^1,2Sen Hu, ^2,3Mahesh Anand, ²Ian A. Franchi, ²Xuchao Zhao, ^2,4Alice Stephant, ⁵Magali Bonifacie, ^1,6Huicun He, ¹Wei Yang, ¹Jialong Hao, ¹Yangting Lin
Earth and Planetary Science Letters 648, 119072 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2024.119072]
¹Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
²School of Physics Sciences, The Open University, Milton Keynes MK7 6AA, UK
³Department of Earth Sciences, The Natural History Museum, London, SW7 5BD, UK
⁴Istituto di Astrofisica e Planetologia Spaziali -INAF, Roma, Italy
⁵Institut de Physique du Globe de Paris, Université de Paris, CNRS, 75005 Paris, France
⁶College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
Copyright Elsevier

The chassignites and nakhlites could have co-magmatic origin but display distinct hydrogen and chlorine isotopic compositions, indicating that they may have experienced distinct hydrothermal activities on Mars. However, the details are not yet fully understood. Here, we performed H and Cl isotopic investigations on hydrous minerals (kaersutite and apatite) and glass-bearing melt inclusions from chassignite NWA 2737 to unravel the details of the hydrothermal events experienced by chassignites on Mars. Our results demonstrate that at least two hydrothermal events on Mars have been recorded in NWA 2737. A D- and 37Cl-rich martian crustal/underground fluid was added to the parent magma of NWA 2737 prior to the entrapment of melt inclusions and later interaction of the parent rock with a D-poor fluid, probably deriving from magma degassing. The notable high-δD values (up to 6239‰) of kaersutite in NWA 2737 are comparable with those recorded in younger shergottites, suggesting that the martian exchangeable water reservoir has retained a nearly constant δD value over the past 1.3

¹Mihail P. Petkov, ²Ryan P. Wilkerson, ³Gerald E. Voecks, ⁴Douglas L. Rickman, ⁵Jennifer E. Edmunson, ⁵Michael R. Effinger
Planetary and Space Science (in Press) Link to Article [https://doi.org/10.1016/j.pss.2024.105982]
¹SuprAEther LLC, La Crescenta, CA, 91214, USA
²Sigma-1: Fabrication Manufacturing Science, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
³NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, 91109, USA
⁴Jacobs Engineering, Inc., Huntsville, AL, 35812, USA
⁵NASA Marshall Space Flight Center, Huntsville, AL, 35812, USA

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

^1,2M. C. Nottingham,^1,3,4N. M. Curran,¹J. Pernet-Fisher,¹R. Burgess,¹I. A. Crawford,¹J. D. Gilmour,¹R. Tartèse,¹K. H. Joy
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.14244]
¹Department of Earth and Environmental Sciences, University of Manchester, Manchester, UK
²School of Geographical and Earth Sciences, Molema Building, University of Glasgow, Glasgow, G12 8QQ UK
³NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
⁴CRESST2/Catholic University of America, Washington, DC, USA
⁵School of Natural Sciences, Birkbeck College, University of London, London, UK
Published by arrangement with John Wiley & Sons

The Apollo 16 regolith breccia sample suite provides a record of lunar regolith formation from the basin-forming epoch (~3.9 Ga) through to a time of declining impactor flux (~2 Ga). These rocks have been characterized into three groups: the “ancient,” “young,” and “soil-like” regolith breccias on the basis of their petrographic characteristics, and, in the case of the “ancient” and “young” regolith breccias, noble gas inventory. This study investigates the as-yet unexamined noble gas records of the “soil-like” regolith breccias to understand more recent regolith evolution processes that occurred at the Apollo 16 landing site. The range of gas concentrations measured for each noble gas in these samples is comparable to those previously reported for the local Apollo 16 soils. The “soil-like” regolith breccias were found to be more gas rich than the gas poor “young” and “ancient” regolith breccias, consistent with them having formed from comparatively mature soil(s). Our results further confirm the scientific value of lunar regolith breccias and bulk regolith samples as probes of the impact history and the space environment of the lunar surface across a wide range of time.

¹O. Rüsch,¹B. Aussel
Journal of Geophysical Research (Planets) (in Press) Open Access Link to Article [https://doi.org/10.1029/2024JE008626]
¹Institut für Planetologie, Universität Münster, Münster, Germany
Published by arrangement with John Wiley & Sons

Rock abundances on the Moon represent both an opportunity to understand the history of the surface and of the regolith and a hazard to lander missions. While rock erasure by meteoroid bombardment is known to modify rock size˗frequency distributions, the interplay between rock erasure and rock exposure by impact cratering, and the resulting net rock abundance, is not known. Leveraging a coupling between modeling and optical imagery from the lunar orbit, we calculate new rock lifetimes that consider the specific shattering energy and the fragments produced by boulder shattering. We find differences between the estimated and expected specific shattering energy (Qs*), likely suggesting incomplete understanding of the scaling of the shattering energy with velocity and size. We find that the decrease in rock abundances with time on crater ejecta occurs faster than previous estimates based on thermal infrared data.

^1,2,3G. Nishiyama,³T. Morota,^2,3,4N. Namiki,³K. Inoue,³S. Sugita
Journal of Geophysical Research (Planets) (in Press) Open Access Link to Article [https://doi.org/10.1029/2023JE008034]
¹Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany
²National Astronomical Observatory of Japan, Mitaka, Japan
³Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
⁴The Graduate University for Advanced Studies, SOKENDAI, Hayama, Japan
Published by arrangement with John Wiley & Sons

Linear gravity anomalies (LGAs) on the Moon have been interpreted as ancient magmatic intrusions formed during the lunar expansion. The composition of such ancient subsurface intrusions may offer hints for the lunar thermodynamic state in the initial stage of lunar history. To pose a first compositional constraint on magmatism related to lunar expansion, this study analyzed the spectrum and gravity around craters on LGAs, such as Rowland, Roche, and Edison craters. Using reflectance spectra around the craters, we first surveyed non-mare basaltic exposures. To test the LGA excavation scenario as a possible origin of the discovered exposures, we then compared the Gravity Recovery and Interior Laboratory data and post-cratering gravity simulation with the iSALE shock physics code. Our spectral analysis reveals no basaltic exposure around the Rowland crater. Further, the observed termination of LGA at the crater rim contradicts the gravity simulation, which assumes that LGA predates the Rowland crater. These results suggest that LGA formation might postdate the Rowland formation and that lunar expansion lasted even after the Nectarian age. On the other hand, we found that both Roche and Edison craters possess basaltic exposures in their peripheries. Because the gravity reduction inside Roche crater can be reproduced in our simulation, the discovered basaltic exposures are possibly LGA materials ejected from these craters. The composition of those exposures shows that the LGA intrusions at the two locations are composed of low-titanium magma, indicating that ancient magma during the expansion did not contain ilmenite-rich melt, perhaps resulting from the low-ilmenite content of the ancient upper mantle.

¹Arthur Goodwin, ²Christian Schröder, ²Emily Bonsall, ^1,3Russell J. Garwood, ¹Romain Tartèse
Earth and Planetary Science Letters 647, 119055 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2024.119055]
¹Department of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PY, UK
²Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, UK
³Natural History Museum, London, UK
Copyright Elsevier

The martian meteorite Northwest Africa (NWA) 11220 and paired stones (notably NWA 7034) are the only group of meteorites that sample a clastic near-surface lithology from Mars. The stones have been recognized as an impact-reworked lithology subjected to an impact-induced hydrothermal system — comparable to the postulated history of Jezero Crater, currently being explored by the NASA Perseverance rover. By applying Mössbauer spectroscopy in combination with several in situ analytical techniques including Raman spectroscopy, FTIR spectroscopy, and NanoSIMS, we show that aliphatic carbon compounds dominate the inventory of insoluble indigenous carbon compounds within NWA 11220. Disordered carbon — present in ∼5 μm heterogeneous masses — is preferentially found within porosity where it adjoins the mineral surface of titano-magnetite. This relationship suggests catalytic surfaces have enabled Fischer–Tropsch (FT) synthesis of hydrocarbons. Our in situ micron-scale analytical study indicates that such methods can help determine the origin of organic material that exists in the near-surface martian regolith. Such multimodal approaches will be a key methodology for searching for traces of past life in future samples returned from Mars.

¹Shen, Laiquan,^1,2Zhao, Rui,^1,2Chang, Chao,^1,2Yu, Jihao,¹Xiao, Dongdong,^1,2,3Bai, Haiyang,^4,5Zou, Zhigang,^4,6Yang, Mengfei,^1,3,4Wang, Weihua
Nature Astronomy 8, 1110-1118 Link to Article [DOI https://doi.org/10.1038/s41550-024-02300-0]
¹Institute of Physics, Chinese Academy of Sciences, Beijing, China
²Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, China
³Songshan Lake Materials Laboratory, Dongguan, China
⁴Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing, China
⁵College of Engineering and Applied Sciences, Nanjing University, Nanjing, China
⁶China Academy of Space Technology, Beijing, China

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

¹Lucie Laize-Générat et al. (>10)
Geochimica et Cosmochimica Acta (in Press) Open Access Link to Article [https://doi.org/10.1016/j.gca.2024.10.001]
¹Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
Copyright Elsevier

Nitrogen, because of its abundance and variety of carrier phases, is a unique tracer of physico-chemical processes occurring throughout star and planet formations. The refractory organic matter is commonly considered as the main carrier of nitrogen in the most primitive objects of our Solar System. However, nitrogen in the form of ammonium (NH4+) was observed in the Ivuna-type carbonaceous (CI) chondrites Alais in 1834, and Orgueil just after its fall in 1864, as well as more recently on Ceres, comet 67P/Churyumov-Gerasimenko, and possibly on some asteroids. In the present study, we have measured the nitrogen content and isotopic composition in various nitrogen-bearing phases of several samples of the Orgueil meteorite, with different degrees of terrestrial weathering. Water-soluble NH4+ is present in Orgueil at a mean concentration of 0.07 ± 0.01 wt%, with a mean isotopic composition of δ15N = +72 ± 9 ‰ (14N/15N = 254 ± 2), confirming its extra-terrestrial origin. In the most terrestrially altered sample of Orgueil that we analysed, the isotopic composition is δ15N = +50 ± 12 ‰ (14N/15N = 259 ± 3). NH4+ is in species that are thermally stable up to 383 K, possibly ammonium inorganic/organic salts and ammoniated phyllosilicates. We also show that the nitrogen in Orgueil is distributed among the insoluble organic matter (IOM) (35 ± 5 %), ammonium (27 ± 5 %), and other minor water-soluble species (e.g., nitrate, amines etc.: < 6 %). The remaining nitrogen (34 ± 14 %) is mainly in an unidentified organic matter (UOM), which may be IOM lost during its extraction and/or acid hydrolysable functional groups bounded to the IOM and/or organic nitrogen trapped within minerals. The three main carriers of nitrogen in Orgueil have δ15N (and 14N/15N) values of + 32 ± 1 ‰ (264 ± 0.3) for IOM, +39 ± 16 ‰ (262 ± 4) for UOM, and + 72 ± 9 ‰ (254 ± 2) for NH4+. Although IOM and NH4+ have significantly different δ15N, we cannot exclude that these phases could be compositionally related because IOM is heterogeneous in 15N. Ammonium could have been produced via heating and/or aqueous alteration processes of organic matter in the CI parent body. Alternatively, or additionnally, ammonium could be a tracer of the accretion and/or later deposit of NH3 ice, NH3 hydrates, and/or NH4+ salts on the CI parent body. As shown by previous studies, Ryugu grains sampled by the Hayabusa2 mission (JAXA) have heterogeneous compositions at the millimeter scale, with nitrogen concentrations and δ15N similar or lower than Orgueil, possibly because of different parent body processing. The present study suggests that the lack or loss of 15N-rich NH4+ in some Ryugu grains may explain some of these differences with Orgueil.

¹Hitoshi Miura
Icarus (in Press) Open Access Link to Article [https://doi.org/10.1016/j.icarus.2024.116317]
¹Graduate School of Science, Nagoya City University, Yamanohata 1, Mizuho-cho, Mizuho-ku, Nagoya, 467-8501, Aichi, Japan
Copyright Elsevier

In this study, we propose a novel numerical method to simulate the growth dynamics of an olivine single crystal within an isolated, multicomponent silicate droplet. We aimed to theoretically replicate the solidification textures observed in chondrules. The method leverages the phase-field model, a well-established framework for simulating alloy solidification. This approach enables the calculation of the solidification process within the ternary MgO–FeO–SiO2 system. Furthermore, the model incorporates the anisotropic characteristics of interface free energy and growth kinetics inherent to the crystal structure. Here we investigated an anisotropy model capable of reproducing the experimentally observed dependence of the growth patterns of the olivine single crystal on the degree of supercooling under the constraints of two-dimensional modeling. By independently adjusting the degree of anisotropies of interface free energy and growth kinetics, we successfully achieved the qualitative replication of diverse olivine crystal morphologies, ranging from polyhedral shapes at low supercooling to elongated, needle-like structures at high supercooling. This computationally driven method offers a unique and groundbreaking approach for theoretically reproducing the solidification textures of chondrules.

¹Alexei V. Ivanov
Earth and Planetary Science Letters 647, 119058 Link to Article [https://doi.org/10.1016/j.epsl.2024.119058]
¹Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, 128 Lermontov Street, Irkutsk 664033, Russia
Copyright Elsevier

It is frequently proposed that large bolide impacts and voluminous volcanic eruptions may be responsible for environmental catastrophes. In the conventional approach, the potential causes and consequences are matched using an age-versus-age plot, with preferential ages selected for comparison. This approach inevitably results in a one-to-one correlation, which may be misleading. To address this issue, a novel statistical metric, named concordance, has been proposed which accounts for the possibility of age coincidence resulting from random processes (i.e. bad luck coincidence). The available and updated geochronological datasets of bolide impacts, large igneous provinces, CO2-concentration peaks in the atmosphere, mass extinctions, ocean anoxic events, and climatic optima and thermal highs were subjected to a comparison in terms of their concordance. The most significant discovery is the correlation between the ages of mass extinctions and those of giant bolide impacts (crater diameter >40 km), as well as volcanism of continental large igneous provinces and CO2-concentration peaks in the atmosphere. The severity of mass extinctions appears to be dependent upon the number of simultaneously occurring causes. The most pronounced Late Maastrichtian (∼66 Ma) and Changhsingian (∼252 Ma) mass extinctions were likely caused by a combination of factors, including the simultaneous occurrence of volcanism of continental large igneous provinces, giant bolide impact and CO2-concentration rise in the atmosphere. Conversely, the ages of large igneous provinces, bolide impacts and CO2-concentration peaks are not correlated, indicating that these three causes were not interdependent.