¹J. Gattacceca et al. (>10)
Meteoritics & Planetary Science (in Press)
Open Access Link to Article [DOI: 10.1111/maps.70233]
¹CEREGE, CNRS, Aix-Marseille Univ, IRD, INRAE, Aix-en-Provence, France

Published by arrangement with John Wiley & Sons

A minor fraction of meteorites contains xenoliths, that is, clasts that were formed on a different parent body than that of the host lithology. The occurrence of xenoliths is direct evidence for the exchange of material between asteroids, including exchanges between asteroids from the carbonaceous (CC) and non-carbonaceous (NC) reservoirs. Overall xenolith population statistics may therefore inform us about the dynamical mixing of these two asteroid reservoirs. Xenoliths are also intrinsically interesting because they may sample parent bodies that are not represented in the meteorite collection. In this work, we conducted a critical and exhaustive review of xenoliths described in the literature and performed a new large-scale search for macroscopic lithic xenoliths. We identify 89 xenolith-bearing meteorites in the literature, and report 18 new ones. We expand the diversity of known host/xenolith pairs with occurrence that had not been reported before: a CM clast in a L chondrite, a CO3 clast in a eucrite, a pallasite and H clasts in howardites, and two CO-CM breccias. Based on our observations, we reinterpret a number of previously described xenoliths. In particular, many “CI-like” xenoliths should rather be classified as ungrouped C1 or C2 chondrite xenoliths. At least a third of xenoliths do not belong to the known meteorite groups, suggesting that they represent a flux of meteoroids different from the present-day one that is dominated by the products of recent (~<50 Ma) collisions. Although xenoliths are present in only 0.14% of meteorites, the statistics of the total data set of 107 xenolith-bearing meteorites can be discussed in relation with the asteroid population. Xenoliths are more abundant in the regolith breccias of large asteroids, in agreement with their ability to maintain an old and mature regolith. Chondritic xenoliths represent 95% of xenolith occurrence, in line with a higher number of chondritic asteroids with respect to achondritic ones. Xenoliths from the CC and NC reservoirs are found in host meteorites from both reservoirs, and a majority was implanted at low collisional speed (below about 2 km s⁻¹). The low proportion of CC meteorites with NC xenoliths can be related to the fact that the present-day outer asteroid belt that hosts the majority of CC asteroids is depleted in NC asteroids. The broad agreement between the xenolith population and the present-day architecture of the asteroid belt, as well as the low collisional speed between CC and NC materials suggest that the implantation of most xenoliths occurred after the main scattering event of the asteroids triggered by the formation of Jupiter a few Myr after the formation of the solar system. Conversely, CV, CK, and CO chondrites contain only xenoliths from a meteorite group of their own meteorite clan suggesting that these intra-clan xenoliths were implanted while their parent bodies were still orbiting in a narrow range of heliocentric distance, that is, before the main scattering event of the asteroids triggered by the formation of Jupiter. Eventually, a few xenoliths were incorporated in asteroids that were still accreting. Therefore, xenolith implantation seems to have been a universal and protracted phenomenon, active for most of solar system history.

¹Robert Huber, ²Hans Lauterbach, ³Robert Darga
Meteoritics & Planetary Science (in Press) Open Access Link to Article [DOI: 10.1111/maps.70255]
¹MARUM—Center for Marine Environmental Sciences, Universität Bremen, Bremen, Germany
²Independent Researcher, Traunreut, Germany
³MammutMuseum Siegsdorf, Siegsdorf, Germany

Published by arrangement with John Wiley & Sons

Public fascination with impact craters often drives bold speculations, but rigorousverification is critical. In southeastern Bavaria, numerous depressions have been proposed torepresent impact craters associated with a catastrophic event in Celtic times (between 900 BCand 600 BC)—the so called “Chiemgau Impact.” To date, the evidence presented in supportof the proposed Chiemgau Impact has not been independently validated as diagnostic of aconfirmed impact event, and this interpretation has been repeatedly challenged in thescientific literature. More recently, numerous newly identified, predominantly small-scalestructures have been presented as further evidence supporting this claim. Many, however,lack precise geographic information, complicating independent verification. We localized andcritically examined these structures in the field as well as using publicly availablehigh-resolution LIDAR data, aerial imagery (historic and recent), and development plans.The majority of these images show structures which are demonstrably anthropogenic,including gravel pits, WWII bomb craters, retention basins, and—most notably—golf coursefeatures such as bunkers and ponds. Other depressions correspond to glacial landformscharacteristic of the Inn-Chiemsee foreland. None of the structures examined exhibitcharacteristics that would support a formation by a cosmic impact. The repeatedmisinterpretation of recently constructed golf course elements as impact craters highlights astriking lack of methodological rigor and illustrates how extraordinary claims can arise fromneglecting simple cross-checks with publicly available geospatial and planning data andindicates that the postulated impact in Chiemgau belongs to the realm of myths.

^1,2Subhasmita Swain, ³Enrico Mugnaioli, ³Anna Musolino, ⁴Markus Patzek, ^5,6Beda Hofmann, ^1,2,7Surya Snata Rout
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.70245]
¹School of Earth and Planetary Sciences, National Institute of Science Education and Research (NISER), Jatni, Khurda, India
²Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, India
³Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy
⁴Institut für Planetologie, University of Münster, Münster, Germany
⁵Institute of Geology, University of Bern, Bern, Switzerland
⁶Natural History Museum Bern, Bern, Switzerland
⁷Centre for Interdisciplinary Sciences (CIS), National Institute of Science Education and Research (NISER), Jatni, Khurda, India

Published by arrangement with John Wiley & Sons

Volatile-rich xenolithic clasts in different meteoritic breccias represent primitivesolar system material. Here, we report the mineralogy and organic maturity of C1, C2, andCM-like clasts present within five polymict ureilites, two polymict eucrites, one howardite,and one CR chondrite. Of all the clasts, the C1s are the most abundant, and the majorityhave mineralogy and organic maturity similar to the CI chondrites. Two C1 clasts show theleast altered polyaromatic organic matter, similar to Bells, Essebi, and a CR chondrite.A few C1 clasts have unique mineralogy with abundant Fe-rich olivine surroundingmagnetite grains. Such clasts show a Raman signature of mild to moderate heating effectsrelated to impact-shock processing. The Fe-rich olivine within these clasts formed aroundmagnetite grains from an aqueous fluid at a water/rock ratio of 0.1–0.2, T > 150 °C, andhigh activity of SiO 2 and Fe. Additionally, the Fe-rich olivine could have also formedthrough the reduction of magnetite by H 2 gas and SiO 2 (aq). The CM-like clasts are foundonly in the studied HED meteorites and have mineralogy and organic maturity similar to theCM chondrites. Only one CM-like clast shows unique Raman signatures, either due tothermal effects or the presence of unique organic precursor material. The C2 clasts showsimilarities with other C2 clasts in CH/CB chondrites. None of the studied clasts showsignatures of high degrees of thermal metamorphism like the subtype ≥3.1 chondrites.

^1,2Robert W. Nicklas, ^3,4Aratz Beranoaguirre, ²Dylan M. Seal, ⁵James M. D. Day, ²Ethan F. Baxter, ⁶Anthony B. Love
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.70254]
¹Lunar and Planetary Institute, USRA, Houston, Texas, USA
²Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, Massachusetts, USA
³Institut für Geowissenschaften, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
⁴Frankfurt Isotope and Element Research Center (FIERCE), Goethe-Universität Frankfurt, Frankfurt am Main, Germany
⁵Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
⁶Department of Geological and Environmental Sciences, Appalachian State University, Boone, North Carolina, USA

Published by arrangement with John Wiley & Sons

Brachinites and brachinite-like achondrites record melting processes at moreoxidizing conditions than many other achondrite meteorites, attested by relatively Fe-richsilicate phases. Here, new major-, trace-, and highly siderophile-element (Os, Ir, Ru, Pt, Pd,Re) abundances, as well as Re-Os and Rb-Sr isotope data are reported for the brachinite ElMedano 395 and for the anomalously apatite-rich (~1.26% modal) brachinite-like achondriteNorthwest Africa (NWA) 12,532. Both meteorites have Rb-Sr and Re-Os isotope systematicsthat have been significantly affected by terrestrial alteration, reflecting variable addition of Srand variable loss of Rb and Re. Brachinite-like achondrite NWA 12532 experienced lateaddition of metallic phases and apatite on its parent body, having nearly chondriticabundances of Os, Ir, Ru, Pt, and Pd. The apatite in NWA 12532 gives an age of4491.3 14.1 Ma, overlapping with apatite U-Pb ages for ordinary chondrites, as well asfor other brachinites and brachinite-like achondrites. This age is significantly younger thanavailable Mn-Cr ages for brachinite silicate phases. The young U-Pb ages of brachinites andbrachinite-like achondrites likely reflect significant impact shock resetting events at ~4.43 to4.49 Ga across the solar system, also recorded in ordinary chondrites. These resetting eventsmay be related to a significant dynamical reorganization at that time.

¹Shu-Zhou Wang, ¹Ai-Cheng Zhang, ¹Tian-Ran Du, ¹Jia-Ni Chen, ²Yuan-Yun Wen
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.70256]
¹State Key Laboratory for Critical Earth Material Cycling and Mineral Deposits, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China
²Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China

Published by arrangement with John Wiley & Sons

Yamato-type (CY) carbonaceous chondrites are a group of meteorites that experienced both intense aqueous alteration and subsequent dehydration. They consist of a few CY1 and CY2 samples; however, their nature and genetic relationship remains an issue of debate. Here, we report the detailed petrography and mineralogy of four sections of Dhofar 1988, a newly proposed CY chondrite. We find that Dhofar 1988 is a dimict breccia, containing a CY2-like host region (~73 area%) and numerous CY1-like dark clasts (~27 area%). Using Ti-minerals as a clue, we identified 14 calcium-aluminum-rich inclusions (CAIs) (including an Al-rich chondrule containing CAI material, with most of the CAIs present in the host region, ~1 area%) and only one CAI in dark clasts (~0.04 area%). These CAIs contain a series of Ti-minerals, including primary perovskite, Ti-rich fassaite, Ti-rich hibonite, and probably ilmenite–rutile assemblage, and secondary ilmenite, anatase, rutile, zirconolite (ideal formula CaZrTi₂O₇), and perovskite. Formation of the secondary Ti-minerals involves: (1) replacement of Ti-rich fassaite by melilite-like phase, perovskite, and minor spinel; (2) subsolidus breakdown of potential armalcolite to ilmenite and rutile and minor spinel and zirconolite; (3) alteration of perovskite to ilmenite; (4) alteration of perovskite to anatase; (5) alteration of fassaite to phyllosilicate and ilmenite; and (6) transition from ilmenite to perovskite. They probably formed during pre-alteration metamorphism (1 and 2), intense aqueous alteration (3–5), and postalteration metamorphism (6), respectively, and reflect the evolution of temperature and water/rock ratio. The similarity between the two components in Dhofar 1988 and the CY1 and CY2 samples indicates that the material from CY1 and CY2 samples was once mixed with each other through collision-induced mixing or during initial planetesimal accretion.

¹Hannah H. Kaplan, ¹Amy A. Simon, ²Victoria E. Hamilton, ³Joshua P. Emery, ¹Dennis Reuter, ¹Andy J. López-Oquendo
Meteoritics & Planetary Science (in Press)
Open Access Link to Article [DOI: 10.1111/maps.70239]
¹Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
²Solar System Science & Exploration Division, Southwest Research Institute, Boulder, Colorado, USA
³Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, Arizona, USA

Published by arrangement with John Wiley & Sons

This study investigates the spatial distribution and spectral characteristics of the broad hydration feature near 3 μm across the surface of asteroid (101955) Bennu using OVIRS (OSIRIS-REx Visible and InfraRed Spectrometer) data. We analyzed multiple global OVIRS data sets obtained at different times throughout the Bennu day, revealing variations in band depth with wavelength, as well as wavelength-dependent correlations with temperature and other surface properties. Our analysis distinguishes between the behavior of the 2.74-μm and 3.0-μm features, which contribute to a broad 3-μm region absorption, suggesting they may have different origins or respond differently to surface conditions. The 2.74-μm band depth shows strong negative correlation with temperature and positive correlation with albedo and hydroxyl, whereas the 3.0-μm band depth exhibits primarily weak relationships with other spectral and surface parameters, such as temperature, albedo, and UV/visible spectral slope, indicating that these features probe different aspects of the surface materials. These findings demonstrate that space weathering likely plays a strong role within the hydration band. Specifically, temperature and time-of-day dependencies observed at 2.74-μm point to an active hydroxyl cycle on Bennu’s surface driven by solar wind hydrogen implantation, hydroxylation, and subsequent thermal desorption. Conversely, the distinct behavior of the 3.0-μm band suggests it may serve as an indicator of surface composition, including the phosphate minerals recently found in the returned sample; however, the lack of correlation with other expected diagnostic spectral features, such as a bluer UV/visible slope, currently leaves this relationship inconclusive.

¹Giorgio S. Senesi, ²Albert Jambon, ¹Olga De Pascale, ^3,4Lahcen Ouknine, ^3,4Hassan Nachit, ^4,5Fouad Khiri, ^3,4Abderrahmane Ibhi
Meteoritics & Planetary Science (in Press)
Open Access Link to Article [DOI: 10.1111/maps.70242]
¹CNR—Istituto per la Scienza e Tecnologia dei Plasmi (ISTP)—sede di Bari, Bari, Italy
²Université Côte d’Azur, Sorbonne Université, CNRS, OCA, IRD, Geoazur, Valbonne, France
³Earth Sciences Department, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco
⁴University Meteorites Museum, Ibn Zohr University, Agadir, Morocco
⁵Faculty of Sciences, Earth Sciences Department, Laboratory of Geosciences, Environment and Geomatics (GEG), Ibn Zohr University, Agadir, Morocco

Published by arrangement with John Wiley & Sons

Despite meteorites having been recognized as the source of iron in some ancientiron artifacts, few archeological irons have been analyzed so far, as invasive methods areprecluded. In this work, four iron knives and one axe collected near Guelmime and Imilchil(Morocco) were investigated by advanced analytical techniques, including handheldlaser-induced breakdown spectroscopy (hLIBS), still not yet widely used, and portableX-ray fluorescence (pXRF). The analyzed objects are undated iron findings recoveredwithout an archeological context and represent test cases for assessing the analyticalcapabilities of hLIBS on corroded iron objects of possible meteoritic origin. Major andtrace element analyses, internal stratigraphy by depth profiling, and microscalecompositional mapping have been performed, which allowed assessment of the samplecomposition, heterogeneity, and corrosion. One of the five specimens studied appeared to bemade of meteoritic iron. The relative uncorroded state of this specimen, when compared toBronze Age irons, enabled investigation of the effect of forging on the composition,especially the mobility of Ni. In particular, the reliability of hLIBS-acquired analytical datafor the major elements Fe and Ni and the trace elements Ge and Au was shown. As well, apossible source relationship of sample #5 with NWA 859 (Taza)/Oglat Sidi Ali meteoritewas discussed and proposed, based on the chemical variations ascribed to the interplay ofprimordial heterogeneity and the introduction of carbon upon forging and corrosion.Furthermore, the analytical limitations of the hLIBS technique were suggested not to beinstrumental, but due to the heterogeneity of natural specimens, confirming that hLIBSrepresents a robust analytical tool for future field archeology and archeometric studies.

¹M. Kimura, ¹N. Imae, ²M. Komatsu, ¹A. Yamaguchi
Meteoritics & Planetary Science (in Press)
Open Access Link to Article [DOI: 10.1111/maps.70248]
¹National Institute of Polar Research, Tokyo, Japan
²Division of Liberal Arts and Sciences, Saitama Prefectural University, Saitama, Japan

Published by arrangement with John Wiley & Sons

Carbonaceous chondrites commonly contain amoeboid olivine aggregates (AOAs).Here, we investigated an AOA in the CR chondrite Y-793261. This AOA contains anunstable assemblage of forsterite and quartz. We found a rare occurrence of enstatite andquantitatively discuss its formation process. This enstatite occurs specifically betweenforsterite and quartz, indicating a solid-state reaction between them. By applying theexperimental results of Imae et al. (Proc. Japan Aca. 75: 229–234), we determined that thisAOA formed under high-temperature conditions (≳1169 K) over a period of approximately1–5 years. The reservoir where the AOA formed was enriched in 16 O. Subsequently, it cooledrapidly and was transported to the reservoir where the parent body accreted, incorporatingchondrules and matrix. The thermal history and physicochemical conditions of this AOA areapplicable to other AOAs.

^1,2,3A. Valantinas, ¹J. F. Mustard, ⁴A. Tullo, ⁵M. S. Bramble, ¹J. W. Head
Earth and Planetary Science Letters, 696, 120390
Open Access Link to Article [DOI: 10.1016/j.epsl.2026.120390]
¹Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, USA
²Department of Earth and Planetary Sciences, ETH Zurich, Zurich, Switzerland
³Department of Earth Sciences, University of Cambridge, Cambridge, UK
⁴INAF, Osservatorio Astronomico di Padova, Padova, Italy
⁵Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

Copyright Elsevier

The origin of the >100,000 km² regional olivine unit in the Nili Fossae-Jezero region has been variously attributed by orbital studies to airfall, effusive lavas, impact melt, or intrusive emplacement. In situ characterization of olivine-bearing igneous rocks in Jezero crater by the Mars 2020 Perseverance rover has revealed olivine cumulate textures indicative of effusive or intrusive magmatism, but conduits in the shallow-crustal feeder system that transported olivine-saturated magma have not been identified. Here we combine sub-meter pansharpened imagery from the Colour and Stereo Surface Imaging System (CaSSIS) and the High Resolution Imaging Science Experiment (HiRISE) with near-infrared spectral analysis from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to characterize a population of olivine-rich ridges and elongated features that crosscut the Fe/Mg-smectite basement at the “Horseshoe” site in Nili Fossae, ∼200 km north of Jezero. The features display a continuum of morphologies, from planar dike-like ridges through sinuous and braided lineaments that locally crosscut topography. Analysis of the 1 µm olivine near-infrared absorption places the features along the same compositional trend as the regional olivine–carbonate assemblage, and CRISM spectra resolve weak 1.9 and 2.32 µm absorptions diagnostic of hydrated/hydroxylated phases, indicating partial alteration of the intrusive olivine. We interpret these features as exhumed magmatic intrusions in a hydrated smectite basement, possibly exploiting pre-existing fault networks, and propose that they form part of a broader Jezero-Nili Fossae magmatic province. Magma-clay contact zones of this kind may provide a unique class of habitable environments in the shallow Noachian crust of Mars.

^1,2Xiaojia Zeng, ^1,2Xiongyao Li
Geochimica et Cosmochimica Acta (in Press) Link to Article [DOI: 10.1016/j.gca.2026.10.025]
¹State Key Laboratory of Critical Mineral Research and Exploration, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China
²Center for Lunar and Planetary Sciences, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, China

Copyright Elsevier

Electrostatic discharge in Martian dust storms may significantly drive the chemical alteration and cycling of surface materials. Troilite is expected on Mars from magmatic and meteoritic sources but remains undetected by rovers, raising the question of possible electrostatic discharge-driven alteration. However, this hypothesis lacks direct experimental support. In this study, we experimentally simulate electrical discharge under Martian conditions by exposing troilite to such discharge in a CO₂ atmosphere at low pressure. We found that electrical discharge rapidly oxidizes troilite to magnetite (Fe₃O₄), forming a ∼ 100 nm thick, polycrystalline, defect-rich alteration layer on the troilite surface. This oxidation is driven by reactive oxygen species attack Fe-S bonds, displace sulfur, and convert the residual iron framework into magnetite. Such an electrical discharge-driven pathway offers a new water-free mechanism for magnetite formation on Mars, specifically active during the hyper-arid Amazonian epoch. This work also provides an additional explanation for the missing troilite in Martian soils and the widespread occurrence of magnetite in Martian dust. More broadly, this study expands our understanding of Martian surface evolution beyond water-dominated scenarios and highlights oxidative role of ongoing dust activities on present-day Mars.