¹Vasilij G. Chiorny,^1,2Vasilij G. Shevchenko,^1,2Ivan G. Slyusarev,^1,2Olga I. Mikhalchenko,^1,3Yurij N. Krugly,³Dagmara Oszkiewicz
Planetary and Space Science (in Press) Open Access Link to Article [https://doi.org/10.1016/j.pss.2023.105779]
¹Institute of Astronomy of V.N. Karazin Kharkiv National University, Kharkiv 61022, Sumska Str. 35, Ukraine
²Department of Astronomy and Space Informatics of V.N. Karazin Kharkiv National University, Kharkiv 61022, 4 Svobody Sq., Ukraine
³Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University, Słoneczna 36, 60-286 Poznan, Poland
Copyright Elsevier

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^1,2V. Santiago Quinteros,³Thomas Dylan Mikesell,⁴Griffiths Luke,¹X. Jerves Alex
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2023.115812]
¹Advanced Modelling, Norwegian Geotechnical Institute, Oslo, Norway
²Department of Civil Engineering and Energy Technology, Oslo Metropolitan University, Norway
³Remote Sensing and Geophysics, Norwegian Geotechnical Institute, Oslo, Norway
⁴Integrated Geotechnology, Norwegian Geotechnical Institute, Oslo, Norway
Copyright Elsevier

A comprehensive program of geotechnical index tests performed on two regolith simulants, namely LHS-1 and LMS-1, are presented and discussed in this study. The index tests included a 2D analysis of particles shapes and measurements of grain density, particle size distribution, plastic and liquid limit, thermal conductivity, and maximum and minimum dry density. The detailed testing methodologies are provided, and their results are discussed and compared with data available in the literature from similar tests on the same regolith simulants. Additionally, a thorough analysis of the data in contrast with data of lunar soils is presented. The observed spread on the index tests results is explained by the indiscriminate use of different procedures, regolith mass, and methodologies across different laboratories and highlight the importance and urgency for planetary scientist to agree on best practices in geotechnical testing of regolith and extra-terrestrial simulants.

¹Kierra Wilk,²Janice L. Bishop,³Catherine M. Weitz,⁴Mario Parente,⁴Arun M. Saranathan,^4,5Yuki Itoh,⁶Christoph Gross,⁷Jessica Flahaut,⁵Frank Seelos
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2023.115800]
¹Brown University (Providence, RI)
²SETI Institute & NASA-Ames (Mountain View, CA)
³Planetary Science Institute (Tucson, AZ)
⁴University of Massachusetts at Amherst (Amherst, MA)
⁵Johns Hopkins University Applied Physics Lab (Laurel, MD)
⁶Free University of Berlin (Berlin, Germany)
⁷CRPG, CNRS/Université de Lorraine (Vandœuvre-lès-Nancy, France)
Copyright Elsevier

Intriguing outcrops in Ius Chasma provide a window into past aqueous processes in Valles Marineris, Mars. Hydrous sulfate minerals are abundant throughout this region, but one area in Ius Chasma includes phyllosilicates, opal, and additional materials with unusual spectral features. This study at Geryon Montes, an east-west horst that divides Ius Chasma into a northern and southern canyon, exploits recent advances in image calibration and feature extraction techniques for analysis of hyperspectral images acquired by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM). Specifically, a unique spectral “doublet” feature with absorptions at 2.21–2.23 and 2.26–2.28 μm is isolated at the border of phyllosilicate-bearing and sulfate-bearing regions in Ius Chasma and surveyed to characterize outcrops that may represent a changing climate on Mars. We document and map three distinct forms of this “doublet” material in relation to phyllosilicates and opal. Analyses of compositional maps derived from CRISM overlain on High Resolution Stereo Camera (HRSC) and High Resolution Imaging Science Experiment (HiRISE) imagery has revealed the presence of these hydrated outcrops along the wall rocks below a breach in the Geryon Montes, bordering a canyon containing abundant hydrated sulfates. Our investigation supports formation of these unique alteration phases through acid alteration of ancient smectites in the wall rock as the sulfate brine overflowed the south canyon of Ius Chasma at the breach in Geryon Montes and penetrated the deeper northern canyon.

¹Shaofan Che,¹Kenneth J. Domanik,¹Yao-Jen Chang,^1,2Thomas J. Zega
Earth and Planetary Science Letters 621, 118374 Link to Article [https://doi.org/10.1016/j.epsl.2023.118374]
¹Lunar and Planetary Laboratory, University of Arizona, Tucson AZ, United States of America
²Department of Materials Science and Engineering, University of Arizona, Tucson AZ, United States of America
Copyright Elsevier

The important role that aqueous fluids played during the evolution of carbonaceous chondrites (CCs) and the carbonaceous asteroids that they derive from is well documented. In comparison, our understanding of how such fluids affected ordinary chondrites (OCs) and their S-type asteroid parent bodies is less mature in part due to the intense thermal metamorphism that overprinted the records of alteration. Further, that only a small suite of unequilibrated OCs shows evidence of hydration hinders our understanding of the role that fluids played in the evolution of OCs and S-type asteroids. Here we report a microstructural analysis on halite (NaCl) and sphalerite (ZnS) in Sidi El Habib 001 (SEH 001), a H5 OC that provides new insights into the role of fluids on the OC parent bodies. Our data reveal that halite contains alteration relicts of submicron silicates, and that widespread sphalerite spatially correlates with halite. This relationship suggests that sphalerite formed from the same hydrothermal fluid that precipitated halite, consistent with experimental and theoretical work showing that Cl-rich fluids induce complexation of Zn and significantly enhance its mobility. We hypothesize that Cl-rich hydrothermal fluids resulted from melting of locally concentrated HCl hydrate, which produced acidic fluids capable of dissolving chondritic mineral phases. The pH of the fluid presumably varied on a micrometer scale due to different rates of hydrolysis reactions as a function of grain size, as illustrated by the absence of halite in SEH 001 chondrules. Such a fluid-alteration model is attractive because it offers a reasonable explanation for the limited and heterogeneous alteration effects in OCs.

^1,2,3Benjamin E. Cohen,^1,4Darren F. Mark,⁵William S. Cassata,³Lara M. Kalnins,²Martin R. Lee,^2,6Caroline L. Smith,^7,8David L. Shuster
Earth and Planetary Science Letters 621, 118373 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2023.118373]
¹Scottish Universities Environmental Research Centre (SUERC), East Kilbride, UK
²School of Geographical and Earth Sciences, University of Glasgow, UK
³School of GeoSciences, University of Edinburgh, UK
⁴Department of Earth and Environmental Sciences, University of St Andrews, UK
⁵Lawrence Livermore National Laboratory, CA, USA
⁶Department of Earth Sciences, The Natural History Museum, London, UK
⁷Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
⁸Berkeley Geochronology Center, Berkeley, CA, USA
Copyright Elsevier

The shergottites are the most abundant and diverse group of Martian meteorites and provide unique insights into the mafic volcanic and igneous history of Mars. Their ages, however, remain a source of debate. Different radioisotopic chronometers, including 40Ar/39Ar, have yielded discordant ages, leading to conflicting interpretations on whether the shergottites originate from young (mostly <700 Ma) or ancient (>4,000 Ma) Martian volcanoes. To address this issue, we have undertaken an 40Ar/39Ar investigation of seven shergottite meteorites utilizing an innovative approach to correcting data for cosmogenic isotope production and resolution of initial trapped components which, crucially, do not require assumptions concerning the sample’s geologic context. Our data yield statistically robust 40Ar/39Ar isochron ages ranging from 161 ± 9 Ma to 540 ± 63 Ma (2σ), synchronous with the U-Pb, Rb-Sr, and Sm-Nd ages for the respective meteorites. These data indicate that, despite experiencing shock metamorphism, the shergottites were sourced from the youngest volcanoes on Mars.

^1,2L. Folco,³P. Rochette,^1,2M. D’Orazio,^1,2M. Masotta
Geochimica et Cosmochimica Acta (in Press) Open Aceess Link to Article
[https://doi.org/10.1016/j.gca.2023.09.018]
¹Dipartimento di Scienze della Terra, Università di Pisa, Via S. Maria 53, Pisa, Italy
²CISUP, Centro per la Integrazione della Strumentazione dell’Università di Pisa, Lungarno Pacinotti, Pisa, Italy
³Aix-Marseille Université, CNRS, IRD, INRAE, UM 34 CEREGE, Aix-en-Provence, France
Copyright Elsevier

In the Earth’s crust, Ni is generally concentrated in mafic and ultramafic rocks and is coupled with Mg in Mg-olivine, Mg-pyroxene and spinel. Whether the Ni-rich, and in general, the mafic component of Australasian tektites and microtektites is terrestrial or meteoritic is still debated. To test the origin of the Ni-rich component, we studied the Ni versus Mg distribution in a large geochemical database of Australasian tektites (n = 208) and microtektites (n = 238) from the literature. Nickel contents of up to 428 µg/g in tektites and 678 µg/g in microtektites covary with Mg in tektites and in most (∼85%) of the microtektites defining a mixing trend between crustal and chondritic values, thereby documenting the chondritic origin of the Ni-rich component in Australasian tektites/microtektites. Mixing calculations indicate up to 4% and up to 6% by weight chondritic component in tektites and microtektites, respectively. A possible mafic component of terrestrial origin is observed in a minority of tektite and microtektite specimens. This finding is consistent with previous works suggesting a possible occurrence of a chondritic signature in high-Ni tektites, based on the study of highly siderophile elements and Os isotopes, and high-Ni microtektites, based on Ni, Co, and Cr ratios. The combined geochemical and isotopic analysis of high-Ni tektites and microtektites in collections worldwide may thus reveal the chondritic impactor type that generated one of the presumably largest impacts in the Cenozoic.

Linxi Li, Hejiu Hui, Sen Hu, Hao Wang, Wei Yang, Yi Chen, Shitou Wu, Lixin Gu, Lihui Jia, Fuyuan Wu
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14072]
Published by arrangement with John Wiley & Sons

The regolith samples returned by the Chang’E-5 mission (CE-5) contain the youngest radiometrically dated mare basaltic clasts, which provide an opportunity to elucidate the magmatic activities on the Moon during the late Eratosthenian. In this study, detailed petrographic observations and comprehensive geochemical analyses were performed on the CE-5 basaltic clasts. The major element concentrations in individual plagioclase grain of the CE-5 basalts may vary slightly from core to rim, whereas pyroxene has clear chemical zonation. The crystallization sequence of the CE-5 mare basalts was determined using petrographic and geochemical relations in the basaltic clasts. In addition, both fractional crystallization (FC) and assimilation and fractional crystallization models were applied to simulate the chemical evolution of melt equilibrated with plagioclase in CE-5 basalts. Our results reveal that the melt had a TiO₂ content of ~3 wt% and an Mg# of ~45 at the onset of plagioclase crystallization, suggesting a low-Ti parental melt of the CE-5 basalts. The relatively high FeO content (>14.5 wt%) in melt equilibrated with plagioclase could have resulted in extensive crystallization of ilmenite, unlike in Apollo low-Ti basalts. Furthermore, our calculations showed that the geochemical evolution of CE-5 basaltic melt could not have occurred in a closed system. On the contrary, the CE-5 basalts could have assimilated mineral, rock, and glass fragments that have higher concentrations of KREEP elements (potassium, rare earth elements, and phosphorus) in the regolith during magma flow on the Moon’s surface. The presence of the KREEP signature in the CE-5 basalts is consistent with literature remote sensing data obtained from the CE-5 landing site. These KREEP-bearing fragments could originate from KREEP basaltic melts that may have been emplaced at the landing site earlier than the CE-5 basalts.

Alexander N. Krot, Kazuhide Nagashima, Marina A. Ivanova, Dante Lauretta, Guy Libourel, Brandon C. Johnson, Frank E. Brenker, Viktoria Hoffman, Martin Bizzarro
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14072]
Published by arrangement with John Wiley & Sons

The CB (Bencubbin-like) metal-rich carbonaceous chondrites are subdivided into the CB_aand CB_b subgroups. The CB_a chondrites are composed predominantly of ~cm-sized skeletal olivine chondrules and unzoned Fe,Ni-metal ± troilite nodules. The CB_bchondrites are finer grained than the CB_as and consist of chemically zoned and unzoned Fe,Ni-metal grains, Fe,Ni-metal ± troilite nodules, cryptocrystalline and skeletal olivine chondrules, and rare refractory inclusions. Both subgroups contain exceptionally rare porphyritic chondrules and no interchondrule fine-grained matrix, and are interpreted as the products of a gas–melt impact plume formed by a high-velocity collision between differentiated planetesimals about 4562 Ma. The anomalous metal-rich carbonaceous chondrites, Fountain Hills and Sierra Gorda 013 (SG 013), have bulk oxygen isotopic compositions similar to those of other CBs but contain coarse-grained igneous clasts/porphyritic chondrule-like objects composed of olivine, low-Ca-pyroxene, and minor plagioclase and high-Ca pyroxene as well as barred olivine and skeletal olivine chondrules. Cryptocrystalline chondrules, zoned Fe,Ni-metal grains, and interchondrule fine-grained matrix are absent. In SG 013, Fe,Ni-metal (~80 vol%) occurs as several mm-sized nodules; magnesiochromite (Mg-chromite) is accessory; daubréelite and schreibersite are minor; troilite is absent. In Fountain Hills, Fe,Ni-metal (~25 vol%) is dispersed between chondrules and silicate clasts; chromite and sulfides are absent. In addition to a dominant chondritic lithology, SG 013 contains a chondrule-free lithology composed of Fe,Ni-metal nodules (~25 vol%), coarse-grained olivine and low-Ca pyroxene, interstitial high-Ca pyroxene and anorthitic plagioclase, and Mg-chromite. Here, we report on oxygen isotopic compositions of olivine, low-Ca pyroxene, and ±Mg-chromite in Fountain Hills and both lithologies of SG 013 measured in situ using an ion microprobe. Oxygen isotope compositions of olivine, low-Ca pyroxene, and Mg-chromite in these meteorites are similar to those of magnesian non-porphyritic chondrules in CB_aand CB_b chondrites: on a three-isotope oxygen diagram (δ¹⁷O vs. δ¹⁸O), they plot close to a slope-1 (primitive chondrule mineral) line and have a very narrow range of Δ¹⁷O (=δ¹⁷O–0.52 × δ¹⁸O) values, −2.5 ± 0.9‰ (avr ± 2SD). No isotopically distinct relict grains have been identified in porphyritic chondrule-like objects. We suggest that magnesian non-porphyritic (barred olivine, skeletal olivine, cryptocrystalline) chondrules in the CB_as, CB_bs, and porphyritic chondrule-like objects in SG 013 and Fountain Hills formed in different zones of the CB impact plume characterized by variable pressure, temperature, cooling rates, and redox conditions. The achondritic lithology in SG 013 represents fragments of one of the colliding bodies and therefore one of the CB chondrule precursors. Fountain Hills was subsequently modified by impact melting; Fe,Ni-metal and sulfides were partially lost during this process.

Christian Zeeden^a,b, Jacques Laskar^a, David De Vleeschouwer^d, Damien Pas^e, Anne-Christine Da Silva^c
Earth and Planetary Science Letters (in Press) Link to Article [https://doi.org/10.1016/j.epsl.2023.118348]
^aIMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, 75014 Paris, France
^bLIAG – Leibniz Institute for Applied Geophysics, Stilleweg 2, 30655 Hannover, Germany
^cPétrologie sédimentaire, B20, Allée du Six Août, 12, Quartier Agora, Liège University, Sart Tilman, 4000 Liège, Belgium
^dInstitute of Geology and Paleontology, Westfälische Wilhelms-Universität (WWU) Münster, Corrensstr 24, 48149 Münster, Germany
^eInstitute of Earth Sciences (ISTE), University of Lausanne, CH-1015 Lausanne, Switzerland
Copyright : Elsevier

Astronomical insolation forcing plays an important role in pacing Earth’s climate history, including paleoclimate dynamics, and its imprint can be seen in various geoarchives. Its signature is often evident through typical rhythmic patterns in sediments. The detailed study of those patterns led to a better understanding of orbital climate forcing, while also providing more precise constraints on the geological time scale. Due to the tidal evolution in the Earth-Moon system, the precession and obliquity periods get shorter when going back in time while the main eccentricity 405 kyr period remains stable. While several astrophysical models describe the evolution of the length of precession- and obliquity cycles, few reliable and quantitative geological information from tidalitesand astrochronology are available.

To better constrain these key astronomical parameters in the distant past, we calculate precession and obliquity properties for the Devonian (∼420-360 million years before present) as reconstructed from a suite of geological datasets. Our results show the period of precession to be 19.4-16.1 kyr, and the dominant p+s3 obliquity period to be 29.50±0.46 long. These findings are compared with and support the presence of oceanic tidal resonances at 300 and 540 Ma, as shown in the recent AstroGeo22 model of the Earth-Moon evolution of (Farhat et al., 2022).

Jonas PAPE¹, Bidong ZHANG², Fridolin SPITZER³, Alan E. RUBIN², andThorsten KLEINE³
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14075]
¹Institut für Planetologie, University of Münster, Münster, Germany
²Department of Earth, Planetary & Space Sciences, University of California, Los Angeles, California, USA
³Max Planck Institute for Solar System Research, Göttingen, Germany
Published by arrangement with John Wiley & Sons

Complex interelement trends among magmatic IIIF iron meteorites are difficult to explain by fractional crystallization and have raised uncertainty about their genetic relationships. Nucleosynthetic Mo isotope anomalies provide a powerful tool to assess if individual IIIF irons are related to each other. However, while trace element data are available for all nine IIIF irons, Mo isotopic data are limited to three samples. We present Mo isotopic data for all but one IIIF irons that help assess the genetic relationships among these irons, together with new Mo and W isotopic data for Fitzwater Pass (classified IIIF), and the Zinder pallasite (for which a cogenetic link with IIIF irons has been proposed). After correction for cosmic-ray exposure, the Mo isotopic compositions of the IIIF irons are identical within uncertainty and confirm their belonging to carbonaceous chondrite (CC)-type meteorites. The mean Mo isotopic composition of group IIIF overlaps those groups IIF and IID, but a common parent body for these groups is ruled out based on distinct trace element systematics. The new Mo isotopic data do not argue against a single parent body for the IIIF irons, and suggest a close genetic link among these samples. In contrast, Fitzwater Pass has distinct Mo and W isotopic compositions, identical to those of some non-magmatic IAB irons. The Mo and W isotope data for Zinder indicate that this meteorite is not related to IIIF irons, but belongs to the non-carbonaceous (NC) type and has the same Mo and W isotopic composition as main-group pallasites.