoluminescence, and stoichiometric studies of the baddeleyite suggest that the two older grains were not endogenic but were trapped by the parental magma. Equilibrium partition calculation shows that the parental melt from which the NWA 4734 plagioclase crystallized has much lower REE contents than its whole rock, indicating an open system during magma evolution. NWA 4734 could have originated from a parental melt with REE concentrations similar to that of the Apollo 12 olivine basalt. The magma likely assimilated a small amount (\u223c4 wt%) of KREEP-rich material during its ascent through the lunar crust.", "doi": "10.1016/j.gca.2012.06.024", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2012-09-01", "volume": "92", "pages": "329-344" }, { "id": "authors:33ee9-7ky80", "collection": "authors", "collection_id": "33ee9-7ky80", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-132815306", "type": "article", "title": "Water Content, Chlorine and Hydrogen Isotope Compositions of Lunar Apatite", "author": [ { "family_name": "Wang", "given_name": "Y.", "clpid": "Wang-Y" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hsu", "given_name": "W.", "clpid": "Hsu-W" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "The Moon has been thought to have a bulk planetary water content < 1 ppb [1]. Recent ion microprobe analyses have shown that lunar samples contain up to 7000\u00b11000 ppm OR (reported as equivalent H_20) in apatite and 4-46 ppm in\nigneous glass [2-6]. These studies suggest that the mantle\nsources of at least some lunar magmas contain from 64 ppb to\n200 ppm [4-6]. Sharp et al. [6] report an apparently\ncontradictory observation -that ^(37)Cl values of lunar samples vary from -1 to 24%o, with an upper extreme they argue demands devolatilization of anhydrous melts. We examine this issue further through measurements of water content, \u03b4^(37)Cl, and \u03b4D of apatite from lunar meteorites MIL 05035, NWA 2977, and Dhofar 458.", "doi": "10.1111/j.1945-5100.2012.01401_2.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2012-07", "series_number": "S1", "volume": "47", "issue": "S1", "pages": "A397-A397" }, { "id": "authors:ggr7n-9m793", "collection": "authors", "collection_id": "ggr7n-9m793", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20121002-152731528", "type": "article", "title": "Oxygen Isotopes of Al-Rich Chondrules from Unequilibrated Ordinary Chondrites", "author": [ { "family_name": "Hsu", "given_name": "W.", "clpid": "Hsu-W" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Jiang", "given_name": "Y.", "clpid": "Jiang-Y" }, { "family_name": "Wang", "given_name": "Y.", "clpid": "Wang-Y" } ], "abstract": "Al-rich chondrules (ARCs) are a rare constituent of chondrites. They have relatively high bulk Al_2O_3 content (> 10 wt%), which is due to the presence of Al-rich phases, such as plagioclase, spinel, Al-rich glass etc. [1]. ARCs share some chemical and petrologic characteristics with Ca, Al-rich inclusions (CAis), and may represent a genetic link between ferromagnesian chondrules and CAis.", "doi": "10.1111/j.1945-5100.2012.01401_2.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2012-07", "series_number": "S1", "volume": "47", "issue": "S1", "pages": "A196" }, { "id": "authors:pxa4s-n5e23", "collection": "authors", "collection_id": "pxa4s-n5e23", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120417-095344937", "type": "article", "title": "Origin of sulfide replacement textures in lunar breccias. Implications for vapor element transport in the lunar crust", "author": [ { "family_name": "Shearer", "given_name": "C. K.", "clpid": "Shearer-C-K" }, { "family_name": "Burger", "given_name": "P. V.", "clpid": "Burger-P-V" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Papike", "given_name": "J. J.", "clpid": "Papike-J-J" }, { "family_name": "Sutton", "given_name": "S. R.", "clpid": "Sutton-S-R" }, { "family_name": "Atudorei", "given_name": "N.-V.", "clpid": "Atudorei-N-V" } ], "abstract": "Lunar samples 67016,294, 67915,150, and 67016,297 represent clasts of Mg-suite and ferroan anorthosite lithologies that have interacted with a S-rich vapor. Numerous studies have speculated on the composition and source of these \"fluids\", their capability for the transport of vapor-mobilized elements, and the scale and environment under which these types of process occurred. These models all assumed a Moon with a very \"dry\" mantle, crust, and surface. The olivine in these lithologies is partially to totally replaced by troilite and low-Ca pyroxene. The troilite makes up 30\u201354 vol% of the troilite + low-Ca pyroxene pseudomorphs after olivine. Other silicates and oxides in the assemblages have experienced post-magmatic reequilibration (pyroxene exsolution, recrystallization, \"exsolution\" of ilmenite in spinel). The troilite also occurs in veins cross cutting individual phases and metamorphic textures. The sulfide veining and replacement features are restricted to individual clasts and do not cut across the matrix surrounding the clasts, and thus predate the breccia-forming event. The proportion of troilite to low-Ca pyroxene and silicate chemistries indicate that simple reactions (such as olivine + S_2 \u2194 low-Ca pyroxene + troilite + O_2) do not adequately represent the replacement process. The sulfides have compositions that are similar to those found in mare basalts. In particular, the sulfides generally are enriched in Co relative to Ni. Exsolution of Ni\u2013Co\u2013Cu in the sulfides is distinctly different between the breccias and mare basalts and suggests a different cooling or crystallization (melt versus vapor) history. The sulfur isotopic composition of the vein and replacement troilite ranges from approximately \u03b4^(34)S = \u22121.0\u2030 to \u22123.3\u2030.\n\nBased on our observations, it appears that the model suggested by Norman et al. (1995) is the most appropriate for the origin of the troilite veining and troilite\u2013pyroxene pseudomorphs after olivine. Our data add significant definition to this model. This process occurs in the relatively shallow lunar crust on a scale that involves vapor interaction with multiple plutonic lithologies of various ages and compositions. These reactions occur at distinct conditions of fS_2, fO_2, and temperature. The reacting vapor is S-rich, and perhaps low in H. The reduction of the oxides in the clasts was not a product of H-streaming as has been suggested for similar textures in lunar rocks, but more likely related to \"S-streaming\". These vapors had the capability to transport chalcophile\u2013siderophile elements. However, a proportion of the minor elements making up the troilite (Fe, Ni, Co) did come directly from the olivine being replaced. Further, there is evidence to suggest minor mobility of Mg from the olivine pseudomorphs into the adjacent pyroxene. One of the heat sources driving the transport of elements is closely tied to the emplacement of magmas into the shallow lunar crust. These intrusions were either the source for the S or provided heat to remobilized troilite already in the lunar crust. The process that drove the derivation of the S-rich volatiles was instrumental in fractionating the isotopic composition of S. The enrichment of S^32 in the vapor phase may be attributed to either the stable S species during degassing (COS, S_2 and CS_2) or the high-temperature partial breakdown of troilite in the shallow crust.", "doi": "10.1016/j.gca.2011.11.031", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2012-04-15", "volume": "83", "pages": "138-158" }, { "id": "authors:satvk-2tx50", "collection": "authors", "collection_id": "satvk-2tx50", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120523-143303420", "type": "article", "title": "Fine-grained precursors dominate the micrometeorite flux", "author": [ { "family_name": "Taylor", "given_name": "Susan", "clpid": "Taylor-S" }, { "family_name": "Matrajt", "given_name": "Graciela", "clpid": "Matrajt-G" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "We optically classified 5682 micrometeorites (MMs) from the 2000 South Pole collection into textural classes, imaged 2458 of these MMs with a scanning electron microscope, and made 200 elemental and eight isotopic measurements on those with unusual textures or relict phases. As textures provide information on both degree of heating and composition of MMs, we developed textural sequences that illustrate how fine-grained, coarse-grained, and single mineral MMs change with increased heating. We used this information to determine the percentage of matrix dominated to mineral dominated precursor materials (precursors) that produced the MMs. We find that at least 75% of the MMs in the collection derived from fine-grained precursors with compositions similar to CI and CM meteorites and consistent with dynamical models that indicate 85% of the mass influx of small particles to Earth comes from Jupiter family comets. A lower limit for ordinary chondrites is estimated at 2\u20138% based on MMs that contain Na-bearing plagioclase relicts. Less than 1% of the MMs have achondritic compositions, CAI components, or recognizable chondrules. Single mineral MMs often have magnetite zones around their peripheries. We measured their isotopic compositions to determine if the magnetite zones demarcate the volume affected by atmospheric exchange during entry heating. Because we see little gradient in isotopic composition in the olivines, we conclude that the magnetites are a visual marker that allows us to select and analyze areas not affected by atmospheric exchange. Similar magnetite zones are seen in some olivine and pyroxene relict grains contained within MMs.", "doi": "10.1111/j.1945-5100.2011.01292.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2012-04", "series_number": "4", "volume": "47", "issue": "4", "pages": "550-564" }, { "id": "authors:eqf77-cyz13", "collection": "authors", "collection_id": "eqf77-cyz13", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120222-100124696", "type": "article", "title": "Evidence for the extraterrestrial origin of a natural quasicrystal", "author": [ { "family_name": "Bindi", "given_name": "Luca", "orcid": "0000-0003-1168-7306", "clpid": "Bindi-L" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hollister", "given_name": "Lincoln S.", "clpid": "Hollister-L-S" }, { "family_name": "MacPherson", "given_name": "Glenn", "clpid": "MacPherson-G-J" }, { "family_name": "Steinhardt", "given_name": "Paul J.", "clpid": "Steinhardt-P-J" }, { "family_name": "Yao", "given_name": "Nan", "clpid": "Yao-Nan" } ], "abstract": "We present evidence that a rock sample found in the Koryak Mountains in Russia and containing icosahedrite, an icosahedral quasicrystalline phase with composition Al_(63)Cu_(24)Fe_(13), is part of a meteorite, likely formed in the early solar system about 4.5 Gya. The quasicrystal grains are intergrown with diopside, forsterite, stishovite, and additional metallic phases [khatyrkite (CuAl2), cupalite (CuAl), and \u03b2-phase (AlCuFe)]. This assemblage, in turn, is enclosed in a white rind consisting of diopside, hedenbergite, spinel (MgAl_2O_4), nepheline, and forsterite. Particularly notable is a grain of stishovite (from the interior), a tetragonal polymorph of silica that only occurs at ultrahigh pressures (\u226510 Gpa), that contains an inclusion of quasicrystal. An extraterrestrial origin is inferred from secondary ion mass spectrometry ^(18)O/^(16)O and ^(17)O/^(16)O measurements of the pyroxene and olivine intergrown with the metal that show them to have isotopic compositions unlike any terrestrial minerals and instead overlap those of anhydrous phases in carbonaceous chondrite meteorites. The spinel from the white rind has an isotopic composition suggesting that it was part of a calcium-aluminum-rich inclusion similar to those found in CV3 chondrites. The mechanism that produced this exotic assemblage is not yet understood. The assemblage (metallic copper-aluminum alloy) is extremely reduced, and the close association of aluminum (high temperature refractory lithophile) with copper (low temperature chalcophile) is unexpected. Nevertheless, our evidence indicates that quasicrystals can form naturally under astrophysical conditions and remain stable over cosmic timescales, giving unique insights on their existence in nature and stability.", "doi": "10.1073/pnas.1111115109", "pmcid": "PMC3277151", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2012-01-31", "series_number": "5", "volume": "109", "issue": "5", "pages": "1396-1401" }, { "id": "authors:2wddf-eae14", "collection": "authors", "collection_id": "2wddf-eae14", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20120229-135502216", "type": "article", "title": "An oxygen isotope dichotomy in CM2 chondritic carbonates\u2014A SIMS approach", "author": [ { "family_name": "Tyra", "given_name": "M. A.", "clpid": "Tyra-M-A" }, { "family_name": "Farquhar", "given_name": "J.", "clpid": "Farquhar-J" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" } ], "abstract": "We present petrologic and Secondary Ion Mass Spectrometry (SIMS) oxygen isotope analyses of Ca-carbonate within a\ngroup of paired Antarctic CM2 chondrites. The carbonates can be grouped into two isotopically and morphologically distinct populations. Type 1 grains (small matrix grains) possess average \u03b4^(18)O of 33.7 \u00b1 2.3\u2030 (1\u03c3) and average \u0394^(17)O of 0.81\u2030 \u00b1 0.90\u2030 (1\u03c3). Type 2 grains (calcite aggregates) possess distinct oxygen isotopic compositions, average \u03b4^(18)O of 19.4\u2030 \u00b1 1.5\u2030(1\u03c3) and average \u0394^(17)O of 1.98 \u00b1 0.9\u2030(1\u03c3). These differences are interpreted to indicate that the two populations of calcite formed under different conditions at different times. The carbonates have textural features that suggest an extraterrestrial origin. The data presented here fall within error of a previously measured array for carbonates from CM falls (Benedix et al., 2003). The presence of two generations of carbonate suggests carbonate formation in two discrete events on the parent body of these meteorites. The oxygen isotopic data presented here deviate from prior bulk carbonate measurements undertaken for these meteorites. Most likely, this deviation is because bulk carbonate analyses included vein carbonate which formed during terrestrial weathering.", "doi": "10.1016/j.gca.2011.10.003", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2012-01-15", "volume": "77", "pages": "383-395" }, { "id": "authors:wyaxf-knz03", "collection": "authors", "collection_id": "wyaxf-knz03", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20111223-081023439", "type": "article", "title": "Analysis of hydrogen in olivine by SIMS: Evaluation of standards and protocol", "author": [ { "family_name": "Mosenfelder", "given_name": "Jed L.", "clpid": "Mosenfelder-J-L" }, { "family_name": "Le Voyer", "given_name": "Marion", "clpid": "Le-Voyer-M" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Bell", "given_name": "David R.", "clpid": "Bell-D-R" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Asimow", "given_name": "Paul D.", "orcid": "0000-0001-6025-8925", "clpid": "Asimow-P-D" } ], "abstract": "We measured hydrogen concentrations in 12 olivines using secondary ion mass spectrometry (SIMS and NanoSIMS), cross-calibrated against Fourier transform infrared (FTIR) spectroscopy and nuclear reaction analysis (NRA). Five of these samples are routinely used for calibration in other laboratories. We assess the suitability of these olivines as standards based on over 300 SIMS analyses, comprising 22 separate calibrations. Seven olivines with 0\u2013125 ppm H_2O give highly reproducible results; in contrast to previous studies, the data are fit to well-constrained calibration lines with high correlation coefficients (r^2 = 0.98\u20131). However, four kimberlitic megacrysts with 140\u2013245 ppm H_2O sometimes yield ^(16)O^1H/^(30)Si ratios that have low internal precision and can vary by up to a factor of two even in sequential analyses. A possible cause of this behavior is the presence of sub-microscopic inclusions of hydrous minerals, such as serpentine. In most cases, however, we link the anomalous results to the presence of sub-micrometer to micrometer-scale pores (as small as 100 nm), which we imaged using SEM and NanoSIMS. These pores are interpreted to be fluid inclusions containing liquid H_2O, other volatiles (including fluorine), and/or hydrous phase precipitates. Ionization of the contents of the pores contributes variably to the measured ^(16)O^1H, resulting in analyses with erratic depth profiles and corresponding high uncertainties (up to 16%, 2\u03c3_(mean)). After filtering of these analyses using a simple criterion based on the error predicted by Poisson counting statistics, all the data fit well together. Our results imply that the Bell et al. (2003) calibration can be applied accurately to all olivines with IR bands from ~3400\u20133700 cm^(\u22121), without the need for band-specific IR absorption coefficients.", "doi": "10.2138/am.2011.3810", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2011-11", "series_number": "11-12", "volume": "96", "issue": "11-12", "pages": "1725-1741" }, { "id": "authors:kd60x-9hh33", "collection": "authors", "collection_id": "kd60x-9hh33", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130806-144651697", "type": "article", "title": "A dynamic Archean sulfur cycle", "author": [ { "family_name": "Fischer", "given_name": "W. W.", "orcid": "0000-0002-8836-3054", "clpid": "Fischer-W-W" }, { "family_name": "Fike", "given_name": "D. A.", "orcid": "0000-0003-2848-0328", "clpid": "Fike-D-A" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Kirschvink", "given_name": "J. L.", "orcid": "0000-0001-9486-6689", "clpid": "Kirschvink-J-L" }, { "family_name": "Raub", "given_name": "T. D.", "orcid": "0000-0002-7471-0246", "clpid": "Raub-T-D" } ], "abstract": "Many aspects of the Earth's early sulfur cycle, from the origin of mass anomalous fractionations to the scale and\ndegree of biological involvement, remain poorly understood. We have been studying the nature of multiple sulfur isotope\n(^(32)S, ^(33)S, and ^(34)S) signals using a novel combination of scanning high-resolution low-temperature superconductivity\nSQUID microscopy and secondary ion mass spectrometry (SIMS) techniques in a suite of samples from distal slope and\nbasinal environments adjacent to a major Late Archean-age (~2.6-2.52 Ga) carbonate platform. Coupled with petrography,\nthese techniques allow us to interrogate, at the same microscopic scale, the complex history of mineralization in\nsamples containing diverse sulfide-bearing mineral components. Because of a general lack of Archean sulfate\nminerals, we focused our analyses on early diagenetic pyrite nodules, precipitated in surface sediments. This allows us to\nassay fractionations by controlling for isotope mass balance.", "issn": "0026-461X", "publisher": "Mineralogical Society", "publication": "Mineralogical Magazine", "publication_date": "2011-06", "series_number": "3", "volume": "75", "issue": "3", "pages": "850-850" }, { "id": "authors:21q7b-qaj05", "collection": "authors", "collection_id": "21q7b-qaj05", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130807-082106019", "type": "article", "title": "Volatile and major element zonation within melt inclusions: A natural diffusion experiment", "author": [ { "family_name": "Newcombe", "given_name": "M.", "orcid": "0000-0002-8450-768X", "clpid": "Newcombe-M-E" }, { "family_name": "Fabbrizio", "given_name": "A.", "clpid": "Fabbrizio-A" }, { "family_name": "Zhang", "given_name": "Youxue", "orcid": "0000-0002-7439-0086", "clpid": "Zhang-Youxue" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Le Voyer", "given_name": "M.", "clpid": "Le-Voyer-M" }, { "family_name": "Eiler", "given_name": "J.", "clpid": "Eiler-J-M" }, { "family_name": "Saal", "given_name": "A.", "clpid": "Saal-A-E" }, { "family_name": "Stolper", "given_name": "E.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" } ], "abstract": "The diffusivities of volatile elements in silicate melts significantly impact petrological processes [e.g. 1, 2].\nAlthough many studies of volatile diffusion in silicic melts have been undertaken, there have been few studies in basaltic melts [e.g. 3], and most of these have concentrated on the diffusion of only one or two elements in each experiment.", "issn": "0026-461X", "publisher": "Mineralogical Society", "publication": "Mineralogical Magazine", "publication_date": "2011-06", "series_number": "3", "volume": "75", "issue": "3", "pages": "1535-1535" }, { "id": "authors:tcngg-n3854", "collection": "authors", "collection_id": "tcngg-n3854", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130806-135600586", "type": "article", "title": "Silica coatings on young Hawaiian basalts: Constraints on formation mechanism from silicon isotopes", "author": [ { "family_name": "Chemtob", "given_name": "S. M.", "clpid": "Chemtob-S-M" }, { "family_name": "Hurowitz", "given_name": "J. A.", "orcid": "0000-0002-5857-8652", "clpid": "Hurowitz-J-A" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ziegler", "given_name": "K.", "clpid": "Ziegler-K" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" } ], "abstract": "Young basalts from Kilauea, on the big island of Hawai'i, frequently feature visually striking, white, orange and blue\ncoatings, consisting of a 10-50 \u03bcm layer of amorphous silica, capped, in some cases, by a ~1 \u03bcm layer of Fe-Ti oxide [1].\nThe coatings provide an opportunity to study the early onset of acid-sulfate weathering, a process common to many volcanic\nenvironments. Silicon isotopes fractionate with the precipitation of clays and opaline silica, and have been\ndemonstrated to be an indicator of weathering intensity [2,3]. Here we report in situ measurements of \u03b4^(30)_Si of the silica\ncoatings and their implications for coating formation.", "issn": "0026-461X", "publisher": "Mineralogical Society", "publication": "Mineralogical Magazine", "publication_date": "2011-06", "series_number": "3", "volume": "75", "issue": "3", "pages": "649-649" }, { "id": "authors:m243b-v2341", "collection": "authors", "collection_id": "m243b-v2341", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110526-133716941", "type": "article", "title": "Al-Mg systematics of hibonite-bearing Ca,Al-rich inclusions from Ningqiang", "author": [ { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" } ], "abstract": "Hibonite-bearing Ca,Al-rich inclusions (CAIs) usually occur in CM and CH chondrites and possess petrographic and isotopic characteristics distinctive from other typical CAIs. Despite their highly refractory nature, most hibonite-bearing CAIs have little or no ^(26)Mg excess (the decay product of ^(26)Al), but do show wide variations of Ca and Ti isotopic anomalies. A few spinel-hibonite spherules preserve evidence of live ^(26)Al with an inferred ^(26)Al/^(27)Al close to the canonical value. The bimodal distribution of ^(26)Al abundances in hibonite-bearing CAIs has inspired several interpretations regarding the origin of short-lived nuclides and the evolution of the solar nebula. Herein we show that hibonite-bearing CAIs from Ningqiang, an ungrouped carbonaceous chondrite, also provide evidence for a bimodal distribution of ^(26)Al. Two hibonite aggregates and two hibonite-pyroxene spherules show no ^(26)Mg excesses, corresponding to inferred ^(26)Al/^(27)Al < 8 \u00d7 10^(\u22126). Two hibonite-melilite spherules are indistinguishable from each other in terms of chemistry and mineralogy but have different Mg isotopic compositions. Hibonite and melilite in one of them display positive ^(26)Mg excesses (up to 25\u2030) that are correlated with Al/Mg with an inferred ^(26)Al/^(27)Al of (5.5 \u00b1 0.6) \u00d7 10^(\u22125). The other one contains normal Mg isotopes with an inferred ^(26)Al/^(27)Al < 3.4 \u00d7 10^(\u22126). Hibonite in a hibonite-spinel fragment displays large ^(26)Mg excesses (up to 38\u2030) that correlate with Al/Mg, with an inferred ^(26)Al/^(27)Al of (4.5 \u00b1 0.8) \u00d7 10^(\u22125). Prolonged formation duration and thermal alteration of hibonite-bearing CAIs seem to be inconsistent with petrological and isotopic observations of Ningqiang. Our results support the theory of formation of ^(26)Al-free/poor hibonite-bearing CAIs prior to the injection of ^(26)Al into the solar nebula from a nearby stellar source.", "doi": "10.1111/j.1945-5100.2011.01185.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2011-05", "series_number": "5", "volume": "46", "issue": "5", "pages": "719-728" }, { "id": "authors:9ywx4-s0v43", "collection": "authors", "collection_id": "9ywx4-s0v43", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110329-153322551", "type": "article", "title": "Geochemistry and origin of tektites from Guilin of Guangxi,\n Guangdong and Hainan", "author": [ { "family_name": "Lin", "given_name": "Su", "clpid": "Lin-Su" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" } ], "abstract": "Six tektites from Guilin of Guangxi, Hainan, and Guangdong were analyzed for the abundances of major elements and 27 trace elements. All samples are splash-form tektites and have SiO_2 contents ranging from 73.1wt% to 76.0wt% (74.6wt% on average). The chemical compositions, except Cr and Ni, of tektites from different areas, are similar. Guangdong tektite shows enrichments of Ni and Cr contents by a factor of 3, and has slightly higher MgO and FeO than Hainan and Guilin tektites. It indicates that the tektites were formed by mixing several target rocks. The major and trace element concentrations of southern China tektites closely resemble previously reported data for average splash-form and Muong Nong-type indochinites, indicating that they have the same source. (La/Lu)_CI (7.99), Zr/Hf (35.45 on average), Ba/Rb (3.59 on average), and the rare earth element (REE) contents of tektites are similar to those of typical post Archean upper crustal rocks. This study suggests that the best fit for the target source of southern China tektites could be a combination of 41% shale, 2% sandstone, 20% greywacke, and 37% quartzite.", "doi": "10.1007/s11430-010-4146-1", "issn": "1674-7313", "publisher": "Springer", "publication": "Science China Earth Sciences", "publication_date": "2011-03", "series_number": "3", "volume": "54", "issue": "3", "pages": "349-358" }, { "id": "authors:bmcdq-thw35", "collection": "authors", "collection_id": "bmcdq-thw35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100928-135928624", "type": "article", "title": "Neutron-rich Chromium Isotope Anomalies in Supernova Nanoparticles", "author": [ { "family_name": "Dauphas", "given_name": "N.", "orcid": "0000-0002-1330-2038", "clpid": "Dauphas-N" }, { "family_name": "Remusat", "given_name": "L.", "clpid": "Remusat-L" }, { "family_name": "Chen", "given_name": "J. H.", "clpid": "Chen-J-H" }, { "family_name": "Roskosz", "given_name": "M.", "clpid": "Roskosz-M" }, { "family_name": "Papanastassiou", "given_name": "D. A.", "clpid": "Papanastassiou-D-A" }, { "family_name": "Stodolna", "given_name": "J.", "clpid": "Stodolna-J" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "Neutron-rich isotopes with masses near that of iron are produced in Type Ia and II supernovae (SNeIa and SNeII). Traces of such nucleosynthesis are found in primitive meteorites in the form of variations in the isotopic abundance of ^(54)Cr, the most neutron-rich stable isotope of chromium. The hosts of these isotopic anomalies must be presolar grains that condensed in the outflows of SNe, offering the opportunity to study the nucleosynthesis of iron-peak nuclei in ways that complement spectroscopic observations and can inform models of stellar evolution. However, despite almost two decades of extensive search, the carrier of ^(54)Cr anomalies is still unknown, presumably because it is fine grained and is chemically labile. Here, we identify in the primitive meteorite Orgueil the carrier of ^(54)Cr anomalies as nanoparticles (<100 nm), most likely spinels that show large enrichments in ^(54)Cr relative to solar composition ((54)^Cr/^(52)Cr ratio >3.6 \u00d7 solar). Such large enrichments in ^(54)Cr can only be produced in SNe. The mineralogy of the grains supports condensation in the O/Ne-O/C zones of an SNII, although a Type Ia origin cannot be excluded. We suggest that planetary materials incorporated different amounts of these nanoparticles, possibly due to late injection by a nearby SN that also delivered ^(26)Al and ^(60)Fe to the solar system. This idea explains why the relative abundance of ^(54)Cr and other neutron-rich isotopes vary between planets and meteorites. We anticipate that future isotopic studies of the grains identified here will shed new light on the birth of the solar system and the conditions in SNe.", "doi": "10.1088/0004-637X/720/2/1577", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2010-09-10", "series_number": "2", "volume": "720", "issue": "2", "pages": "1577-1591" }, { "id": "authors:bxgjv-vxh50", "collection": "authors", "collection_id": "bxgjv-vxh50", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100811-091146314", "type": "article", "title": "Lunar apatite with terrestrial volatile abundances", "author": [ { "family_name": "Boyce", "given_name": "Jeremy W.", "clpid": "Boyce-J-W" }, { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Stolper", "given_name": "Edward M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" }, { "family_name": "Taylor", "given_name": "Lawrence A.", "clpid": "Taylor-L-A" } ], "abstract": "The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO_2-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained ~1,600 parts per million H_2O and ~3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought.", "doi": "10.1038/nature09274", "issn": "0028-0836", "publisher": "Nature Publishing Group", "publication": "Nature", "publication_date": "2010-07-22", "series_number": "7305", "volume": "466", "issue": "7305", "pages": "466-469" }, { "id": "authors:xq98c-9f706", "collection": "authors", "collection_id": "xq98c-9f706", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130129-073104997", "type": "article", "title": "Solar Wind Abundances of C and O", "author": [ { "family_name": "Heber", "given_name": "V. S.", "clpid": "Heber-V-S" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Jurewicz", "given_name": "A. J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-A-J-G" }, { "family_name": "Kallio", "given_name": "A. P.", "clpid": "Kallio-A-P-A" }, { "family_name": "Olinger", "given_name": "C.", "orcid": "0000-0002-9509-6345", "clpid": "Olinger-C-T" }, { "family_name": "Woolum", "given_name": "D. S.", "clpid": "Woolum-D-S" }, { "family_name": "McKeegan", "given_name": "K. D.", "clpid": "McKeegan-K-D" }, { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" } ], "abstract": "Quantitative understanding of solar wind (SW) elemental fractionation is required to improve knowledge of the solar nebula abundances from Genesis samples, in particular abundances of volatile elements, depleted in CI chondrites. Ratios of elements with low and high first ionization potential (FIP) in the solar wind, e.g., Fe/He, are higher than photospheric abundances. C, O, and N have intermediate FIP and are thus critical as to whether this fractionation is stepwise or gradual as a function of FIP.", "doi": "10.1111/j.1945-5100.2010.01051.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2010-07", "series_number": "S1", "volume": "45", "issue": "S1", "pages": "A78" }, { "id": "authors:crb4v-1pg61", "collection": "authors", "collection_id": "crb4v-1pg61", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130731-080018704", "type": "article", "title": "Supernova Nanoparticles are the Carriers of ^(54)Cr Anomalies in Planetary Materials", "author": [ { "family_name": "Dauphas", "given_name": "N.", "orcid": "0000-0002-1330-2038", "clpid": "Dauphas-N" }, { "family_name": "Remusat", "given_name": "L.", "clpid": "Remusat-L" }, { "family_name": "Chen", "given_name": "J. H.", "clpid": "Chen-J-H" }, { "family_name": "Roskosz", "given_name": "M.", "clpid": "Roskosz-M" }, { "family_name": "Papanastassiou", "given_name": "D. A.", "clpid": "Papanastassiou-D-A" }, { "family_name": "Stodolna", "given_name": "J.", "clpid": "Stodolna-J" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "Acid leachates and residues of primitive meteorites have revealed\nlarge variations in ^(54)Cr relative to terrestrial composition [1\u20139]. Despite two decades of extensive search, the nature of the carrier of ^(54)Cr excesses is still uncertain. Ion probes offer the opportunity to address directly this question by measuring ^(54)Cr/^(52)Cr ratios in individual grains [10\u201313].", "doi": "10.1111/j.1945-5100.2010.01051.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2010-07", "series_number": "S1", "volume": "45", "issue": "S1", "pages": "A42" }, { "id": "authors:y3hbs-5qx07", "collection": "authors", "collection_id": "y3hbs-5qx07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100607-120524366", "type": "article", "title": "Accretion and Preservation of D-rich Organic Particles in Carbonaceous Chondrites: Evidence for Important Transport in the Early Solar System Nebula", "author": [ { "family_name": "Remusat", "given_name": "L.", "clpid": "Remusat-L" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Y.", "clpid": "Wang-Y" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "We have acquired NanoSIMS images of the matrices of CI, CM, and CR carbonaceous chondrites to study, in situ, the organic matter trapped during the formation of their parent bodies. D/H ratio images reveal the occurrence of D-rich hot spots, constituting isolated organic particles. Not all the organic particles are D-rich hot spots, indicating that at least two kinds of organic particles have been accreted in the parent bodies. Ratio profiles through D-rich hot spots indicate that no significant self-diffusion of deuterium occurs between the D-rich organic matter and the depleted hydrous minerals that are surrounding them. This is not the result of a physical shielding by any constituent of the chondrites. Ab initio calculations indicate that it cannot be explained by isotopic equilibrium. Then it appears that the organic matter that is extremely enriched in D does not exchange with the hydrous minerals, or this exchange is so slow that it is not significant over the 4.5 billion year history on the parent body. If we consider that the D-rich hot spots are the result of an exposure to intense irradiation, then it appears that carbonaceous chondrites accreted organic particles that have been brought to different regions of the solar nebula. This is likely the result of important radial and vertical transport in the early solar system.", "doi": "10.1088/0004-637X/713/2/1048", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2010-04-20", "series_number": "2", "volume": "713", "issue": "2", "pages": "1048-1058" }, { "id": "authors:203kh-r4172", "collection": "authors", "collection_id": "203kh-r4172", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20100629-090504506", "type": "article", "title": "Origin of a metamorphosed lithic clast in CM chondrite Grove Mountains 021536", "author": [ { "family_name": "Zhang", "given_name": "Aicheng", "clpid": "Zhang-Aicheng" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Liu", "given_name": "Yang", "clpid": "Liu-Yang-JPL" }, { "family_name": "Taylor", "given_name": "Lawrence A.", "clpid": "Taylor-L-A" } ], "abstract": "A metamorphosed lithic clast was discovered in the CM chondrite Grove Mountains 021536, which was collected in the Antarctica by the Chinese Antarctic Research Exploration team. The lithic clast is composed mainly of Fe-rich olivine (Fo62) with minor diopside (Fs_(9.7\u201311.1)Wo_(48.3\u201351.6)), plagioclase (An_(43\u201346.5)), nepheline, merrillite, Al-rich chromite (21.8 wt% Al_2O_3; 4.43 wt% TiO_2), and pentlandite. \u0394^(17)O values of olivine in the lithic clast vary from \u22123.9\u2030 to \u22120.8\u2030. Mineral compositions and oxygen isotopic compositions of olivine suggest that the lithic clast has an exotic source different from the CM chondrite parent body. The clast could be derived from strong thermal metamorphism of pre-existing chondrule that has experienced low-temperature anhydrous alteration. The lithic clast is similar in mineral assemblage and chemistry to a few clasts observed in oxidized CV3 chondrites (Mokoia and Yamato-86009) and might have been derived from the interior of the primitive CV asteroid. The apparent lack of hydration in the lithic clast indicates that the clast accreted into the CM chondrite after hydration of the CM components.", "doi": "10.1111/j.1945-5100.2010.01020.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2010-02", "series_number": "2", "volume": "45", "issue": "2", "pages": "238-245" }, { "id": "authors:42vcs-r0544", "collection": "authors", "collection_id": "42vcs-r0544", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130730-080729085", "type": "article", "title": "Chemical and Isotopic Diversity of Organic Particles in Chondrites: Parent Body vs. Nebular Processes", "author": [ { "family_name": "Remusat", "given_name": "L.", "clpid": "Remusat-L" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "Insoluble organic matter (IOM), the main organic constituent in chondrites, has been extensively studied after HF/HCl isolation techniques. Bulk isotopic compositions and elemental ratios show variations between chondrite groups, whereas they are quite homogeneous within each class [1]. Recent isotopic measurements by ion probes have revealed that IOM is heterogeneous at the sub-micron scale [2,3]. Does this heterogeneity reflect parent body evolution or reactions in the gas phase prior to accretion? \n\nTo answer this question, we have studied in situ organic matter in Orgueil (CI), Tagish Lake, Murchison (CM), Cold Bokkeveld (CM), Allende (CV), Renazzo (CR) and Chainpur (LL) by NanoSIMS imaging. We have determined D/H ratios and chemical composition (C, H and N contents) of organic particles in the matrices of these meteorites.", "doi": "10.1111/j.1945-5100.2009.tb01099.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2009-07", "series_number": "S7", "volume": "44", "issue": "S7", "pages": "A174" }, { "id": "authors:nz7s2-bxn68", "collection": "authors", "collection_id": "nz7s2-bxn68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130129-111130154", "type": "article", "title": "Preliminary Nanosims Analysis of Carbon Isotope of Carbonates in Calcium-Aluminum-Rich Inclusions", "author": [ { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Paque", "given_name": "J. M.", "orcid": "0000-0003-0554-7876", "clpid": "Paque-J-M" }, { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "Carbonate minerals observed in primitive meteorites are products of either terrestrial weathering or aqueous alteration in the early solar system. Most of the carbonate minerals in carbonaceous chondrites occur primarily as isolated grains in matrix, as crosscutting veins, or as replacement minerals in chondrules [e.g., 1, 2]. A few calcium-aluminum-rich inclusions (CAIs) have been reported containing carbonate minerals as well [2, 3]. The C and O isotopes of carbonates in carbonaceous chondrites, mostly measured by stepwise extraction of bulk samples with phosphoric acid [4\u20137], are largely distinctive from those of terrestrial carbonates, whereas textural and petrographic evidence indicates that some carbonates in primitive meteorites are terrestrial in origin [2]. This study attempts to investigate from the aspect of C isotope the origin of rare carbonate minerals in some CAIs. If of extraterrestrial origin, carbonates in CAIs can provide important information and constraints on the ubiquitous aqueous alteration process in the early solar system.", "doi": "10.1111/j.1945-5100.2009.tb01099.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2009-07", "series_number": "S7", "volume": "44", "issue": "S7", "pages": "A82" }, { "id": "authors:166qe-jpp59", "collection": "authors", "collection_id": "166qe-jpp59", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130730-080026323", "type": "article", "title": "NanoSIMS imaging of insoluble organic matter in ordinary chondrites: Comparison with carbonaceous chondrites", "author": [ { "family_name": "Remusat", "given_name": "L.", "clpid": "Remusat-L" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" } ], "abstract": "The insoluble organic matter (IOM) is known to be enriched in deuterium in carbonaceous chondrites (CC) and ordinary chondrites (OC) [1]. Moreover, the isotopic composition of the IOM in CI and CM chondrites is heterogeneous at the molecular scale [2] and the micron scale [3]. In Orgueil IOM, the occurrence of D-rich hot spots is related to the heterogeneous distribution of organic radicals caracterised by a D/H ratio of 1.5% [4]. The D-isotopic enrichment is related to ion-molecule like reactions - taking place in the outer areas of the protosolar nebula or the interestellar space - that have affected the IOM before accretion on the parent body. The isotopic variations of IOMs in various types of chondrites are complex and have been related to parent body processes [1], if we assume a comon precursor to the IOM in all the parent bodies. However, this hypothesis seems inconsistent with in situ imaging of organic matter in the matrices of carbonaceous chondrites, which reveals that it exists at least two kinds of organic matter [5].", "doi": "10.1016/j.gca.2009.05.014", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2009-06", "series_number": "13", "volume": "73", "issue": "13", "pages": "A1089" }, { "id": "authors:71s8q-nbd85", "collection": "authors", "collection_id": "71s8q-nbd85", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130729-100558629", "type": "article", "title": "Ultrasteep composition gradients within ankerite grains from regionally metamorphosed marls", "author": [ { "family_name": "Ferry", "given_name": "J. M.", "clpid": "Ferry-J-M" }, { "family_name": "Stubbs", "given_name": "J. E.", "clpid": "Stubbs-J-E" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "Ankerite (Ank) grains frequently contain cores of almost\npure dolomite (Dol) in the garnet zone and at lower grades of\nthree areally extensive stratigraphic units from both Buchan\nand Barrovian terrains in northern New England, USA. Dol\ncores and Ank rims have Fe/(Fe+Mg) in the range 0.006-0.011\nand 0.16-0.23, respectively. Ank grains with dolomite cores\nhave many features closely analogous to K-feldspar rims\naround albite cores produced experimentally by incomplete\nhydrothermal reaction between albite and KCl solution [1]: (a)\nAnk-Dol contacts are irregular but sharp at the micron scale,\n(b) The orientations of the Ank and Dol crystal lattices are\nidentical, (c) Fe/(Fe+Mg) of Ank is often slightly greater at the\nAnk-Dol contact than further away, (d) The Ank-Dol contact\nis often decorated with open pores. Based on these similarities,\nAnk appears to have replaced detrital Dol by a dissolution-reprecipitation\nmechanism during diagnesis or very low grade\nregional metamorphism.", "doi": "10.1016/j.gca.2009.05.005", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2009-06", "series_number": "13", "volume": "73", "issue": "13", "pages": "A372" }, { "id": "authors:x0e47-35j37", "collection": "authors", "collection_id": "x0e47-35j37", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130726-092553235", "type": "article", "title": "New capabilities for small-scale and high-precision SIMS analyses", "author": [ { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Adkins", "given_name": "Jess F.", "orcid": "0000-0002-3174-5190", "clpid": "Adkins-J-F" }, { "family_name": "Chapman", "given_name": "Alan", "clpid": "Chapman-A-D" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hofmann", "given_name": "Amy", "clpid": "Hoffmann-A" }, { "family_name": "Ferry", "given_name": "John", "clpid": "Ferry-J-M" } ], "abstract": "Secondary ion mass spectrometry (SIMS) has wide application for in situ geochronology, trace element and isotope analysis. Despite the strengths of SIMS techniques, their usefulness has been limited for many problems by the relatively coarse scale of analysis (~10-30 \u00b5m), and poor precision for element abundance ratios (~1-10 %, relative). \n\nThree recent innovations in SIMS instrumentation have improved capabilities in both regards, creating opportunities for new kinds of applications: (1) The NanoSIMS provides a reduced primary beam size (typically 100-300 nm; as small as 10's of nm). A conventional SIMS instrument equipped with a Gallium source can achieve similar resolutions, though at the cost of significantly reduced sensitivity. (2) The NanoSIMS is also the first ion microprobe capable of simultaneous detection of elements differing greatly in mass (up to a factor of 22; e.g., ^(12)C and ^(238)U). This allows for multi-collection of most element ratios, much as isotope ratio multi-collection is done on lower-dispersion mass spectrometers. (3) The ims-7f Geo provides a 'pseudo multi-collection' capability. This is intended as a poor-man's instrument for high-precision isotope ratio analysis, but also permits element ratio measurements at greater than normal speed and precision.", "doi": "10.1016/j.gca.2009.05.004", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2009-06", "series_number": "13", "volume": "73", "issue": "13", "pages": "A321" }, { "id": "authors:7e1xx-hm460", "collection": "authors", "collection_id": "7e1xx-hm460", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130710-110455167", "type": "book_section", "title": "In-situ Discovery of a Cluster of Refractory Grains in an Allende Ferromagnesian Chondrule", "author": [ { "family_name": "Ma", "given_name": "C.", "orcid": "0000-0002-1828-7033", "clpid": "Ma-Chi-Geology" }, { "family_name": "Beckett", "given_name": "J. R.", "clpid": "Beckett-J-R" }, { "family_name": "Rossman", "given_name": "G. R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Connolly", "given_name": "H. C., Jr.", "clpid": "Connolly-H-C-Jr" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Hofmann", "given_name": "A. E.", "clpid": "Hofmann-A-E" } ], "abstract": "During our nano-mineralogy investigation of the Allende meteorite, we discovered a unique corundum-rich cluster of irregular micrometer-sized refractory grains in a type IA chondrule. The presence of relatively oxidized (rutile) and highly reduced (a new mineral Ti_2O_3, khamrabaevite) phases in the same cluster reflects distinctly different environments prior to incorporation of the cluster into the chondrule. To our knowledge, this is the first occurrence of such a cluster. Investigation of phases that are clearly exotic to the host chondrule and may predate its formation can provide not only important constraints on the materials present when chondrules formed and the enviroments within or outside the Protoplanetary disk, but also on the chondrule formation event. Herein we report our prelimary results on the mineralogy of these grains and the overall petrology of their host chondrule.", "publisher": "Lunar and Planetary Institute", "publication_date": "2009-03" }, { "id": "authors:vzvpj-q7v96", "collection": "authors", "collection_id": "vzvpj-q7v96", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:PUTnl08", "type": "article", "title": "Secondary ion mass spectrometry of vapor\u2212liquid\u2212solid grown, Au-catalyzed, Si wires", "author": [ { "family_name": "Putnam", "given_name": "Morgan C.", "clpid": "Putnam-M-C" }, { "family_name": "Filler", "given_name": "Michael A.", "orcid": "0000-0003-4239-8558", "clpid": "Filler-M-A" }, { "family_name": "Kayes", "given_name": "Brendan M.", "clpid": "Kayes-B-M" }, { "family_name": "Kelzenberg", "given_name": "Michael D.", "orcid": "0000-0002-6249-2827", "clpid": "Kelzenberg-M-D" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Lewis", "given_name": "Nathan S.", "orcid": "0000-0001-5245-0538", "clpid": "Lewis-N-S" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Atwater", "given_name": "Harry A.", "orcid": "0000-0001-9435-0201", "clpid": "Atwater-H-A" } ], "abstract": "Knowledge of the catalyst concentration within vapor-liquid-solid (VLS) grown semiconductor wires is needed in order to assess potential limits to electrical and optical device performance imposed by the VLS growth mechanism. We report herein the use of secondary ion mass spectrometry to characterize the Au catalyst concentration within individual, VLS-grown, Si wires. For Si wires grown by chemical vapor deposition from SiCl_4 at 1000 \u00b0C, an upper limit on the bulk Au concentration was observed to be 1.7 x 10^16 atoms/cm^3, similar to the thermodynamic equilibrium concentration at the growth temperature. However, a higher concentration of Au was observed on the sidewalls of the wires.", "doi": "10.1021/nl801234y", "issn": "1530-6984", "publisher": "American Chemical Society", "publication": "Nano Letters", "publication_date": "2008-10", "series_number": "10", "volume": "8", "issue": "10", "pages": "3109-3113" }, { "id": "authors:9j94f-zhw39", "collection": "authors", "collection_id": "9j94f-zhw39", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130726-083225752", "type": "article", "title": "Relationships between \u03bcm-scale melt inclusions and oscillatory trace element zoning in olivine", "author": [ { "family_name": "Mansfield", "given_name": "F. C.", "clpid": "Mansfield-F-C" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Stolper", "given_name": "E. M.", "orcid": "0000-0001-8008-8804", "clpid": "Stolper-E-M" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "Oscillatory zoning of trace elements P, Cr and Al in\notherwise unzoned magmatic olivines may preserve\ninformation on early crystallisation histories [1, 2], because\nthe higher diffusivities of Mg, Fe, Mn, Ca and Ni inhibit\npreservation of such clues in the major and minor elements.\nConcentrations of P in trace-element-rich bands exceed\nexpected equilibrium values, and similar enrichment bands are\nobserved in olivines grown experimentally at constant cooling\nrate [2]; thus, it seems likely that this phenomenon in natural\nolivine reflects local kinetic processes during crystal growth\nrather than oscillations in magma temperature or bulk\ncomposition.", "doi": "10.1016/j.gca.2008.05.016", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2008-07", "series_number": "12", "volume": "72", "issue": "12", "pages": "A590" }, { "id": "authors:5hq1r-s5b89", "collection": "authors", "collection_id": "5hq1r-s5b89", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650032000.18", "type": "article", "title": "Chemical and oxygen isotopic compositions of accretionary rim and matrix olivine in CV chondrites: Constraints on the evolution of nebular dust", "author": [ { "family_name": "Cosarinsky", "given_name": "Mariana", "clpid": "Cosarinsky-Mariana" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "MacPherson", "given_name": "Glenn J.", "clpid": "MacPherson-Glenn-J" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Krot", "given_name": "Alexander N.", "orcid": "0000-0002-2278-8519", "clpid": "Krot-Alexander-N" } ], "abstract": "A correlation of petrography, mineral chemistry and in situ oxygen isotopic compositions of fine-grained olivine from the matrix and of fine- and coarse-grained olivine from accretionary rims around Ca\u2013Al-rich inclusions (CAIs) and chondrules in CV chondrites is used here to constrain the processes that occurred in the solar nebula and on the CV parent asteroid. The accretionary rims around Leoville, Vigarano, and Allende CAIs exhibit a layered structure: the inner layer consists of coarse-grained, forsteritic and \u00b9\u2076O-rich olivine (Fa\u2081\u208b\u2084\u2080 and \u0394\u00b9\u2077O = \u221224\u2030 to \u22125\u2030; the higher values are always found in the outer part of the layer and only in the most porous meteorites), whereas the middle and the outer layers contain finer-grained olivines that are more fayalitic and \u00b9\u2076O-depleted (Fa\u2081\u2085\u208b\u2085\u2080 and \u0394\u00b9\u2077O = \u221218\u2030 to +1\u2030). The CV matrices and accretionary rims around chondrules have olivine grains of textures, chemical and isotopic compositions similar to those in the outer layers of accretionary rims around CAIs. There is a correlation between local sample porosity and olivine chemical and isotopic compositions: the more compact regions (the inner accretionary rim layer) have the most MgO- and \u00b9\u2076O-rich compositions, whereas the more porous regions (outer rim layers around CAIs, accretionary rims around chondrules, and matrices) have the most MgO- and \u00b9\u2076O-poor compositions. In addition, there is a negative correlation of olivine grain size with fayalite contents and \u0394\u00b9\u2077O values. However, not all fine-grained olivines are FeO-rich and \u00b9\u2076O-poor; some small (<1 \u03bcm in Leoville and 5\u201310 \u03bcm in Vigarano and Allende) ferrous (Fa_(>20)) olivine grains in the outer layers of the CAI accretionary rims and in the matrix show significant enrichments in \u00b9\u2076O (\u0394\u00b9\u2077O = \u221220\u2030 to \u221210\u2030). We infer that the inner layer of the accretionary rims around CAIs and, at least, some olivine grains in the finer portions of accretionary rims and CV matrices formed in an \u00b9\u2076O-rich gaseous reservoir, probably in the CAI-forming region. Grains in the outer layers of the CAI accretionary rims and in the rims around chondrules as well as matrix may have also originated as \u00b9\u2076O-rich olivine. However, these olivines must have exchanged O isotopes to variable extents in the presence of an \u00b9\u2076O-poor reservoir, possibly the nebular gas in the chondrule-forming region(s) and/or fluids in the parent body. The observed trend in isotopic compositions may arise from mixtures of \u00b9\u2076O-rich forsterites with grain overgrowths or newly formed grains of \u00b9\u2076O-poor fayalitic olivines formed during parent body metamorphism. However, the observed correlations of chemical and isotopic compositions of olivine with grain size and local porosity of the host meteorite suggest that olivine accreted as a single population of \u00b9\u2076O-rich forsterite and subsequently exchanged Fe\u2013Mg and O isotopes in situ in the presence of aqueous solutions (i.e., fluid-assisted thermal metamorphism).", "doi": "10.1016/j.gca.2007.12.025", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2008-04-01", "series_number": "7", "volume": "72", "issue": "7", "pages": "1887-1913" }, { "id": "authors:gns65-qza81", "collection": "authors", "collection_id": "gns65-qza81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141022-114335915", "type": "article", "title": "Assessment of shock effects on amphibole water contents and hydrogen isotope compositions: 2. Kaersutitic amphibole experiments", "author": [ { "family_name": "Minitti", "given_name": "Michelle E.", "orcid": "0000-0003-4715-4544", "clpid": "Minitti-M-E" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" }, { "family_name": "Dyar", "given_name": "M. Darby", "orcid": "0000-0003-4272-793X", "clpid": "Dyar-M-D" }, { "family_name": "Ahrens", "given_name": "Thomas J.", "clpid": "Ahrens-T-J" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Luo", "given_name": "Sheng-Nian", "clpid": "Luo-Sheng-Nian" } ], "abstract": "To constrain the influence of impact shock on water and hydrogen isotope signatures of Martian meteorite kaersutites, we conducted shock recovery experiments on three terrestrial kaersutite crystals. Homogeneous impact shock to 32 GPa, commensurate with shock levels experienced by Martian meteorite kaersutites, led to increases in kaersutite water contents (\u0394H_2O = 0.25\u20130.89 wt.%), decreases in Fe^3+/\u03a3Fe (4\u201320%), and enrichments in hydrogen isotope composition (\u0394D = + 66 to + 87\u2030) relative to pre-shock values. The latter values represent the largest shock-induced hydrogen isotope fractionations measured to date. These observations are explained most completely by a two-step shock process. First, shock-induced devolatilization led to hydrogen isotope enrichment through preferential loss of H relative to D. Second, reaction of the kaersutite with the ambient atmosphere led to increased water contents and reduced Fe. Fe reduction and water addition via the reaction Fe^2+ + OH^\u2212 \u2194 Fe^3+ + O_2\u2212 + \u00bdH_2 explain the Fe^3+/\u03a3Fe data and some of the water data. Further water addition mechanisms (irreversible adsorption, shock implantation) are necessary to fully explain the increased water contents. Addition of water from the terrestrial atmosphere, which is isotopically light relative to the experimental kaersutite compositions, means the measured hydrogen isotope enrichments are likely minima. The measured (minimum) levels of hydrogen isotope enrichment are relevant to the hydrogen isotope variability within and among Martian kaersutites, but are minor relative to their absolute \u03b4D values. Alternatively, addition of water from the enriched Martian atmosphere could explain both Martian kaersutite hydrogen isotope variability and absolute \u03b4D values. However, the low Martian kaersutite water contents leave little room for significant water addition. The importance of the ambient atmosphere to the outcome of the shock experiments makes it difficult to translate our results to Mars given the unknown influence of its more tenuous atmosphere on the processes observed in the experiments. Our results suggest that shock is a feasible mechanism for influencing Martian kaersutite water contents and hydrogen isotope compositions but that its complex signature precludes precise determination of that influence.", "doi": "10.1016/j.epsl.2007.11.012", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2008-02-28", "series_number": "3-4", "volume": "266", "issue": "3-4", "pages": "288-302" }, { "id": "authors:8zw5y-qga04", "collection": "authors", "collection_id": "8zw5y-qga04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650044000.20", "type": "article", "title": "\u2076\u2070Fe\u2013\u2076\u2070Ni and \u2075\u00b3Mn\u2013\u2075\u00b3Cr isotopic systems in sulfides from unequilibrated enstatite chondrites", "author": [ { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Huss", "given_name": "Gary R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-Gary-R" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" } ], "abstract": "In situ measurements of \u2076\u2070Fe\u2013\u2076\u2070Ni and \u2075\u00b3Mn\u2013\u2075\u00b3Cr isotopic systems with an ion microprobe have been carried out for sulfide assemblages from unequilibrated enstatite chondrites (UECs). Evidence for the initial presence of \u2076\u2070Fe has been observed in nine sulfide inclusions from three UECs: ALHA77295, MAC88136, and Qingzhen. The inferred initial (\u2076\u2070Fe/56Fe) [(\u2076\u2070Fe/\u2075\u2076Fe)0] ratios show a large variation range, from \u223c2 \u00d7 10\u207b\u2077 to \u223c2 \u00d7 10\u207b\u2070. The sulfide inclusions with high Fe/Ni ratios yield (\u2076\u2070Fe/\u2075\u2076Fe)\u2080 ratios of \u223c(2\u20137) \u00d7 10\u207b\u2077, similar to most of the (\u2076\u2070Fe/\u2075\u2076Fe)\u2080 values of troilite and pyroxene observed in unequilibrated ordinary chondrites (UOCs). Inclusions with high inferred (\u2076\u2070Fe/\u2075\u2076Fe)\u2080 ratios (\u223c1\u20132 \u00d7 10\u207b\u2076) have low Fe/Ni ratios and the magnitude of the 60Ni excesses is similar in two MAC88136 assemblages in spite of a difference of a factor of two in their Fe/Ni ratios. The inferred high (\u2076\u2070Fe/\u2075\u2076Fe)\u2080 ratios were probably the result of Fe\u2013Ni re-distribution in the sulfides during later alteration processes. \n\nThe \u2075\u00b3Mn\u2013\u2075\u00b3Cr system was measured in five of the sulfide assemblages that were examined for their \u2076\u2070Fe\u2013\u2076\u2070Ni systematics. The \u2075\u00b3Mn\u2013\u2075\u00b3Cr isochrons yielded variable initial (\u2075\u00b3Mn/\u2075\u2075Mn) [(\u2075\u00b3Mn/\u2075\u2075Mn)\u2080] ratios from \u223c(2\u20137) \u00d7 10\u207b\u2077. There is no obvious correlation between the (\u2076\u2070Fe/\u2076\u2070Fe)0 and (\u2075\u00b3Mn/\u2075\u2075Mn)\u2080 ratios. The variable \u2075\u00b3Mn\u2013\u2075\u00b3Cr isochrons probably also indicate later disturbance to the isotopic systems in these sulfides. Even though no chronological information can be extracted from the 60Fe\u201360Ni and \u2075\u00b3Mn\u2013\u2075\u00b3Cr systems in these UEC sulfides, our results indicate that \u2076\u2070Fe was present in the enstatite chondrite formation region of the early Solar System.", "doi": "10.1016/j.gca.2007.06.032", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2007-08-15", "series_number": "16", "volume": "71", "issue": "16", "pages": "4082-4091" }, { "id": "authors:xwn8f-abh34", "collection": "authors", "collection_id": "xwn8f-abh34", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130211-144010988", "type": "article", "title": "Micron-scale resolution of sulfur cycling in a microbial mat", "author": [ { "family_name": "Fike", "given_name": "David", "orcid": "0000-0003-2848-0328", "clpid": "Fike-D-A" }, { "family_name": "Ussler", "given_name": "William", "clpid": "Ussler-W-III" }, { "family_name": "Eiler", "given_name": "John", "clpid": "Eiler-J-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Orphan", "given_name": "Victoria", "orcid": "0000-0002-5374-6178", "clpid": "Orphan-V-J" } ], "abstract": "Microbial mats consist of finely laminated layers of\ndiverse microbial communities. Mat organization is thought\nto result from strong spatial gradients in light intensity and\nredox in the uppermost few millimeters Optical examination\nreveals microbial laminations on scales between 5mm and\n5um throughout the thickness of the microbial mat. However,\nsuch fine laminations at depth have usually been regarded as a\n'relict architecture' inherited from an older mat surface. To\nfurther our understanding of microbial processes within this\nlaminated architecture, we have investigated sulfur cycling (as\nrecorded by sulfide production) within a benthic microbial\nmat.", "doi": "10.1016/j.gca.2007.06.015", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2007-08", "series_number": "15", "volume": "71", "issue": "15", "pages": "A278" }, { "id": "authors:m95da-2zx17", "collection": "authors", "collection_id": "m95da-2zx17", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130130-151743924", "type": "article", "title": "SIMS results for solar wind elemental abundances from genesis collectors", "author": [ { "family_name": "Jurewicz", "given_name": "A. J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-A-J-G" }, { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Woolum", "given_name": "D. S.", "clpid": "Woolum-D-S" }, { "family_name": "McKeegan", "given_name": "K. D.", "clpid": "McKeegan-K-D" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hervig", "given_name": "R.", "clpid": "Hervig-R-L" } ], "abstract": "Solar wind elemental abundances are a major Genesis science objective. Spacecraft studies have shown that elements with first ionization potential (FIP) > 9 eV are fractionated relative to those with lower FIP compared with the solar photosphere; however, among elements with FIP < 9eV (which make up most of the terrestrial planets) there is no evidence of fractionation. A major goal of Genesis is to provide a higher precision test of the lack of fractionation for FIP < 9eV.", "doi": "10.1111/j.1945-5100.2007.tb00601.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2007-08", "series_number": "S8", "volume": "42", "issue": "S8", "pages": "A80-A80" }, { "id": "authors:vacsz-k6z70", "collection": "authors", "collection_id": "vacsz-k6z70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130724-135008010", "type": "article", "title": "Search for extinct ^(36)Cl in Ca-Al-rich inclusions in primitive ordinary chondrites", "author": [ { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Ushikubo", "given_name": "T.", "clpid": "Ushikubo-Takayuki" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" }, { "family_name": "Kimura", "given_name": "M.", "clpid": "Kimura-Masahiko" } ], "abstract": "The short-lived radionuclide ^(36)Cl decays to either ^(36)Ar\n(98.1%, \u03b2-) or ^(36)S (1.9%, \u03b5 and \u03b2+), with a half life of 3.01 \u00d7 10^5 yr [1]. Recent study has shown that ^(36)S anomalies from the decay of ^(36)Cl exist in sodalite (Na_8Al_6Si_6O_(24)Cl_2) of some Ningqiang CAIs and Allende CAIs and chondrule [2\u20135], but not in sodalite in other CAIs from Allende or Vigarano [6, 7]. In this study, we have expanded the search for ^(36)S anomalies in primitive ordinary chondrites.", "doi": "10.1111/j.1945-5100.2007.tb00601.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2007-08", "series_number": "S8", "volume": "42", "issue": "S8", "pages": "A60" }, { "id": "authors:0mntp-59976", "collection": "authors", "collection_id": "0mntp-59976", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650061000.22", "type": "article", "title": "\u00b3\u2076Cl,\u00b2\u2076Al, and O isotopes in an Allende type B2 CAI: Implications for multiple secondary alteration events in the early solar system", "author": [ { "family_name": "Ushikubo", "given_name": "Takayuki", "orcid": "0000-0002-5934-5076", "clpid": "Ushikubo-Takayuki" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hiyagon", "given_name": "Hajime", "orcid": "0000-0002-2314-5996", "clpid": "Hiyagon-Hajime" }, { "family_name": "Sugiura", "given_name": "Naoji", "clpid": "Sugiura-Naoji" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" } ], "abstract": "We measured \u00b3\u2076Cl-36\u00b3\u2076S and \u00b2\u2076Al-\u00b2\u2076Mg systematics and O isotopes of secondary phases in a moderately altered type B2 CAI (CAI#2) from the Allende CV3 chondrite. CAI#2 has two distinct alteration domains: the anorthite-grossular (An-Grs) domain that mostly consists of anorthite and grossular, and the Na-rich domain that mostly consists of sodalite, anorthite, and Fe-bearing phases. Large \u00b3\u2076S excesses (up to \u223c400\u2030) corresponding to an initial \u00b3\u2076Cl/\u00b3\u2075Cl ratio of (1.4 \u00b1 0.3) \u00d7 10\u207b\u2076 were observed in sodalite of the Na-rich domain, but no resolvable \u00b2\u2076Mg excesses were observed in anorthite and sodalite of the Na-rich domain (the initial \u00b2\u2076Al/\u00b2\u2077Al ratio < 4.4 \u00d7 10\u207b\u2077). If we assume that the \u00b3\u2076Cl-\u00b3\u2076S and the \u00b2\u2076Al-\u00b2\u2076Mg systematics were closed simultaneously, the \u00b3\u2076Cl/\u00b3\u2075Cl ratio would have to be on the order of \u223c10\u207b\u00b2 when CAIs were formed. In contrast to sodalite in Na-rich domain, significant \u00b2\u2076Mg excesses (up to \u223c35\u2030) corresponding to an initial \u00b2\u2076Al/\u00b2\u2077Al ratio of (1.2 \u00b1 0.2) \u00d7 10\u207b\u2075 were identified in anorthite of the An-Grs domain. The \u00b2\u2076Al-\u00b2\u2076Mg systematics of secondary phases in CAI#2 suggest that CAIs experienced multiple alteration events. Some of the alteration processes occurred while \u00b3\u2076Cl (half-life is 0.3 Myr) and \u00b2\u2076Al (half-life is 0.72 Myr) were still alive, whereas others took place much later. Assuming that \u00b2\u2076Al was homogeneously distributed in the solar nebula, our study implies that alteration of CAIs occurred as early as within 1.5 Myr of CAI formation and as late as 5.7 Myr after.", "doi": "10.1111/j.1945-5100.2007.tb00573.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2007-08", "series_number": "7-8", "volume": "42", "issue": "7-8", "pages": "1267-1279" }, { "id": "authors:3s1b7-ap772", "collection": "authors", "collection_id": "3s1b7-ap772", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130723-084406023", "type": "article", "title": "Sub-micron-scale variations in Ti abundance in zircon", "author": [ { "family_name": "Hofmann", "given_name": "A. E.", "clpid": "Hofmann-A-E" }, { "family_name": "Cavosie", "given_name": "A. J.", "clpid": "Cavosie-A-J" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Valley", "given_name": "J. W.", "clpid": "Valley-J-W" }, { "family_name": "Eiler", "given_name": "J. M.", "clpid": "Eiler-J-M" } ], "abstract": "The Ti-in-zircon geothermometer [1,2] can constrain growth and/or re-equilibration temperatures of zircons and is particularly useful for constraining Archean and Hadean events where detrital zircon is the only surviving mineral. Zircons are often small (ca. <100 \u00b5m in the long dimension) and preserve evidence of fine-scale (sub-micron) compositional zonation. Methods for determining Ti adbundances in natural zircons typically analyze domains 10s of microns across, which must average fine-scale compositional variations. Although Ti can correlate with coarse cathodoluminescence (CL) zones (e.g., [3]), it is unknown whether Ti exhibits fine-scale variations and thus may be compromised by coarse-scale measurements.", "doi": "10.1016/j.gca.2007.06.017", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2007-08", "series_number": "15", "volume": "71", "issue": "15", "pages": "A411" }, { "id": "authors:sh9sg-1eb12", "collection": "authors", "collection_id": "sh9sg-1eb12", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650065000.23", "type": "article", "title": "Intercalibration of FTIR and SIMS for hydrogen measurements in glasses and nominally anhydrous minerals", "author": [ { "family_name": "Aubaud", "given_name": "Cyril", "orcid": "0000-0002-0246-6889", "clpid": "Aubaud-Cyril" }, { "family_name": "Withers", "given_name": "Anthony C.", "orcid": "0000-0003-4835-4281", "clpid": "Withers-Anthony-C" }, { "family_name": "Hirschmann", "given_name": "Marc M.", "orcid": "0000-0003-1213-6645", "clpid": "Hirschmann-Marc-M" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "Mackwell", "given_name": "Stephen J.", "orcid": "0000-0002-0996-1348", "clpid": "Mackwell-Stephen-J" }, { "family_name": "Bell", "given_name": "David R.", "clpid": "Bell-David-R" } ], "abstract": "We present new Fourier Transform Infrared Spectroscopy (FTIR) and ion microprobe/secondary ion mass spectrometry (SIMS) analyses of 1H in 61 natural and experimental geological samples. These samples include 8 basaltic glasses (0.17 to 7.65 wt% H2O), 11 rhyolitic glasses (0.143 to 6.20 wt% H2O), 17 olivines (~0 to 910 wt. ppm H2O), 9 orthopyroxenes (~0 to 263 wt. ppm H2O), 8 clinopyroxenes (~0 to 490 wt. ppm H2O), and 8 garnets (~0 to 189 wt. ppm H2O). By careful attention to vacuum quality, the use a Cs+ primary beam, and a resin-free mounting technique, we routinely achieve hydrogen backgrounds equivalent to less than 5 ppm by weight H2O in olivine. Compared to previous efforts, the new calibration extends to a wider range of H2O contents for the minerals and is more reliable owing to a larger number of standards and to characterization of anisotropic minerals by polarized FTIR on oriented crystals. When observed, discrepancies between FTIR and SIMS measurements are attributable to inclusions of hydrous minerals or fluid inclusions in the crystals. Inclusions more commonly interfere with FTIR analyses than with SIMS, owing to the much larger volume sampled by the former. Plots of H2O determined by FTIR vs. (1H/30Si) \u00d7 (SiO2), determined by SIMS and electron microprobe (EMP) yield linear arrays and for each phase appear to be insensitive to bulk composition. For example, basalt and rhyolite calibration slopes cannot be distinguished. On the other hand, calibration slopes of different phases vary by up to a factor of 4. This reflects either phase-specific behavior of 1H/30Si secondary ion ratios excited by Cs+ ion beams or discrepancies between phase-specific FTIR absorption coefficient schemes.", "doi": "10.2138/am.2007.2248", "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": "811-828" }, { "id": "authors:xysdf-tj437", "collection": "authors", "collection_id": "xysdf-tj437", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141118-081613400", "type": "article", "title": "Isotopic Compositions of Cometary Matter Returned by Stardust", "author": [ { "family_name": "McKeegan", "given_name": "Kevin D.", "orcid": "0000-0002-1827-729X", "clpid": "McKeegan-Kevin-D" }, { "family_name": "Al\u00e9on", "given_name": "Jerome", "orcid": "0000-0001-5729-0166" }, { "family_name": "Bradley", "given_name": "John" }, { "family_name": "Brownlee", "given_name": "Donald" }, { "family_name": "Busemann", "given_name": "Henner", "orcid": "0000-0002-0867-6908" }, { "family_name": "Butterworth", "given_name": "Anna", "orcid": "0000-0002-6439-1472" }, { "family_name": "Chaussidon", "given_name": "Marc", "orcid": "0000-0001-8475-0690" }, { "family_name": "Fallon", "given_name": "Stewart", "orcid": "0000-0002-8064-5903" }, { "family_name": "Floss", "given_name": "Christine" }, { "family_name": "Gilmour", "given_name": "Jamie", "orcid": "0000-0003-1990-8636" }, { "family_name": "Gounelle", "given_name": "Matthieu", "orcid": "0000-0002-0455-2262" }, { "family_name": "Graham", "given_name": "Giles" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Heck", "given_name": "Philipp R.", "orcid": "0000-0002-6319-2594" }, { "family_name": "Hoppe", "given_name": "Peter", "orcid": "0000-0003-3681-050X" }, { "family_name": "Hutcheon", "given_name": "Ian D." }, { "family_name": "Huth", "given_name": "Joachim" }, { "family_name": "Ishii", "given_name": "Hope", "orcid": "0000-0002-7976-5078" }, { "family_name": "Ito", "given_name": "Motoo", "orcid": "0000-0001-5686-0243" }, { "family_name": "Jacobsen", "given_name": "Stein B.", "orcid": "0000-0003-2164-0720" }, { "family_name": "Kearsley", "given_name": "Anton" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "Liu", "given_name": "Ming-Chang", "orcid": "0000-0003-4030-5258" }, { "family_name": "Lyon", "given_name": "Ian", "orcid": "0000-0003-4550-2584" }, { "family_name": "Marhas", "given_name": "Kuljeet", "orcid": "0000-0002-3375-3047" }, { "family_name": "Marty", "given_name": "Bernard", "orcid": "0000-0001-7936-1519" }, { "family_name": "Matrajt", "given_name": "Graciela" }, { "family_name": "Meibom", "given_name": "Anders", "orcid": "0000-0002-4542-2819" }, { "family_name": "Messenger", "given_name": "Scott" }, { "family_name": "Mostefaoui", "given_name": "Smail", "orcid": "0000-0002-5941-043X" }, { "family_name": "Mukhopadhyay", "given_name": "Sujoy", "orcid": "0000-0002-8094-898X" }, { "family_name": "Nakamura-Messenger", "given_name": "Keiko", "orcid": "0000-0003-3321-4868" }, { "family_name": "NIttler", "given_name": "Larry", "orcid": "0000-0002-5292-6089" }, { "family_name": "Palma", "given_name": "Russ" }, { "family_name": "Pepin", "given_name": "Robert O." }, { "family_name": "Papanastassiou", "given_name": "Dimitri A." }, { "family_name": "Robert", "given_name": "Fran\u00e7ois" }, { "family_name": "Schlutter", "given_name": "Dennis" }, { "family_name": "Snead", "given_name": "Christopher J." }, { "family_name": "Stadermann", "given_name": "Frank J." }, { "family_name": "Stroud", "given_name": "Rhonda", "orcid": "0000-0001-5242-8015" }, { "family_name": "Tsou", "given_name": "Peter" }, { "family_name": "Westphal", "given_name": "Andrew", "orcid": "0000-0003-1156-3776" }, { "family_name": "Young", "given_name": "Edward D.", "orcid": "0000-0002-1299-0801" }, { "family_name": "Ziegler", "given_name": "Karen" }, { "family_name": "Zimmerman", "given_name": "Laurent" }, { "family_name": "Zinner", "given_name": "Ernst" } ], "abstract": "Hydrogen, carbon, nitrogen, and oxygen isotopic compositions are heterogeneous among comet 81P/Wild 2 particle fragments; however, extreme isotopic anomalies are rare, indicating that the comet is not a pristine aggregate of presolar materials. Nonterrestrial nitrogen and neon isotope ratios suggest that indigenous organic matter and highly volatile materials were successfully collected. Except for a single ^(17)O-enriched circumstellar stardust grain, silicate and oxide minerals have oxygen isotopic compositions consistent with solar system origin. One refractory grain is ^(16)O-enriched, like refractory inclusions in meteorites, suggesting that Wild 2 contains material formed at high temperature in the inner solar system and transported to the Kuiper belt before comet accretion.", "doi": "10.1126/science.1135992", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2006-12-15", "series_number": "5806", "volume": "314", "issue": "5806", "pages": "1724-1728" }, { "id": "authors:mk0kp-twn35", "collection": "authors", "collection_id": "mk0kp-twn35", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141112-085628838", "type": "article", "title": "Comet 81P/Wild 2 Under a Microscope", "author": [ { "family_name": "Brownlee", "given_name": "Don", "clpid": "Brownlee-Donald" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Papanastassiou", "given_name": "Dimitri A.", "clpid": "Papanastassiou-D-A" } ], "abstract": "The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.", "doi": "10.1126/science.1135840", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2006-12-15", "series_number": "5806", "volume": "314", "issue": "5806", "pages": "1711-1716" }, { "id": "authors:gtsv5-hy306", "collection": "authors", "collection_id": "gtsv5-hy306", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130131-131759052", "type": "article", "title": "The solar wind FE/MG ratio", "author": [ { "family_name": "Burnett", "given_name": "D. S.", "orcid": "0000-0001-9521-8675", "clpid": "Burnett-D-S" }, { "family_name": "Jurewicz", "given_name": "A. J. G.", "orcid": "0000-0002-3282-5782", "clpid": "Jurewicz-A-J-G" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Woolum", "given_name": "D. S.", "clpid": "Woolum-D-S" }, { "family_name": "McKeegan", "given_name": "K.", "clpid": "McKeegan-K-D" } ], "abstract": "To meet the Genesis mission goal for improved solar elemental abundances, we need to address the issue of fractionation of the abundances of elements in the solar wind compared to the solar photosphere. There is a well-established depletion of elements in the solar wind with high first ionization potential (FIP > 9eV) compared to lower FIP elements, but there is no evidence for fractionation between lower FIP elements.", "doi": "10.1111/j.1945-5100.2006.tb00996.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2006-08", "series_number": "S8", "volume": "41", "issue": "S8", "pages": "A33" }, { "id": "authors:d8s53-9b159", "collection": "authors", "collection_id": "d8s53-9b159", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650224000.30", "type": "article", "title": "Oxide-bearing and FeO-rich clasts in aubrites", "author": [ { "family_name": "Rosenshein", "given_name": "E. B.", "clpid": "Rosenshein-E-B" }, { "family_name": "Ivanova", "given_name": "M. A.", "orcid": "0000-0002-8365-6958", "clpid": "Ivanova-Marina-A" }, { "family_name": "Dickinson", "given_name": "T. L.", "clpid": "Dickinson-Tamara-L" }, { "family_name": "McCoy", "given_name": "T. J.", "orcid": "0000-0002-4573-3553", "clpid": "McCoy-Timothy-J" }, { "family_name": "Lauretta", "given_name": "D. S.", "orcid": "0000-0002-2597-5950", "clpid": "Lauretta-Dante-S" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" }, { "family_name": "Benedix", "given_name": "G. K.", "orcid": "0000-0003-0990-8878", "clpid": "Benedix-Gretchen-K" } ], "abstract": "We report the occurrence of an oxide-bearing clast and an FeO-rich clast from aubrites. The FeO-rich clast in Pesyanoe is dominated by olivine and pyroxene phenocrysts with mineral compositions slightly less FeO-rich than is typical for H chondrites. In Allan Hills (ALH) 84008, the oxide-bearing clast consists of a single forsterite grain rimmed by an array of sulfides, oxides, and phosphides. We consider a number of possible origins. We can exclude formation by melting of oxide-bearing chondrules and CAIs formed in enstatite chondrites. The Pesyanoe clast may have formed in a more oxidized region of the aubrite parent body or, more likely, is a foreign clast from a more oxidized parent body. The ALH 84008 clast likely formed by reaction between sulfides and silicates as a result of cooling, oxidation, or de-sulfidization. This clast appears to be the first oxide-bearing clast from an aubritic breccia that formed on the aubrite parent body. Identification of additional oxide-bearing clasts in aubrites could shed light on whether this was a widespread phenomenon and the origin of these enigmatic objects.", "doi": "10.1111/j.1945-5100.2006.tb00477.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2006-04", "series_number": "4", "volume": "41", "issue": "4", "pages": "495-503" }, { "id": "authors:1956c-gm245", "collection": "authors", "collection_id": "1956c-gm245", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650247000.32", "type": "article", "title": "Useful ion yields for Cameca IMS 3f and 6f SIMS: Limits on quantitative analysis", "author": [ { "family_name": "Hervig", "given_name": "Richard L.", "orcid": "0000-0001-7892-5423", "clpid": "Hervig-Richard-L" }, { "family_name": "Mazdab", "given_name": "Frank K.", "orcid": "0000-0002-1577-8857", "clpid": "Mazdab-Frank-K" }, { "family_name": "Williams", "given_name": "Peter", "clpid": "Williams-Peter" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Huss", "given_name": "Gary R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-Gary-R" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" } ], "abstract": "The useful yields (ions detected/atom sputtered) of major and trace elements in NIST 610 glass were measured by secondary ion mass spectrometry (SIMS) using Cameca IMS 3f and 6f instruments. Useful yields of positive ions at maximum transmission range from 10\u207b\u2074 to 0.2 and are negatively correlated with ionization potential. We quantified the decrease in useful yields when applying energy filtering or high mass resolution techniques to remove molecular interferences. The useful yields of selected negative ions (O, S, Au) in magnetite and pyrite were also determined. These data allow the analyst to determine if a particular analysis (trace element contents or isotopic ratio) can be achieved, given the amount of sample available and the conditions of the analysis.", "doi": "10.1016/j.chemgeo.2005.09.008", "issn": "0009-2541", "publisher": "Elsevier", "publication": "Chemical Geology", "publication_date": "2006-03-20", "series_number": "1-2", "volume": "227", "issue": "1-2", "pages": "83-99" }, { "id": "authors:7jzj2-vmc44", "collection": "authors", "collection_id": "7jzj2-vmc44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131211-141250305", "type": "article", "title": "A Late Episode of Irradiation in the Early Solar System: Evidence from Extinct ^(36)Cl and ^(26)Al in Meteorites", "author": [ { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" }, { "family_name": "Ushikubo", "given_name": "Takayuki", "clpid": "Ushikubo-Takayuki" }, { "family_name": "Wasserburg", "given_name": "G. J.", "orcid": "0000-0002-7957-8029", "clpid": "Wasserburg-G-J" } ], "abstract": "Late-formed halogen-rich phases in a refractory inclusion and a chondrule from the Allende meteorite exhibit large ^(36)S excesses that linearly correlate with the chlorine concentration, providing strong evidence in support of the existence of the short-lived nuclide ^(36)Cl (mean life of 0.43 Myr) in the early solar system. The inferred ^(36)Cl/^(35)Cl ratios at the time when these phases formed are very high (~4 \u00d7 10^(-6)) and essentially the same for the inclusion and the chondrule and confirm the earlier report of ^(36)S excess in another meteorite. In addition, the ^(36)Cl is decoupled from ^(26)Al. The observed and any possible higher levels of ^(36)Cl cannot be the result of a supernova or AGB stellar source but require a late episode of energetic particle bombardment by the early Sun, in support of the arguments based on the previous discovery of ^(10)Be. It is now clear that a blend of several sources is required to explain the short-lived nuclei when the solar system formed.", "doi": "10.1086/500043", "issn": "0004-637X", "publisher": "American Astronomical Society", "publication": "Astrophysical Journal", "publication_date": "2006-03-20", "series_number": "1", "volume": "640", "issue": "1", "pages": "525-529" }, { "id": "authors:f0x2z-qhs76", "collection": "authors", "collection_id": "f0x2z-qhs76", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650252000.34", "type": "article", "title": "Aqueous alteration of opaque assemblages in the Ningqiang carbonaceous chondrite: Evidence from oxygen isotopes", "author": [ { "family_name": "Hsu", "given_name": "Weibiao", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Hua", "given_name": "Xin", "clpid": "Hua-Xin" }, { "family_name": "Wang", "given_name": "Ying", "clpid": "Wang-Ying" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" }, { "family_name": "Sharp", "given_name": "T. G.", "orcid": "0000-0003-2287-9370", "clpid": "Sharp-Thomas-G" } ], "abstract": "Chondrules and matrix of the Ningqiang carbonaceous chondrite contain numerous opaque assemblages (OAs). These OAs are mainly composed of Ni-rich metal, magnetite, sulfides, phosphates with minor amounts of silicates and trace amounts of Pt-metal grains. Their mineral assemblage is very similar to that of OAs found in Allende refractory inclusions. In this study, we performed in situ analyses of O-isotopic compositions of magnetite and whitlockite in OAs and of olivine adjacent to OAs from Ningqiang. O-isotopic compositions of magnetite vary by 16\u2030 in \u03b4\u00b9\u2078O and fall on a regression line with a slope of 0.51 and a mean \u0394\u00b9\u2077O of \u2212 2.9 \u00b1 0.3 (1\u03c3)\u2030 in the three-O-isotope diagram. Magnetite grains have consistently higher \u0394\u00b9\u2077O values than their adjacent olivine grains. The mineral chemistry and O-isotopic compositions of OAs in Ningqiang chondrules and matrix are most consistent with the formation of magnetites and whitlockite by aqueous alteration of preexisting metal alloys within a planetary body. Formation of magnetites and phosphates in OAs thus do not constrain processes in the early solar nebula, but rather provide information on metamorphism in a planetary environment.", "doi": "10.1016/j.epsl.2005.12.021", "issn": "0012-821X", "publisher": "Elsevier", "publication": "Earth and Planetary Science Letters", "publication_date": "2006-03-15", "series_number": "1-2", "volume": "243", "issue": "1-2", "pages": "107-114" }, { "id": "authors:4cmnk-zhd04", "collection": "authors", "collection_id": "4cmnk-zhd04", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650267000.36", "type": "article", "title": "Oxygen isotope and \u00b2\u2076Al-\u00b2\u2076Mg systematics of aluminum-rich chondrules from unequilibrated enstatite chondrites", "author": [ { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Huss", "given_name": "Gary R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-Gary-R" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "MacPherson", "given_name": "Glenn J.", "clpid": "MacPherson-Glenn-J" }, { "family_name": "McKeegan", "given_name": "Kevin D.", "orcid": "0000-0002-1827-729X", "clpid": "McKeegan-Kevin-D" } ], "abstract": "Correlated in situ analyses of the oxygen and magnesium isotopic compositions of aluminum-rich chondrules from unequilibrated enstatite chondrites were obtained using an ion microprobe. Among eleven aluminum-rich chondrules and two plagioclase fragments measured for \u00b2\u2076Al-\u00b2\u2076Mg systematics, only one aluminum-rich chondrule contains excess \u00b2\u2076Mg from the in situ decay of \u00b2\u2076Al; the inferred initial ratio (\u00b2\u2076Al/\u00b2\u2077Al)\u2092 = (6.8 \u00b1 2.4) \u00d7 10\u207b\u2076 is consistent with ratios observed in chondrules from carbonaceous chondrites and unequilibrated ordinary chondrites. \n\nThe oxygen isotopic compositions of five aluminum-rich chondrules and one plagioclase fragment define a line of slope \u02dc0.6 \u00b1 0.1 on a three-oxygen-isotope diagram, overlapping the field defined by ferromagnesian chondrules in enstatite chondrites but extending to more \u00b9\u2076O-rich compositions with a range in \u03b4\u00b9\u2078O of about \u02dc12\u2030. Based on their oxygen isotopic compositions, aluminum-rich chondrules in unequilibrated enstatite chondrites are probably genetically related to ferromagnesian chondrules and are not simple mixtures of materials from ferromagnesian chondrules and calcium-aluminum-rich inclusions (CAIs). \n\nRelative to their counterparts from unequilibrated ordinary chondrites, aluminum-rich chondrules from unequilibrated enstatite chondrites show a narrower oxygen isotopic range and much less resolvable excess \u00b2\u2076Mg from the in situ decay of \u00b2\u2076Al, probably resulting from higher degrees of equilibration and isotopic exchange during post-crystallization metamorphism. However, the presence of \u00b2\u2076Al-bearing chondrules within the primitive ordinary, carbonaceous, and now enstatite chondrites suggests that \u00b2\u2076Al was at least approximately homogeneously distributed across the chondrite-forming region.", "doi": "10.1111/j.1945-5100.2006.tb00191.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2006-01", "series_number": "1", "volume": "41", "issue": "1", "pages": "33-47" }, { "id": "authors:54cjz-e4m32", "collection": "authors", "collection_id": "54cjz-e4m32", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650287000.39", "type": "article", "title": "Petrogenesis of the new lherzolitic shergottite Grove Mountains 99027: Constraints of petrography, mineral chemistry, and rare earth elements", "author": [ { "family_name": "Lin", "given_name": "Yangting", "orcid": "0000-0002-3407-4329", "clpid": "Lin-Yangting" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Daode", "clpid": "Wang-Daode" }, { "family_name": "Kimura", "given_name": "Makoto", "orcid": "0000-0003-3352-4989", "clpid": "Kimura-Makoto" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" } ], "abstract": "We report petrography, mineral chemistry, and microdistribution of rare earth elements (REE) in a new lherzolitic shergottite, Grove Mountains (GRV) 99027. The textural relationship and REE patterns of minerals suggest precipitation of cumulus olivine and chromite, followed by equilibrium crystallization of a closed system with a bulk composition of the inferred intercumulus melt. Subsolidus equilibrium temperatures of pyroxenes and olivine range from 1100 to 1210 \u00b0C, based on a two-pyroxene thermometry and Ca partitioning between augite and olivine. Oxygen fugacity of the parent magma is 1.5\u20132.5 (av. 2.0 \u00b1 0.4) log units below the quartz-fayalite-magnetite (QFM) buffer at 960\u20131360 \u00b0C, according to the olivine-orthopyroxene-chromite barometer. The ilmenite-chromite barometer and thermometer show much wider ranges of oxygen fugacity (1.0\u20137.0 log unit below QFM) and temperature (1130\u2013480 \u00b0C), suggesting subsolidus equilibration of the oxides at low temperatures, probably due to deep burial of GRV 99027 on Mars. The low oxygen fugacity and LREE depletion of the parent magma of GRV 99027 suggest low contamination by martian crust. \n\nCharacteristics of GRV 99027 demonstrate similarity of lherzolitic shergottites, suggesting a high possibility of launch pairing or a homogeneous upper mantle of Mars if they were ejected by individual impact events. However, GRV 99027 probably experienced severe post-shock thermal metamorphism in comparison with other lherzolitic shergottites, based on the re-crystallization of maskelynite, the homogeneity of minerals, and the low subsolidus equilibrium temperatures between chromite and ilmenite.", "doi": "10.1111/j.1945-5100.2005.tb00134.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2005-11", "series_number": "11", "volume": "40", "issue": "11", "pages": "1599-1619" }, { "id": "authors:axr9a-1z082", "collection": "authors", "collection_id": "axr9a-1z082", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650310000.43", "type": "article", "title": "Microscale carbon isotope variability in ALH84001 carbonates and a discussion of possible formation environments", "author": [ { "family_name": "Niles", "given_name": "P. B.", "orcid": "0000-0001-7612-1421", "clpid": "Niles-Paul-B" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" }, { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" } ], "abstract": "The carbonates in martian meteorite ALH84001 preserve a record of aqueous processes on Mars at 3.9 Ga, and have been suggested to contain signatures of ancient martian life. The conditions of the carbonate formation environment are critical for understanding possible evidence for life on Mars, the history of water on Mars, and the evolution of the martian atmosphere. Despite numerous studies of petrographic relationships, microscale oxygen isotope compositions, microscale chemical compositions, and other minerals associated with the carbonates, formation models remain relatively unconstrained. Microscale carbon isotope analyses of ALH84001 carbonates reveal variable \u03b4\u00b9\u00b3C values ranging from +27 to +64\u2030. The isotopic compositions are correlated with chemical composition and extent of crystallization such that the Mg-poor, early-formed carbonates are relatively \u00b9\u00b3C depleted and the Mg-rich, later forming carbonates, are \u00b9\u00b3C enriched. These data are inconsistent with many of the previously proposed environments for carbonate formation, and a new set of hypotheses are proposed. Specifically, two new models that account for the data involve low temperature (<100\u00b0C) aqueous processes: (1) the carbonates formed during mixing of two fluids derived from separate chemical and isotopic reservoirs; or (2) the carbonates formed from high pH fluids that are exposed to a CO\u2082-rich atmosphere and precipitate carbonate, similar to high pH springs on Earth.", "doi": "10.1016/j.gca.2004.12.012", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2005-06-01", "series_number": "11", "volume": "69", "issue": "11", "pages": "2931-2944" }, { "id": "authors:dn7cr-z8667", "collection": "authors", "collection_id": "dn7cr-z8667", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650392000.45", "type": "article", "title": "Short-lived chlorine-36 in a Ca- and Al-rich inclusion from the Ningqiang carbonaceous chondrite", "author": [ { "family_name": "Lin", "given_name": "Yangting", "orcid": "0000-0002-3407-4329", "clpid": "Lin-Yangting" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "Ouyang", "given_name": "Ziyuan", "clpid": "Ouyang-Ziyuan" }, { "family_name": "Wang", "given_name": "Daode", "clpid": "Wang-Daode" } ], "abstract": "Excesses of sulfur-36 in sodalite, a chlorine-rich mineral, in a calcium- and aluminum-rich inclusion from the Ningqiang carbonaceous chondrite linearly correlate with chorine/sulfur ratios, providing direct evidence for the presence of short-lived chlorine-36 (with a half-life of 0.3 million years) in the early solar system. The best inferred (\u00b3\u2076Cl/\u00b3\u2075Cl)\u2092 ratios of the sodalite are \u22485 \u00d7 10\u207b\u2076. Different from other short-lived radionuclides, chlorine-36 was introduced into the inclusion by solid-gas reaction during secondary alteration. The alteration reaction probably took place at least 1.5 million years after the first formation of the inclusion, based on the correlated study of the \u00b2\u2076Al-\n\u00b2\u2076Mg systems of the relict primary minerals and the alteration assemblages, from which we inferred an initial ratio of (\u00b3\u2076Cl/\u00b3\u2075Cl)\u2092 > 1.6 \u00d7 10\u207b\u2074 at the time when calcium- and aluminum-rich inclusions formed. This discovery supports a supernova origin of short-lived nuclides [Cameron, A. G. W., Hoeflich, P., Myers, P. C. & Clayton, D. D. (1995) Astrophys. J. 447, L53; Wasserburg, G. J., Gallino, R. & Busso, M. (1998) Astrophys. J. 500, L189\u2013L193], but presents a serious challenge for local irradiation models [Shu, F. H., Shang, H., Glassgold, A. E. & Lee, T. (1997) Science 277, 1475\u20131479; Gounelle, M., Shu, F. H., Shang, H., Glassgold, A. E., Rehm, K. E. & Lee, T. (2001) Astrophys. J. 548, 1051\u20131070]. Furthermore, the short-lived \u00b3\u2076Cl may serve as a unique fine-scale chronometer for volatile-rock interaction in the early solar system because of its close association with aqueous and/or anhydrous alteration processes.", "doi": "10.1073/pnas.0407173101", "pmcid": "PMC547833", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "2005-02-01", "series_number": "5", "volume": "102", "issue": "5", "pages": "1306-1311" }, { "id": "authors:1kama-ptz97", "collection": "authors", "collection_id": "1kama-ptz97", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650407000.47", "type": "article", "title": "Oxygen isotope heterogeneity in chondrules from the Mokoia CV3 carbonaceous chondrite", "author": [ { "family_name": "Jones", "given_name": "Rhian H.", "orcid": "0000-0001-8238-9379", "clpid": "Jones-Rhian-H" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Sharp", "given_name": "Zachary D.", "orcid": "0000-0003-1902-5542", "clpid": "Sharp-Zachary-D" }, { "family_name": "Durakiewicz", "given_name": "Tomasz", "orcid": "0000-0002-1980-1874", "clpid": "Durakiewicz-Tomasz" }, { "family_name": "Schilk", "given_name": "Alan J.", "clpid": "Schilk-Alan-J" } ], "abstract": "We report a study of the oxygen isotope ratios of chondrules and their constituent mineral grains from the Mokoia, oxidized CV3 chondrite. Bulk oxygen isotope ratios of 23 individual chondrules were determined by laser ablation fluorination, and oxygen isotope ratios of individual grains, mostly olivine, were obtained in situ on polished mounts using secondary ion mass spectrometry (SIMS). Our results can be compared with data obtained previously for the oxidized CV3 chondrite, Allende. Bulk oxygen isotope ratios of Mokoia chondrules form an array on an oxygen three-isotope plot that is subparallel to, and slightly displaced from, the CCAM (carbonaceous chondrite anhydrous minerals) line. The best-fit line for all CV3 chondrite chondrules has a slope of 0.99, and is displaced significantly (by \u03b4\u00b9\u2077O \u223c \u22122.5\u2030) from the Young and Russell slope-one line for unaltered calcium-aluminum-rich inclusion (CAI) minerals. Oxygen isotope ratios of many bulk CAIs also lie on the CV-chondrule line, which is the most relevant oxygen isotope array for most CV chondrite components. Bulk oxygen isotope ratios of most chondrules in Mokoia have \u03b4\u00b9\u2078O values around 0\u2030, and olivine grains in these chondrules have similar oxygen isotope ratios to their bulk values. In general, it appears that chondrule mesostases have higher \u03b4\u00b9\u2078O values than olivines in the same chondrules. Our bulk chondrule data spread to lower \u03b4\u00b9\u2078O values than any ferromagnesian chondrules that have been measured previously. Two chondrules with the lowest bulk \u03b4\u00b9\u2078O values (\u22127.5\u2030 and \u221211.7\u2030) contain olivine grains that display an extremely wide range of oxygen isotope ratios, down to \u03b4\u00b9\u2077O, \u03b418O around -50\u2030 in one chondrule. In these chondrules, there are no apparent relict grains, and essentially no relationships between olivine compositions, which are homogeneous, and oxygen isotopic compositions of individual grains. Heterogeneity of oxygen isotope ratios within these chondrules may be the result of incorporation of relict grains from objects such as amoeboid olivine aggregates, followed by solid-state chemical diffusion without concomitant oxygen equilibration. Alternatively, oxygen isotope exchange between an \u00b9\u2076O-rich precursor and an \u00b9\u2076O-poor gas may have taken place during chondrule formation, and these chondrules may represent partially equilibrated systems in which isotopic heterogeneities became frozen into the crystallizing olivine grains. If this is the case, we can infer that the earliest nebular solids from which chondrules formed had \u03b4\u00b9\u2077O and \u03b4\u00b9\u2078O values around -50\u2030, similar to those observed in refractory inclusions.", "doi": "10.1016/j.gca.2004.01.013", "issn": "0016-7037", "publisher": "Elsevier", "publication": "Geochimica et Cosmochimica Acta", "publication_date": "2004-08-15", "series_number": "16", "volume": "68", "issue": "16", "pages": "3423-3438" }, { "id": "authors:nrzxh-4vt44", "collection": "authors", "collection_id": "nrzxh-4vt44", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650417000.49", "type": "article", "title": "SIMS analyses of Mg, Cr, and Ni isotopes in primitive meteorites and short-lived radionuclides in the early solar system", "author": [ { "family_name": "Guan", "given_name": "Y.", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Huss", "given_name": "G. R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-Gary-R" }, { "family_name": "Leshin", "given_name": "L. A.", "clpid": "Leshin-L-A" } ], "abstract": "SIMS analyses of \u00b2\u2076Al\u2013\u00b2\u2076Mg, \u2076\u2070Fe\u2013\u2076\u2070Ni, and \u2075\u00b3Mn\u2013\u2075\u00b3Cr systems in unequilibrated enstatite chondrites provide evidence for the former existence of \u00b2\u2076Al, \u2076\u2070Fe, and \u2075\u00b3Mn in this highly reduced meteorite group, suggesting the widespread of these short-lived radionuclides in the early solar system. Calcium\u2013aluminum-rich inclusions and Al-rich chondrules in enstatite chondrites show \u00b2\u2076Al\u2013\u00b2\u2076Mg characteristics similar to their counterparts in other types of chondrites. Assuming its homogenous distribution, fine-scale \u00b2\u2076Al relative chronology can be obtained for different components in meteorites. Well-defined isochrons yield initial \u2076\u2070Fe/\u2075\u2076Fe ratios of (0.3\u22121) \u00d7 10\u207b\u2076 in sulfides from enstatite chondrites. The former presence of \u2076\u2070Fe suggests a stellar source and its possible high abundance points to a supernova origin. \u00b2\u2076Al and \u2076\u2070Fe could be important heat sources for the early planetary processes. The large variations of initial \u2076\u2070Fe/\u2075\u2076Fe and \u2075\u00b3Mn/\u2075\u2075Mn ratios and the discordance between \u2076\u2070Fe\u2013\u2076\u2070Ni and \u2075\u00b3Mn\u2013\u2075\u00b3Cr systems observed in sulfides indicate later disturbance of the two isotopic systems, and therefore, bear no strict chronological significance. SIMS isotopic analysis can be utilized to attain important information about the early evolution of the solar system.", "doi": "10.1016/j.apsusc.2004.03.163", "issn": "0169-4332", "publisher": "Elsevier", "publication": "Applied Surface Science", "publication_date": "2004-06-15", "volume": "231-232", "pages": "899-902" }, { "id": "authors:w8hne-4wv09", "collection": "authors", "collection_id": "w8hne-4wv09", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20230307-650431000.52", "type": "article", "title": "The lherzolitic shergottite Grove Mountains 99027: Rare earth element geochemistry", "author": [ { "family_name": "Hsu", "given_name": "Weibiao", "orcid": "0000-0003-2550-8137", "clpid": "Hsu-Weibiao" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Wang", "given_name": "Henian", "clpid": "Wang-Henian" }, { "family_name": "Leshin", "given_name": "Laurie A.", "clpid": "Leshin-L-A" }, { "family_name": "Wang", "given_name": "Rucheng", "orcid": "0000-0002-2076-5073", "clpid": "Wang-Rucheng" }, { "family_name": "Zhang", "given_name": "Wenlan", "clpid": "Zhang-Wenlan" }, { "family_name": "Chen", "given_name": "Xiaoming", "clpid": "Chen-Xiaoming" }, { "family_name": "Zhang", "given_name": "Fusheng", "clpid": "Zhang-Fusheng" }, { "family_name": "Lin", "given_name": "Chengyi", "clpid": "Lin-Chengyi" } ], "abstract": "We report here on an ion probe study of rare earth element (REE) geochemistry in the lherzolitic shergottite Grove Mountains (GRV) 99027. This meteorite shows almost identical mineralogy, petrology, and REE geochemistry to those of the lherzolitic shergottites Allan Hills (ALH) A77005, Lewis Cliff (LEW) 88516, and Yamato (Y-) 793605. REE concentrations in olivine, pyroxenes, maskelynite, merrillite, and melt glass are basically comparable to previous data obtained from ALH A77005, LEW 88516, and Y-793605. Olivine is the dominant phase in this meteorite. It is commonly enclosed by large (up to several mm) pigeonite oikocrysts. Non-poikilitic areas consist of larger olivine grains (\u02dcmm), pigeonite, augite, and maskelynite. Minor merrillite (up to 150 \u03bcm in size) is widespread in non-poikilitic regions, occurring interstitially between olivine and pyroxene grains. It is the main REE carrier in GRV 99027 and has relatively higher REEs (200\u20131000 \u00d7 CI) than that of other lherzolitic shergottites. A REE budget calculation for GRV 99027 yields a whole rock REE pattern very similar to that of other lherzolites. It is characterized by the distinctive light REE depletion and a smooth increase from light REEs to heavy REEs. REE microdistributions in GRV 99027 strongly support the idea that all lherzolitic shergottites formed by identical igneous processes, probably from the same magma chamber on Mars. \n\nDespite many similarities in mineralogy, petrography, and trace element geochemistry, subtle differences exist between GRV 99027 and other lherzolitic shergottites. GRV 99027 has relatively uniform mineral compositions (both major elements and REEs), implying that it suffered a higher degree of sub-solidus equilibration than the other three lherzolites. It is notable that GRV 99027 has experienced terrestrial weathering in the Antarctic environment, as its olivine and pyroxenes commonly display a light REE enrichment and a negative Ce anomaly. Caution needs to be taken in future chronological studies.", "doi": "10.1111/j.1945-5100.2004.tb00113.x", "issn": "1086-9379", "publisher": "Meteoritical Society", "publication": "Meteoritics and Planetary Science", "publication_date": "2004-05", "series_number": "5", "volume": "39", "issue": "5", "pages": "701-709" }, { "id": "authors:zt1q9-8q262", "collection": "authors", "collection_id": "zt1q9-8q262", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20130415-102910989", "type": "article", "title": "Analysis of hydrogen in olivine by SIMS: Evaluation of standards and protocol", "author": [ { "family_name": "Mosenfelder", "given_name": "Jed L.", "clpid": "Mosenfelder-J-L" }, { "family_name": "Le Voyer", "given_name": "Marion", "clpid": "Le-Voyer-M" }, { "family_name": "Rossman", "given_name": "George R.", "orcid": "0000-0002-4571-6884", "clpid": "Rossman-G-R" }, { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Bell", "given_name": "David R.", "clpid": "Bell-D-R" }, { "family_name": "Eiler", "given_name": "John M.", "clpid": "Eiler-J-M" }, { "family_name": "Asimow", "given_name": "Paul D.", "orcid": "0000-0001-6025-8925", "clpid": "Asimow-P-D" } ], "abstract": "We measured hydrogen concentrations in 12 olivines using secondary ion mass spectrometry (SIMS and NanoSIMS), cross-calibrated against Fourier transform infrared (FTIR) spectroscopy and nuclear reaction analysis (NRA). Five of these samples are routinely used for calibration in other laboratories. We assess the suitability of these olivines as standards based on over 300 SIMS analyses, comprising 22 separate calibrations. Seven olivines with 0\u2013125 ppm H_(2)O give highly reproducible results; in contrast to previous studies, the data are fit to well-constrained calibration lines with high correlation coefficients (r^2 = 0.98\u20131). However, four kimberlitic megacrysts with 140\u2013245 ppm H2O sometimes yield ^(16)O^(1)H/^(30)Si ratios that have low internal precision and can vary by up to a factor of two even in sequential analyses. A possible cause of this behavior is the presence of sub-microscopic inclusions of hydrous minerals, such as serpentine. In most cases, however, we link the anomalous results to the presence of sub-micrometer to micrometer-scale pores (as small as 100 nm), which we imaged using SEM and NanoSIMS. These pores are interpreted to be fluid inclusions containing liquid H_(2)O, other volatiles (including fluorine), and/or hydrous phase precipitates. Ionization of the contents of the pores contributes variably to the measured ^(16)O^(1)H, resulting in analyses with erratic depth profiles and corresponding high uncertainties (up to 16%, 2\u03c3_mean). After filtering of these analyses using a simple criterion based on the error predicted by Poisson counting statistics, all the data fit well together. Our results imply that the Bell et al. (2003) calibration can be applied accurately to all olivines with IR bands from ~3400\u20133700 cm^(\u22121), without the need for band-specific IR absorption coefficients.", "doi": "10.2138/am.2011.3810", "issn": "0003-004X", "publisher": "Mineralogical Society of America", "publication": "American Mineralogist", "publication_date": "2001-11", "series_number": "11-12", "volume": "96", "issue": "11-12", "pages": "1725-1741" }, { "id": "authors:erf20-r3d37", "collection": "authors", "collection_id": "erf20-r3d37", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20131219-100635152", "type": "article", "title": "Calcium-Aluminum-Rich Inclusions from Enstatite Chondrites: Indigenous or Foreign?", "author": [ { "family_name": "Guan", "given_name": "Yunbin", "orcid": "0000-0002-7636-3735", "clpid": "Guan-Yunbin" }, { "family_name": "Huss", "given_name": "Gary R.", "orcid": "0000-0003-4281-7839", "clpid": "Huss-G-R" }, { "family_name": "MacPherson", "given_name": "Glenn J.", "clpid": "MacPherson-G-J" }, { "family_name": "Wasserburg", "given_name": "Gerald J.", "orcid": "0000-0002-7957-8029", "clpid": "Wasserburg-G-J" } ], "abstract": "The primary mineral assemblages and initial ^(26)Al/^(27)Al ratios of rare calcium-aluminum\u2013rich inclusions (CAIs) from enstatite (E) chondrites are similar to those of CAIs from other chondrite classes. CAIs from all chondrite classes formed under oxidizing conditions that are much different from the reducing conditions under which the E chondrites formed. Either CAIs formed at an earlier, more oxidizing epoch in the region where E chondrites ultimately formed, or they formed at a different place in the solar nebula and were transported into the E chondrite formation region.", "doi": "10.1126/science.289.5483.1330", "issn": "0036-8075", "publisher": "American Association for the Advancement of Science", "publication": "Science", "publication_date": "2000-08-25", "series_number": "5483", "volume": "289", "issue": "5483", "pages": "1330-1333" } ]