¹Haijun Cao,¹Jian Chen,¹Chengxiang Yin,^1,2Xiaohui Fu,^1,2Zongcheng Ling,³Xiaochao Che
Meteoritics & Planetary Science (in Presss) Link to Article [https://doi.org/10.1111/maps.14131]
¹Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai, Shandong, China
²CAS Center for Excellence in Comparative Planetology, Chinese Academy of Sciences, Hefei, China
³Beijing SHRIMP Center, Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China
Published by arrangement with John Wiley & Sons

Northwest Africa (NWA) 7611/10480 are lunar regolith breccia meteorites, composed of mineral fragments and various clasts including mare basalts, volcanic glasses, gabbroic lithologies, and a diverse variety of highland materials (ferroan anorthosite, Mg-suite, magnesian anorthosite, and alkali suite rocks) as well as different subvarieties of impact melt breccia. The Apollo two-component mixing model calculation reveals that the NWA 7611 source region contains 58 wt% mare materials and 42 wt% highland components, but the estimated mare components in NWA 10480 have a higher abundance (66 wt%). The predominantly very low-Ti (VLT) composition in both fine-grained basaltic and coarse-grained gabbroic lithologies indicates a provenance associated with a thick lava flow or a single magmatic system. The co-occurrence of zoning patterns and fine-scale exsolution lamellae in pyroxene debris supports a cryptomare deposit as the best candidate source. Phosphate Pb–Pb ages in matrix fragments, impact melt breccia, and basaltic clast indicate that the breccia NWA 7611 records geological events spanning approximately 4305–3769 Ma, which is consistent with the ages of ancient lunar VLT volcanism and the products of basin-forming impacts on the lunar nearside. The youngest reset age at ~3.2 Ga is potentially related to the strong shock lithification process of breccia NWA 7611. Moreover, the similar petrology, texture, geochemistry, cosmic-ray exposure data, and crystallization ages support that basaltic component in Yamato (Y)-793274, and Queen Alexandra Range (QUE) 94281, NWA 4884, and NWA 7611 clan came from the same basalt flow.

¹M. H. Leili,¹H. Chennaoui Aoudjehane,²B. Devouard,²P. Rochette,²J. Gattacceca,³L. Folco,³M. Gemelli,⁴I. Baziotis
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14119]
¹GAIA Laboratory, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Casablanca, Morocco
²France Aix Marseille University, CNRS, Coll France, IRD, INRAE, CEREGE, Aix-en-Provence, France
³Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
⁴Laboratory of Mineralogy and Geology, Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Athens, Greece
Published by arrangement with John Wiley & Sons

In this work, we investigate macroscopic characteristics, magnetic susceptibility, mineralogy, and mineral composition of Al Haggounia 001. The samples were collected during eight field missions in the period between 2015 and 2019. In the strewn field of about 65 km in length, the specimens are found either on the surface or shallowly buried in loose sediments, which rules out the previous suggestions that this meteorite is a fossil meteorite. Macroscopically, the samples exhibit three major lithologies with various colors, porosities, and distributions of oxidized veins. The data obtained using transmitted and reflected light microscopy, scanning electron microscopy, and electron microprobe analysis confirm the macroscopic observations and show a heterogenous distribution of silicates and metal sulfides. Al Haggounia 001 is composed of enstatite, plagioclase, kamacite, taenite, schreibersite, daubreelite, troilite, graphite, sinoite, and silica polymorphs. We identified a new type of chondrules that are flattened and composed of rods of albite and enstatite, as well as elongated nodules of metal and sulfides, in addition to compression fractures in the form of subparallel veinlets. These features presumably reflect the deformation caused by shock. The magnetic susceptibility of Al Haggounia 001 (4.39 ± 0.20) is much lower than that of usual EH (5.48 ± 0.16) and EL (5.46 ± 0.04) chondrites but is in the range of E finds (5.05 ± 0.43). The thermomagnetic and hysteresis measurements are controlled by type, size, distribution of metal-sulfide nodules, arrangement of oxyhydroxide veins, and weathering. Al Haggounia 001 is an anomalous meteorite with a polymict nature. It records multiple events revealing its unique origin which expends the groups of enstatite chondrites and provides insights into the complex formation and evolution history of their parent body.

¹Matthieu Clog,²Paula Lindgren,³Sevasti Modestou,¹Alex McDonald,¹Andrew Tait,¹Terry Donnelly,¹Darren Mark,⁴Martin Lee
Geochimica et Cosmochimica Acta (in Press) Open Access Link to Article [https://doi.org/10.1016/j.gca.2024.01.023]
¹Scottish Universities Environmental Research Centre, Glasgow, United Kingdom
²Geological Survey of Sweden, Lund, Sweden
³University of Northumbria, Newcastle upon Tyne, United Kingdom
⁴School of Geographical and Earth Sciences, University of Glasgow, Glasgow, United Kingdom
Copyright Elsevier

The CM carbonaceous chondrites are key archives for understanding the earliest history of the solar system. Their C-complex asteroid parent body(ies) underwent aqueous alteration, among the products of which are carbonate minerals that can faithfully record the conditions of their formation. In this study we report carbon, triple oxygen and clumped isotope compositions of carbonates in six CM chondrites which span a range in degrees of aqueous alteration (Allan Hills 83100, Cold Bokkeveld, LaPaz Icefield 031166, Lonewolf Nunataks 94101, Murchison, Scott Glacier 06043). Δ¹⁷O values range from -1 to -2.6‰ (±0.1), and where calcite and dolomite co-exist their Δ¹⁷O differ by 0.6 permil, suggesting precipitation from distinct fluids. Calculated crystallization temperatures range from 5 to 51⁰C for calcite (typically ±10⁰C) and 75 to 101(±15)⁰C for dolomite. The δ¹⁸O_VSMOW of the aqueous fluids from which they formed ranges from -6.6 to 2.3‰, with no relationship to the δ¹³C of carbonates. As the population of carbonates in any one CM chondrite can include multiple generations of grains that formed at different conditions, these values represent the mode of the temperature of carbonate formation for each meteorite. We observe that in the more altered meteorites carbonate Δ¹⁷O values are lower and formation temperatures are higher. These correlations are consistent with aqueous alteration of the CM chondrites being a prograde reaction whereby the hotter fluids had undergone greater isotope exchange with the anhydrous matrix. Our data are broadly consistent with the closed system model for water/rock interaction, but carbonate mineral formation in the latter stages of aqueous alteration may be linked to fluid movement via fractures.

¹T. Le Pivert-Jolivet et al. (>10)
Nature Astronomy 7, 1445-1453 Link to Article [DOI https://doi.org/10.1038/s41550-023-02092-9]
¹Institut d’Astrophysique Spatiale, Université Paris-Saclay, CNRS, Orsay, France

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

^1,2Tara S. Hayden,^1,3Thomas J. Barrett,¹Mahesh Anand,⁴Martin J. Whitehouse,
⁴Heejin Jeon,¹Xuchao Zhao,¹Ian A. Franchi
Nature Astronomy (in Press) Open Access Link to Article [DOI https://doi.org/10.1038/s41550-023-02185-5]
¹School of Physical Sciences, The Open University, Milton Keynes, UK
²Department of Earth Sciences, University of Western Ontario, London, Ontario, Canada
³Center for Lunar Science and Exploration, Lunar and Planetary Institute, Houston, TX, USA
⁴Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden

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

¹Qinting Jiang,¹Shun-ichiro Karato,^2,3Thilo Bissbort,³Varvara Foteinou
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2024.115958]
¹Department of Earth and Planetary Science, Yale University, 210 Whitney Avenue, New Haven, CT 06520, USA
²Department of Earth and Environmental Sciences, Ludwig-Maximilians-University, Theresienstr. 41, 80333 Munich, Germany
³Central Unit for Ionbeams and Radionuclides RUBION, Ruhr-University Bochum, Universitätsstraße 150, 44801 Bochum, Germany
Copyright Elsevier

The solar wind is a possible source for hydrogen and other volatiles on planetary bodies. To better understand the role of the solar wind during the volatile acquisition of planetary materials, we conducted hydrogen implantation experiments on olivine, orthopyroxene, quartz single crystals. Depth profiles of hydrogen concentration after implantation are determined by the Nuclear Resonance Reaction Analysis. We find that energetic hydrogen particles penetrate into the sample and accumulate at a certain depth. The hydrogen concentration increases with the hydrogen fluence until a “saturation level” is attained. Hydrogen saturation level (e.g., ~10–20 at.% in olivine, equivalent to 0.5–1.2 wt%) far exceeds the equilibrium solubility in the bulk crystal at a similar thermodynamic condition (~10−22 wt%). The results of olivine show that the hydrogen penetration depth increases whereas the saturation level decreases (weakly) with the beam energy. Hydrogen saturation level also depends on the mineral species in the order: olivine > orthopyroxene > quartz. The experimental results can be applied to explain some observations on the high surface water content of some planetary bodies including Itokawa asteroid and the Moon. We also explore the possibility of hydrogenated dusts by the solar wind implantation as a source for water on terrestrial planets. We conclude that if all dusts were exposed to the solar wind and all implanted hydrogen were converted to water, then >10 ocean masses would have been acquired for Earth by ~100 years. However, the main part of the proto-planetary disk was not exposed to the solar wind and dusts could have been hydrogenated only when they were far from the equatorial plane of the disk. We discuss a possible mechanism to transport the hydrogenated dusts to the disk interior via turbulent mixing. Also, our experimental results and the mass dependence of the particle energies in the solar wind suggest that the D/H ratio of the dusts exposed to the solar wind will be higher than the solar wind value.

¹Zaicong Wang et al. (>10)
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2024.01.002]
¹State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
Copyright Elsevier

Sulfides are accessory phases in lunar rocks but are important for understanding lunar interior processes as well as impacts on the lunar surface. Whether or not the lunar mantle had achieved sulfide saturation during magma ocean evolution and displays homogeneous sulfur isotopes remains under debate. The Chang’e-5 (CE-5) mission returned young (2.0 Ga) basalts from a mare terrain in the northern Oceanus Procellarum. Here we study chemical and sulfur isotopic compositions (δ34SV-CDT) of sulfides from CE-5 basaltic fragments and combine them with δ34S of other young (3.1–3.0 Ga) lunar low-Ti basalt (NWA 10597 and NWA 4734) and gabbro meteorites (NWA 6950) to compare them with Apollo low-Ti and high-Ti mare basalts. The sulfides in basaltic fragments of CE-5 are troilites (FeS) with low abundances of Ni, Co, and Cu (e.g., Ni < 0.04 wt.% and Ni/Co < 0.3). Textures and chemical compositions indicate that most troilites are late-stage crystallization products from the highly evolved CE-5 basalts. Several troilites occur in the matrices of impactite clasts and are intergrown with Fe–Ni metal (12–36 wt.% Ni, Ni/Co of 12–39). These troilites are distinct from the major population of troilites with noticeably higher Ni abundances (mostly >0.2 wt.% with Ni/Co of 1–3) and reconcile with the addition of meteoritic materials into the impact melts.

The δ34SV-CDT of large troilite grains (>10 μm) from the CE-5 basaltic fragments and lunar meteorites were obtained by high-precision, high-spatial-resolution femtosecond laser ablation MC-ICP-MS which achieved external uncertainty (0.65‰, 2SD at 8-μm laser spots) like nano-SIMS. Sulfur degassing during surficial effusive lava flow likely led to a slight decrease in δ34S (by ∼1‰) for some basaltic fragments; however, such effects were limited to the scale of bulk rock samples, consistent with previous results. The mean δ34S of troilites in CE-5 basaltic fragments (0.35±0.25‰, 2SE, n = 45) is similar to those of ancient (3.8–3.1 Ga old) Apollo low-Ti and high-Ti mare basalts and the young gabbro cumulate NWA 6950 (0.56 ± 0.21‰, 2SE, n = 10). The paired NWA 10597 and NWA 4734 show consistent δ34S, lower than most values by ∼0.5‰. Current data thus indicate that most mantle sources of lunar basalts would be homogeneous for δ34S (0.6 ± 0.3 ‰) and minor regions may be different. The overall homogenous δ34S from different mantle sources with variably low sulfur content supports sulfide-undersaturated accumulation of the lunar magma ocean, which was inherited from strong volatile loss and evaporative fractionation during the formation of the Moon.

¹Zachary A. Torrano,¹Conel M.O’D. Alexander,¹Richard W. Carlson,²Jan Render,²Gregory A. Brennecka,¹Emma S. Bullock
Earth and Planetary Science Letters 627, Link to Article [https://doi.org/10.1016/j.epsl.2023.118551]
¹Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, United States
²Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
Copyright Elsevier

Amoeboid olivine aggregates (AOAs) are the most abundant type of refractory inclusions found in most carbonaceous chondrite groups. AOAs are thought to be genetically related to calcium-aluminum-rich inclusions (CAIs) and potential chondrule precursor components, although the precise physical and temporal details of AOA formation and their relationship to other chondritic components remain unclear. In this study, we measured the chromium and titanium isotopic compositions of eight AOAs from four different CV chondrites with the goal of evaluating potential genetic links between AOAs, CAIs, and chondrules. These are the first Cr and Ti isotopic data reported beyond a single AOA previously measured for Cr and a different single AOA previously measured for Ti. The results presented here show that the ε54Cr and ε50Ti isotopic compositions of AOAs are indistinguishable from those of CAIs, suggesting that AOAs and CAIs formed from a common region of the disk. We also demonstrate, based on the comparison of the Cr and Ti isotopic composition of AOAs to previously measured chondrules, that mixing between AOAs and an NC compositional endmember alone cannot fully explain the range of measured chondrule compositions. Although AOAs may have been important chondrule precursor components along with AOA olivine, CAIs, fragments of earlier generation chondrules, and fine-grained matrix material, this observation requires another currently unknown component to be involved in chondrule formation.

¹C. Maurel,¹J. Gattacceca,¹M. Uehara
Earth and Planetary Science Letters 627, 118559, Open Access Link to Article [https://doi.org/10.1016/j.epsl.2023.118559]
¹CNRS, Aix Marseille Univ, IRD, INRAE, CEREGE, Aix-en-Provence, France
Copyright Elsevier

The JAXA Hayabusa 2 mission returned 5.4 g of material from the C-type asteroid Ryugu. The Mn-Cr ages of dolomite in the returned samples indicate that Ryugu’s parent body experienced aqueous alteration sometimes between <1.8 and 6.8 Myr after CAI formation. Because this time range overlaps with the lifetime of the solar nebula, we investigate the possibility that magnetite and pyrrhotite, which are aqueous alteration products found in Ryugu samples, acquired a remanent magnetization reflecting the nebula field intensity. We analyze the intrinsic magnetic properties and paleomagnetic record of three Ryugu samples of 0.82, 0.97 and 21.87 mg. None of the samples exhibit a stable natural remanent magnetization. This indicates that the aqueous alteration of Ryugu’s parent body took place either in a field of a few µT, or in a very weak to null field. In the former scenario, the solar nebula field is the most likely magnetizing field, implying that aqueous alteration occurred before its dissipation, i.e., before ∼5 Myr after CAI formation. In the latter scenario, aqueous alteration must have occurred either after the dissipation of the nebula, or at an earlier epoch and a large heliocentric distance (> 5 au). The similarities between Ryugu samples and CI chondrites favor this second hypothesis. Our results contrast with another paleomagnetic study of two Ryugu samples, arguing for a paleofield intensity of 40 to 390 µT. Our interpretation of this discrepancy is that these samples were exposed to artificial magnetic fields (> mT) during preceding experiments. This highlights the importance of conducting, as much as possible, the paleomagnetic investigations of returned samples before any other experiment. We also demonstrate that the ratio of NRM over low-field magnetic susceptibility is a powerful, non-destructive indicator of magnetic contamination. We recommend measuring this ratio routinely before paleomagnetic investigations of meteorites and returned samples.

¹Matthias van Ginneken et al. (>10)
Earth and Planetary Science Letters 627, 118562 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2023.118562]
¹Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Ingram Building, Canterbury CT2 7NH, UK
Copyright Elsevier

Airbursts are estimated to be the most frequent and hazardous type of impact events. Yet, confirmation of these events are elusive, resulting in a major gap in the impact record of Earth. The recent discovery of igneous chondritic spherules produced during a new type of touchdown airburst 430 thousand years (kyr) ago over Antarctica, in which a projectile vapor jet interacts with the Antarctic ice sheet, provided the first trace of such an impact in the geological record. In terms of petrology and geochemistry, particles constituting the BIT-58 dust horizon, which was found in surface ice at near Allan Hills in Antarctica, are almost identical to those produced 430 kyr ago. We demonstrate here that BIT-58 particles were indeed formed during a touchdown event between 2.3 and 2.7 million years (Myr) ago. This represents the oldest record of an airburst on Earth identified to date. Slight geochemical differences with 430 kyr old airburst spherules provide additional constraints on spherule condensation in large airburst plumes. Finding confirmation of airbursts in the paleorecord can provide insight into the frequency of the most hazardous impacts and, thus, has implications for planetary defence.