^1,2Yoko Kebukawa et al.(>10)
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14064]
¹Department of Chemistry and Life Science, Yokohama National University, Yokohama, Japan
²Yoko Kebukawa, Department of Chemistry and Life Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan.
Published by arrangement withe John Wiley & Sons

The infrared spectral characteristics of organic-rich acid residues prepared from Ryugu samples returned by the JAXA Hayabusa2 mission generally match those from unheated carbonaceous chondrite meteorites, but the residues from Ryugu are richer in methyl and methylene functional groups and have higher CH2/CH3 ratios. Moreover, two distinct outlier carbonaceous phases are found; one with spectral characteristics of N-H functional groups, likely amides, and a second phase containing less nitrogen. Such infrared characteristics of Ryugu organic matter might indicate the pristine nature of the freshly collected samples and reflect the near-surface chemistry in the parent asteroid.

¹Liam D. Peterson,¹Megan E. Newcombe,²Conel M.O’D. Alexander,²Jianhua Wang,⁴Frieder Klein,^3,5,6David V. Bekaert,^3,5Sune G. Nielsen
Earth and Planetary Science Letters 620, 118341 Link to Article [https://doi.org/10.1016/j.epsl.2023.118341]
¹Department of Geology, University of Maryland, College Park, MD 20740, United States
²Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, United States
³NIRVANA Labs, Woods Hole Oceanographic Institution, Woods Hole, MA 02540, United States
⁴Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02540, United States
⁵Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02540, United States
⁶Université de Lorraine, CNRS, CRPG, 54000 Nancy, France
Copyright Elsevier

Aubrites and enstatite chondrites (ECs) are isotopically similar to the Earth and therefore may resemble the primary materials that accreted to form our planet. Recent bulk H elemental and isotopic analyses of ECs and the Norton County aubrite suggest that enstatite-rich materials are H-rich and may represent a significant source of terrestrial water, with measured values of 3000±2000 μg/g H2O and 5300±900 μg/g H2O in the bulk and enstatite fractions of Norton County (Piani et al., Science, 2020). Here, we present a detailed investigation of in situ H2O concentrations in enstatite, diopside, forsterite, and plagioclase from a suite of main group aubrites, including Norton County, and Shallowater. We find that enstatite (4±2 μg/g H2O), diopside (4.8±0.5 μg/g H2O), and forsterite (5±3 μg/g H2O) have similar H2O concentrations, and all are significantly lower than plagioclase (24±3 μg/g H2O). We combine our in situ analyses of H2O contents with equilibrium partition coefficients and bulk mineralogies to estimate the bulk H2O content of our samples. We compare these first order estimates with bulk volatile analyses conducted using sample pyrolysis and find that the previous bulk H2O analyses of aubrites predominantly reflect terrestrial contamination and alteration. If our conclusion that the reported bulk H2O analyses of Norton County primarily reflect terrestrial contamination and alteration extends to bulk analyses of ECs, then EC-like material may not be a significant source of terrestrial water. Our results support the hypothesis that thermal metamorphism, melting, and differentiation leads to efficient desiccation of planetesimals relative to chondrites, and that differentiated planetesimals contributed, at most, trace amounts to Earth’s water budget.

¹Chandran, Saranya R.,¹James S.,¹Aswathi J.,¹Padmakumar, Devika,¹Marjan, T. Sadeeda,¹Kumar, R.B. Binoj,^2,4Chavan, Anil,²Bhandari, Subhash ^1,3Sajinkumar K.S.
Earth-Science Reviews 243, 104508 Link to Article [DOI 10.1016/j.earscirev.2023.104508]
¹Department of Geology, University of Kerala, Thiruvananthapuram, 695581, India
²Department of Earth and Environmental Science, K.S.K.V. Kachchh University, Bhuj-Kachchh, 370001, India
³Department of Geological and Mining Engineering and Sciences, Michigan Technological University, Houghton, 49931, MI, United States
⁴Physical Research Laboratory, Ahmedabad, 380009, India

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Wang, Jin,¹Li , Detian,²Liu, Kun,¹Yan, Chunjie,²Qing, Gang,¹Wang, Chunyong
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology 43, 271 – 289 Link to Article [DOI 10.13922/j.cnki.cjvst.202210018]
¹Science and Technology on Vacuum Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou, 730000, China
²School of Mechanical Engineering and Automation, Northeastern University, Shenyang, 110819, China

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

^1,2Liu, Xianfeng et al. (>10)
Space Science Reviews 219, 43 Link to Article [DOI 10.1007/s11214-023-00987-7]
¹Key Laboratory of Space Active Opto-electronics Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences (CAS), Shanghai, 200083, China
²Key Laboratory of Lunar and Deep Space Exploration, National Astronomical Observatories, CAS, Beijing, 100101, China

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

¹Wang, Xu,¹Zhang, Guozhuo,¹Li, Angze,¹Wang, Yun,¹Cui, Han,¹Zhao, Weiqian,¹Qiu, Lirong
Spectrochimica Acta -Part B Atomic Spectroscopy 207, 106759 Link to Article [DOI 10.1016/j.sab.2023.106759]
¹MIIT Key Laboratory of Complex-filed Intelligent Exploration, School of Optics and Photonics, Beijing Institute of Technology, Beijing, 100081, China

We currently do not have a copyright agreement with this publisher and cannot display the abstract here

^1,2Amanda C. Stadermann,¹Jessica J. Barnes,³Timmons M. Erickson,²Tabb C. Prissel,⁴Zachary D. Michels
Journal of Geophysical Research (Planets) (in Press) Open Access Link to Article [https://doi.org/10.1029/2022JE007728]
¹Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721 USA
²Astromaterials Research and Exploration Science at NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX, 77058 USA
³Jacobs JETS at NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX, 77058 USA
⁴Department of Geosciences, University of Arizona, 1040 E 4th St, Tucson, AZ, 85721 USA
Published by arrangement with John Wiley & Sons

The magnesian suite (Mg-suite) of rocks record some of the earliest intrusive magmatism on the Moon. Studies of these Mg-suite rocks find they are plutonic or hypabyssal, formed typically kilometers under the lunar surface. Several models exist to explain the formation and evolution of the Mg-suite but distinguishing between hypotheses can be difficult given limited sample availability. The global extent of Mg-suite magmatism remains in debate and is key to constraining models of early secondary crust building. In this study, we present magnesian clasts within Apollo impact melt rock 68815. These clasts contain olivine, plagioclase, with minor amounts of Mg-Al-spinel and pyroxene similar to spinel troctolites of the Mg-suite, but they lack plutonic textures. We provide evidence that some of the clasts may be of extrusive volcanic origin akin to terrestrial komatiites while others might represent crystalline impact melts. There exists a large breadth of evidence for Mg-suite intrusives, whereas here we present possible evidence of Mg-rich volcanic counterparts. If valid, this would broaden the known diversity of lunar volcanism during the initial stages of secondary crust building. We anticipate this finding to provide a greater constraint onto models of Mg-suite ascent and emplacement, which only currently consider intrusive magmatism, as well as a renewed motivation to examine impact melt breccias for rare and understudied lithologies. Future trace element studies or radiometric dating could be used to further interrogate the connections of these clasts to the Mg-suite.

¹Robert M. Hazen et al. (>10)
Journal of Geophysical Research (Planets) (in Press) Link to Article [https://doi.org/10.1029/2023JE007865]
¹Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, 20015 USA
Published by arrangement with John Wiley & Sons

A systematic survey of 161 known and postulated minerals originating on Mars points to 20 different mineral-forming processes (paragenetic modes), which are a subset of formation modes observed on Earth. The earliest martian minerals, as on Earth, were primary phases from mafic igneous rocks and their ultramafic cumulates. Subsequent primary igneous minerals were associated with products of limited fractional crystallization, including alkaline and quartz-normative lithologies. Significant mineral diversification occurred via precipitation of primary phases from aqueous and atmospheric fluids, including authigenesis, hydrothermal and cryogenic precipitation, and evaporites, including freeze drying during eras of low atmospheric pressures. In particular, hydrothermal mineral formation associated with both volcanic fluids and sustained hydrothermal activity in impact fracture zones may have triggered significant mineral diversification, though as yet undocumented. At least 65 such primary minerals have been identified by flown missions to Mars and from martian meteorites. A host of secondary martian minerals were produced by near-surface processes related to water/rock interactions, including hydration/dehydration, oxidation/reduction, serpentinization, metasomatism, and a variety of diagenetic alterations. Additional mineral diversity resulted from metamorphic events, including thermal and shock metamorphism, lightning, and bolide impacts. However, several dominant sources of mineral diversity on Earth, including: (1) extensive fluid/rock interactions and element concentration associated with plate tectonics; (2) high-pressure regional metamorphism associated with plate tectonics; and (3) biologically mediated mineralization—are not known to be in play on Mars. Consequently, we estimate the total mineral diversity of Mars to be an order of magnitude smaller than on Earth.

¹Michael S. Phillips,¹Scott L. Murchie,¹Frank P. Seelos,¹Katie M. Hancock,^1,2Christina Selby,¹Ryan T. Poffenbarger,¹David C. Stephens,^1,3Maia Kawamura
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2023.115712]
¹The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
²MAXAR Technologies, Arlington, VA, USA
³Department of Physics and Astronomy, Dartmouth College, Hanover, NH, USA
Copyright Elsevier

The CRISM instrument on MRO collected visible-infrared hyperspectral mapping data (HSP; 180 m/pixel, 262 spectral channels covering 365 to 3937 nm) that covered ∼39% of Mars. Here we present results from a new processing pipeline for these data that produces 5° x 5° hyperspectral mapping tiled mosaics that overlap the coverage of recently released multispectral map tile products (version 4 Multispectral Reduced Data Records, MRDRs; 180 m/pixel, 72 spectral channels). These data enable regional investigations into compositional variations that require high spectral resolution or wavelengths not included in MRDRs. In addition to standard processing techniques available in the CRISM Analysis Toolkit (CAT), the pipeline includes a new correction for systematic discrepancies in radiometric calibration between CRISM observing modes, an improved filtering algorithm to remediate noise, and a technique to correct for differences in radiometry among data strips that arise from differences in photometric and atmospheric conditions. Demonstration hyperspectral mapping tiles covering the Mawrth Vallis region were developed and compared with MRDRs and high spatial resolution hyperspectral targeted observations. The new processing pipeline shows an improvement in data quality over standard processing using CAT utilities. Compared to targeted observations (18 or 36 m/pixel, 545 spectral channels), hyperspectral mapping tile mosaics reveal compositional information across a much greater spatial extent at the expense of 5–10 times coarser spatial resolution. In addition, the hyperspectral mapping tile mosaics reveal greater compositional detail in both the spatial and spectral dimensions compared to MRDRs, but with sparser spatial coverage. Sample hyperspectral mapping tile mosaics over the Mawrth Vallis region reveal hydrated silica, Al-bearing smectite, Fe/Mg-bearing smectite, and mixed clays, consistent with compositions previously reported in the literature.

^1,2Piers Koefoed,³Jean-Alix Barrat,^1,4Olga Pravdivtseva,⁵Conel M. O’D. Alexander,^1,2Katharina Lodders,^1,4Ryan Ogliore,^1,2Kun Wang 王昆
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2023.07.025]
¹McDonnell Center for the Space Sciences, Washington University in St. Louis, St. Louis, Missouri, 63130, USA
²Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, 63130, USA
³Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, CNRS UMS 3113, F-29280 Plouzané, France
⁴Department of Physics, Washington University in St. Louis, St. Louis, Missouri, 63130, USA
⁵Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
Copyright Elsevier

The isotopic analysis of moderately volatile elements such as K have gained significant interest in recent years as they possess the potential to help us better understand solar system formation. Even so, the precise K isotopic composition of CI chondrites, the most chemically primitive chondrite, has remained elusive. As the K elemental composition of CI chondrites matches well with the solar photosphere, it is possible that their K isotopic composition represents the solar system initial value. Here, we investigate the CI chondrite K isotopic composition in order to determine the precise CI chondrite, and thus possibly solar system initial, δ41K value. In addition, we investigate the K isotope compositions of several other chondrite groups, evaluate all available chondrite K isotope data together, and use these data along with data from a range of other isotope systems to assess if nucleosynthetic variations, volatility related processes, or parent body processes can best explain the range of isotope variations. The δ41K composition of all nine CI chondrite pieces analyzed in this study show limited variation, ranging from −0.29‰ to −0.17‰. When combined with the previous CI analysis, an overall mean CI δ41K value of −0.21 ± 0.05‰ (2SE) is obtained. This K isotope composition is distinct from the Bulk Silicate Earth value of −0.43 ± 0.17‰ (2SD), heavier than almost all other chondrite groups, and may represent the solar system initial K isotope composition. When comparing all chondrites broadly, ordinary chondrites show the lightest mean K isotope composition of −0.76 ± 0.06‰ (H = −0.71 ± 0.12‰, L = −0.77 ± 0.04‰, LL = −0.81 ± 0.12‰), enstatite chondrites the middle composition of −0.39 ± 0.11‰ (EH = −0.34 ± 0.05‰, EL = −0.45 ± 0.20‰), and carbonaceous chondrites the heaviest composition of −0.31 ± 0.08‰. For the carbonaceous chondrite groups CK (−0.42 ± 0.11‰), CR (−0.46 ± 0.05‰), and CV (−0.38 ± 0.07‰) chondrites show lighter δ41K compositions compared to CO (−0.20 ± 0.10‰), CM (−0.23 ± 0.11‰), and CI (−0.21 ± 0.05‰) chondrites. When these K isotope group averages are compared against the averages for other mass-dependent moderately volatile element isotope systems (δ87Rb, δ66Zn, δ71Ga, δ128Te) and mass-independent isotope systems (ε54Cr, ε64Ni, ε50Ti, Δ17O, ε40K, and ε66Zn,), a range of correlations are observed. Across all chondrite groups δ41K shows correlations with δ87Rb, δ66Zn, and δ71Ga, and correlations with ε54Cr, ε64Ni, ε50Ti, ε40K, and ε66Zn. When comparing the CCs only, correlations are observed between δ41K and all four of the other moderately volatile elements assessed, while the mass-independent isotope systems show no strong correlations. Regarding the K isotope variations, these observations, along with other textural and chemical data, can be best explained by inherited isotopic variations form different precursor reservoirs (the cause of which is difficult to conclusively determine, though most likely related to the NC-CC dichotomy), and volatility related fractionation processes for the carbonaceous chondrite groups (most likely due to component mixing).