^1,2Ke Zhu, ³Martijn Klaver, ^4,5,6Wei-Biao Hsu, ⁷Harry Becker, ⁸Lu Chen, ⁹Qi Chen
Geochimica et Cosmochimica Acta (in Press) Open Access Link to Article [https://doi.org/10.1016/j.gca.2025.10.009]
¹Bristol Isotope Group, School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol BS8 1RJ, United Kingdom
²State Key Laboratory of Geological Processes and Mineral Resources, Hubei Key Laboratory of Planetary Geology and Deep-Space Exploration, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
³Institut für Mineralogie, Westfälische Wilhelms-Universität Münster, Corrensstraße 24, 48149 Münster, Germany
⁴CAS Center for Excellence in Comparative Planetology, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210023, China
⁵State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau
⁶School of Earth Sciences and Engineering, International Center for Isotope Effects Research, Nanjing University, Nanjing 210023, China
⁷Freie Universität Berlin, Institut für Geologische Wissenschaften, Malteserstr. 74-100, 12249 Berlin, Germany
⁸Wuhan SampleSolution Analytical Technology Co., Ltd, Wuhan, China
⁹Department of Earth Science & Environmental Change, University of Illinois at Urbana Champaign, Urbana, IL, United States
Copyright Elsevier

To understand accretion and differentiation of Mars, we report high-precision mass-dependent Ni (siderophile and chalcophile) isotope data of 37 bulk Martian meteorites. Large δ60/58Ni variations observed among these Martian meteorites are attributed primarily to magmatism and Ni diffusion in zoned olivine and sulfide. Shergottites show systematically higher Mg# and lower δ60/58Ni values relative to nakhlites, which can be caused by olivine crystallization, consistent with the Ni isotope fractionation factor between olivine and melt. Two Ni-rich chassignites (Martian dunites) provide the best current estimate of the upper limit of δ60/58Ni of bulk silicate Mars (BSM): 0.110 ± 0.031 ‰, since olivine crystallization causes Ni isotope fractionation. Subtracting a presumably chondritic contribution by late accretion, the proto-BSM should possess a δ60/58Ni of ≤ 0.074 ‰ that is lower than the average of chondrites (∼0.24 ‰). This sub-chondritic value of Martian mantle suggests the sulfur-rich core formation has not caused Ni isotope fractionation, because the sulfide and Martian sulfur-rich core is believed to enrich in light Ni isotopes. Instead, Ni isotope differences between Earth, Mars, Vesta, and the ureilites can be inherited from non-bulk chondritic precursor materials.

^1,2S. Iannini Lelarge,^2,3M. Masotta,^2,3L. Folco,⁴T. Ubide,^2,5M.D. Suttle,^6,7L. Pittarello
Geochemistry (Chemie der Erde) 88, 126293 Link to Article [https://doi.org/10.1016/j.chemer.2025.126293]
¹Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Via Moruzzi 1, 56124 Pisa, Italy
²Dipartimento di Scienze della Terra, Università di Pisa, Via Santa Maria 53, 56126 Pisa, Italy
³CISUP, Centro per l’Integrazione della Strumentazione Università di Pisa, Lungarno Pacinotti 43, Pisa 56126, Italy
⁴School of Earth and Environmental Sciences, The University of Queensland, Brisbane 4102, QLD, Australia
⁵School of Physical Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
⁶Naturhistorisches Museum, Mineralogisch-Petrographische Abteilung, Burgring 7, 1010 Vienna, Austria
⁷Department of Lithospheric Research, University of Vienna, Josef-Holaubek-Platz 2,1090 Vienna, Austria
Copyright Elsevier

We conducted high-pressure (1 GPa) melting experiments (1100–1400 °C) on the equilibrated ordinary chondrite DAV 01001 (L6) to investigate partial melting scenarios of planetary embryo in the early solar system. At 1100 °C, no melting of the silicate phase is observed, and the initial chondritic texture is preserved, but the metallic-sulphidic phases formed two immiscible Fe–Ni and S-rich liquids. Melting of silicate minerals began at 1200 °C, progressing from plagioclase to high-Ca and low-Ca pyroxene and olivine. As melting advanced, the formation of new olivine and low-Ca pyroxene resulted in the production of trachy-andesitic melt at 1200 °C, basaltic trachy-andesitic melt at 1300 °C, and andesitic melt at 1400 °C. These silicate melts have chemical similarities with some anomalous achondrites (e.g., GRA 60128/9). At the same time, minerals of new formation resemble those of primitive achondrites (e.g., brachinites, ureilites, IAB silicate inclusions, acapulcoites and lodranites). The rapid mineral-liquid re-equilibration suggests that basaltic liquids can form only above 1400 °C and that relatively high degrees of melting (>20 %) and crystallisation are necessary to explain the observed diversity of achondritic lithologies. These findings suggest that partial melting and recrystallization processes within planetary embryos could have played a critical role in the early solar system, contributing to the early differentiation of planetary bodies and the diversity of achondritic lithologies, including (but not limited to) alkali-rich achondrites.

^1,2Seann J. McKibbin,^3,4Lutz Hecht,^5,6Matthew S. Huber,²Christina Makarona,^7,8Stepan M. Chernonozhkin,²Philippe Claeys,²Steven Goderis
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70064]
¹Geowissenschaftliches Zentrum, Abteilung für Geochemie und Isotopengeologie, Georg-August-Universität Göttingen, Göttingen, Germany
²Archaeology, Environmental Changes, and Geo-Chemistry, Vrije Universiteit Brussel, Brussels, Belgium
³Museum für Naturkunde Berlin, Leibniz Institut für Evolutions und Biodiversitätsfoschung, Berlin, Germany
⁴Institut für Geologische Wissenschaften, Freie Universität Berlin, Berlin, Germany
⁵Planetary Science Institute, Tucson, Arizona, USA
⁶University of KwaZulu-Natal, Durban, South Africa
⁷Department of Chemistry, Atomic & Mass Spectrometry A&MS Research Unit, Ghent University, Ghent, Belgium
⁸Montanuniversität Leoben, General and Analytical Chemistry, Leoben, Austria
Published by arrangement with John Wiley & Sons

Main group pallasite meteorites (PMG) are samples of an early, highly differentiated magmatic planetesimal dominated by olivine and metal-sulfide-phosphide assemblages with accessory chromite among other phases. This mineralogy reflects mantle- and core-related reservoirs, but the relative contributions of each and the overall petrogenesis are obscured by high degrees of protolith melting. Here, we present new data on the chemistry of chromite in these meteorites and review previous datasets. The purely lithophile elements Mg and Al partition into chromite via (Mg,Fe)(Al,Cr)2O4 and mainly reflect interactions with olivine and basaltic melt, respectively. Chromite cores are virtually always more aluminous than rims, and while MgO contents were likely reset during slow cooling, their Al2O3 contents are more robust and were largely set during the period of silicate magmatism. Main group pallasite chromites display bimodality in Al2O3 contents, with peak concentrations at ~7.7 wt% and below 6 wt%, which is unlike any other achondrite chromite population. Some chromites have very low Al2O3 contents (~0.01 wt%) due to formation in the absence of silicate melt, that is, via exsolution of Cr from cooling liquid metal. High-, low-, and very low-Al2O3 chromites in these meteorites broadly reflect relict, prograde, and retrograde periods of planetesimal heating followed by cooling. The Al2O3 contents of the chromites in many other achondrites and equilibrated chondrites are similar to the higher values in pallasites, with most greater than 3 wt%. This suggests that meteoritic chromite is a significant sink for 26Al during its life as a heat source for planetesimal differentiation. To first order, it may be responsible for ~25%–50% (i.e., about one third) of heating in partially depleted mantles.

¹L. Miché Aaron-Hennig, ²Kim Seelos
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2025.116835]
¹Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
²Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723, USA
Copyright Elsevier

Understanding the distribution and provenance of hydrated minerals within Noachian terrains is essential to deciphering Mars’ crustal formation and alteration history. The phyllosilicate and carbonate minerals typically found within Noachian geologic units, for instance, have been attributed to a warmer, wetter climate that preceded a transition to the sulfate-dominated, colder, drier, and more acidic conditions in the Hesperian and Amazonian. However, these broad associations may not hold true locally. In Tyrrhena Terra, the heart of the Noachian-aged cratered highlands, three isolated craters host an unusual occurrence of hydrated sulfates alongside a variety of other alteration minerals more typically associated with the Noachian era. This paper investigates the presence of these outcrops in order to understand their origin, relationship to these co-located minerals, and implications for aqueous history and crustal evolution of Mars. Using Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) data along with other contextual remote sensing data, we present a mineralogical mapping and spectral analysis of primary and secondary minerals at each location where sulfates are observed. Based on our characterization, we have constrained the formation of the sulfates to be associated with epithermal alteration or sulfide oxidation rather than impact or mechanically induced alteration. This suggests a complex sequence of aqueous alteration, potentially involving one or more steps, which we intend to explore further in future studies. The discovery of these sulfate minerals within predominantly phyllosilicate and carbonate territories challenges the conventional timeline of Mars’ climate evolution, hinting that transitions between climatic epochs may have overlapped or been more regionally varied than previously thought.

^1,2Varsha M. Nair, ¹Amit Basu Sarbadhikari, ³G.N.S. Sree Bhuvan, ⁴T. Vijaya Kumar, ^5,6Nilanjana Sorcar, ⁶Sneha Mukherjee, ⁴E.V.S.S.K. Babu, ¹Jyotiranjan S. Ray
Geochimica et Cosmochimica Acta (in Press) Link to Article [https://doi.org/10.1016/j.gca.2025.09.043]
¹Physical Research Laboratory, Ahmedabad 380009, India
²Indian Institute of Technology Gandhinagar, Gujarat 382355, India
³Department of Earth Sciences, Pondicherry University, Puducherry 605014, India
⁴CSIR-National Geophysical Research Institute, Hyderabad 500007 India
⁵National Centre for Earth Science Studies, Akkulam, Thiruvananthapuram 695011, India
⁶Korea Polar Research Institute, Incheon 21990, the Republic of Korea
Copyright Elsevier

Martian meteorite Northwest Africa (NWA) 1950 is a poikilitic shergottite whose whole-rock chemical and isotopic composition indicates its origin from an intermediate mantle source. In this study, we report the results of a detailed petrographic, in-situ trace element, and whole-rock Sr-Nd isotopic investigation carried out on NWA 1950 to understand the cause of the apparent absence of the depleted poikilitic shergottites among the Martian meteorites. The sample exhibits distinct poikilitic and non-poikilitic textural domains. The large pyroxene oikocrysts (up to ∼2 mm) enclose early-formed olivine and chromite inclusions (chadacrysts) in the poikilitic domain. The non-poikilitic domain comprises olivine, pyroxene, maskelynite, merrillite, and other late-stage minerals. Pyroxenes exhibit a highly LREE-depleted pattern, and maskelynite shows no evidence of LREE enrichment. Merrillite is characterized by low REE abundance and a slight negative Eu anomaly, resembling those of depleted olivine-phyric shergottites like Tissint. Olivine grains contain abundant melt inclusions in the poikilitic and non-poikilitic domains. Oxygen fugacity values in the poikilitic and non-poikilitic domains are QFM-2.8 and QFM-2.5, respectively. The measured 87Sr/86Sr and 143Nd/144Nd ratios for NWA 1950 whole-rock are 0.710432 ± 0.000027 and 0.513201 ± 0.000011, respectively. The REE pattern of melt inclusions is depleted, resembling the depleted shergottites, while the whole-rock REE and Sr-Nd isotopic compositions are of intermediate class. This characteristic of the NWA 1950 melt inclusions enables us to establish a genetic linkage between the intermediate and depleted shergottites and to find out the missing link for the depleted poikilitic shergottites.
The parent magma of NWA 1950 is more magnesian and less aluminous than that of the enriched poikilitic shergottites in the same manner that depleted olivine-phyric shergottites have more Mg and less Al than their enriched counterparts. Additionally, the modal proportion of pyroxene to plagioclase and REE abundance in merrillite of NWA 1950 closely matches the depleted olivine-phyric shergottites. The observed enrichment in trace elements and the Sr-Nd isotopic compositions cannot be explained by a depleted mantle source, as inferred from the REE patterns of the constituent minerals in NWA 1950. We propose such enrichment to have originated due to the heterogeneity in the shergottite mantle, aided by the entrapped melt pockets within the upper mantle. A mixture of 0.3–1.0 % trapped liquid in the Martian upper mantle with the parent melt can produce the high REE abundance and Sr-Nd isotopic composition of NWA 1950. Longer residence time in the magma chamber and slower cooling rate of the poikilitic shergottites than the extrusive shergottites could have aided the enrichment in the source region. Additionally, this study suggests that care must be taken in classifying the chemical and isotopic characteristics of the poikilitic shergottites in future studies.

¹Molly C. McCanta,^2,3M. Darby Dyar,^4,5Stephen R. Sutton,⁶Sarah E. Roberts,^7,8Cai R. Ytsma
American Mineralogist 110, 1597-1613 Link to Article [https://doi.org/10.2138/am-2024-9602]
¹Department of Earth, Environment, and Planetary Sciences, University of Tennessee, 1621 Cumberland Avenue, Knoxville, Tennessee 37996, U.S.A.
²Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, Arizona 85719, U.S.A.
³Department of Astronomy, Mount Holyoke College, 50 College Street, South Hadley, Massachusetts 01075, U.S.A.
⁴Center for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637, U.S.A.
⁵Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois 60637, U.S.A.
⁶Corning Glass, Corning, New York 14830, U.S.A.
⁷Cai Consulting, Glasgow, Scotland, U.K.
⁸Institute of Health Informatics, University College London, Gower Street, London WC1E 6BT, U.K.
Copyright: The Mineralogical Society of America

Iron redox works well for constraining oxygen fugacity (⁠⁠) in terrestrial igneous materials due to the relatively high  of the Earth’s atmosphere, crust, and upper mantle ⁠, where there are large changes in Fe²⁺/Fe³⁺ with relatively small changes in ⁠. At  values <QFM, Fe redox becomes less sensitive, and analytical uncertainties may make it difficult to determine  differences between samples. The valence change between Cr²⁺ and Cr³⁺ occurs at lower  values than for iron, potentially making it a more sensitive oxybarometer for materials equilibrated under reducing conditions. The current approach to measuring  from X-ray absorption (XAS) measurements derives Cr valence first from the 1s → 4s transition and then uses that redox couple to estimate  as a function of temperature and composition. Here, that method is compared to an alternate approach of predicting  directly from the spectra of experimentally homogenized glasses of geological relevance without an intermediate step of attempting to discern Cr²⁺/Cr³⁺. In this study, partial least-squares (PLS) multivariate (MVA) regression models were trained on the whole XAS energy spectral range, and accuracy was quantified using root mean square error (RMSE). MVA results showed significantly higher accuracy (RMSE-C of ±0.75 log units) for predicting  ΔIW relative to known experimental conditions relative to the two-step method, which yielded RMSE-C of ±2.75 to ±7.65 log units for our data set vs. those of Berry and O’Neill (2004) and Berry et al. (2006), respectively. The MVA results calibrate a new Cr oxybarometer for use in low- glasses with a cross-validated (RMSE-CV) accuracy of ±0.84 log units  relative to a standard oxygen buffer. Finally, the new Cr oxybarometer was applied to lunar glasses, both volcanic and impact metamorphosed, to assess the range in oxidation conditions the materials experienced during formation. Lunar volcanic glasses cluster ∼IW±1, close to that of previous studies while agglutinates and lunar impact melts record a wide range of  values using Cr oxybarometry.

¹Dwijesh Ray,¹Aditya Das,¹Subham Sarkar,²Satadru Bhattacharya,³Chandrani Nayak
American Mineralogist 110, 1516-1526 Link to Article [https://doi.org/10.2138/am-2024-9360]
¹Physical Research Laboratory, Ahmedabad 380 009, India
²Space Applications Centre (ISRO), Ahmedabad 380 015, India
³Atomic & Molecular Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
Copyright: The Mineralogical Society of America

We report mineralogy, chemical composition, visible near-infrared (VNIR) spectroscopy, and X-ray near-edge spectroscopy of phyllosilicate-sulfate mineral assemblages, including natrojarosite, from the Matanomadh Formation (Palaeocene) of the Kutch region in Gujarat, India. The unit-cell parameters of sulfate minerals and VNIR spectral properties are consistent with natrojarosite and other minerals. The mineralogy and unit-cell parameters indicate supergene or hydrothermal alteration conditions within the Kutch region. The Fe oxidation record (Fe3+/total Fe ∼0.83) is quantified using Fe K-edge XANES. Additionally, the Fe-S bond length for natrojarosite is determined to be 3.158 Å, and the experimental result fits well with the modeled iron sulfate data curve. The occurrences of natrojarosite and associated natroalunite and kaolinite in the post-Deccan volcanic province are consistent with an oxidizing environment and periodic shift of humid to arid environments that appear to be similar to the early geologic history of Mars. The oxidative alteration of pyrite further enhances the formation of natrojarosite. Our results, in concert with earlier studies, highlight the formation process of natrojarosite and provide insights into detailed mineralogy at the Kutch region and the magnitude of the redox state. The natrojarosite and the associated minerals (including anhydrite and other sulfates) argue for acidic and water-limited conditions analogous to the Noachian-Hesperian epoch of Mars, with implications for past weathering processes.

¹Addi Bischoff et al. (>10)
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70060]
¹Institut für Planetologie, University of Münster, Münster, Germany
Published by arrangement with John Wiley & Sons

On October 24, 2024, an impressive fireball was visible over Austria. After the possible strewn field was calculated, the first sample of the Haag meteorite, with a mass of 8.76 g, was discovered on November 2, 2024, 8 days after the fireball event. Four more samples were found afterward putting the total sample mass at about 151 g. Short-lived radionuclides were measured shortly after recovery on a small sample, which was also used for almost all analyses presented here. Results confirm that the Haag meteorite derived from the bolide fireball event. Haag is a severely fragmented ordinary chondrite breccia and consists of typical equilibrated and recrystallized lithologies (LL4-6) as well as impact-related lithic clasts, such as dark, fine-grained impact breccias. Most fragments are highly recrystallized (type 6), but some show a well-preserved chondritic texture, which is of petrologic type 4 since the olivines are equilibrated. The olivines in the bulk rock have Fa contents of 29.5 ± 0.5 mol%, whereas the low-Ca pyroxenes have compositions of Fs23.9±1.4Wo1.6±0.7 with slightly variable Fs contents up to 28 mol%. However, the occurrence of type 3 fragments in other parts of the rock cannot completely be ruled out. Many clasts are moderately shocked (S4; C-S4). Using the fragment with the lowest degree of shock to determine the bulk rock’s shock degree, Haag has an overall shock degree of S2 (C-S2). The LL chondrite classification is also supported by O isotope data, the results of bulk chemical analysis, and the physical properties of density and magnetic susceptibility. The nucleosynthetic Ti and Cr isotope data confirm that Haag is an ordinary chondrite, related to the noncarbonaceous (NC) meteorites. Haag does not contain detectable amounts of solar wind-implanted noble gases, and we rule out any substantial exposure at the direct surface of the parent body. Based on noble gases, Haag has an exposure age of 21–24 Ma and a pre-atmospheric meteoroid radius of 20–85 cm with a sample depth between 4 and 5 cm below the meteoroid surface, consistent with constraints from cosmogenic radionuclides. The soluble organic compositions of Haag are consistent with the profiles of the Stubenberg (LL6) breccia and show characteristics consistent with the complex shock, brecciation, and lithification history of the breccia. Haag and Stubenberg fell near each other (110 km away) within just 8 years. Since only 8.5% (about 110) of meteorite falls worldwide are LL chondrites, it is remarkable that two LL chondrites fell near each other in such a short time.

¹I. Baziotis,^2,3L. Ferrière,⁴C. Ma,⁴J. Hu,⁵D. Palles,⁴P. D. Asimow
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70054]
¹Department of Natural Resources Management and Agricultural Engineering, Agricultural University of Athens, Athens, Greece
²Natural History Museum Vienna, Vienna, Austria
³Natural History Museum Abu Dhabi, Abu Dhabi, United Arab Emirates
⁴Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA
⁵Theoretical & Physical Chemistry Institute, National Hellenic Research Foundation, Athens, Greece
Published by arrangement with John Wiley & Sons

We report new results from a study of shock-related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high-pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite. Based on the calibration of phase stability fields and majorite chemical variations from static experiments, we estimate peak shock conditions of 18–23 GPa and 1800–2100°C. However, both meteorites also contain minerals thought to record lower pressures, 14–18 GPa for wadsleyite, and possibly ~11.5 GPa for albitic jadeite. These are interpreted to have formed by cooling during partial release from the peak shock state. Although the presence of discrete shock melt veins demands spatial heterogeneity in the temperature field, we interpret the record of HP mineralogy in terms of temporal rather than spatial variation in pressure–temperature conditions during the shock and release event. Specifically, we infer that the cooling of shock melt veins to their liquidus occurred near peak pressure, whereas decompression began before the melt veins reached their solidus. NWA 4672 and NWA 12841 also display dense networks of shock melt veins, metal–sulfide segregations, and dark shock zones, implying a high density of pre-existing weak zones and, thus, a high likelihood of fragmentation during atmospheric entry. A comparison with the Suizhou L6 chondrite, in which a total of 26 HP phases have been identified, suggests that differences in the identification and number of observed HP polymorphs mostly reflect differences in the completeness and spatial scale of analytical studies rather than a true difference in the intensity of shock processing. It remains quite likely that many shocked L chondrites host more HP phases than have been recognized so far. These new results indicate a need for further high-resolution studies of L chondrites to distinguish between observational bias and true variations in the range of shock states they experienced.

¹Léna Jossé,¹Zélia Dionnet,¹Alice Aléon-Toppani,¹Rosario Brunetto,²Andrew King,³Emmanuel Gardés,⁴Eva Heripré,^1,5Damien Loizeau,¹Sasha Cryan,⁶Kentaro Hatakeda
Meteoritics & Planetary Science (in Press) Open Access Link to Article [https://doi.org/10.1111/maps.70056]
¹Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale (IAS), Orsay, France
²SOLEIL Synchrotron, Gif-sur-Yvette, France
³Laboratoire Magmas et Volcans (LMV), Université Clermont Auvergne, CNRS, IRD, Clermont-Ferrand, France
⁴Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Arts et Métiers Sciences et Technologies, CNRS, CNAM, Paris, France
⁵Qualisat, Bièvres, France
⁶Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Japan
Published by arrangement with John Wiley & Sons

Extraterrestrial breccia samples are formed through impact-related processes that combine the fragments of distinct lithologies. As such, they are valuable indicators of the complex formation and evolution history of planetesimals in our solar system. Samples from asteroid (162173) Ryugu, returned to the Earth by the Hayabusa2 mission in December 2020, were characterized as breccias. The boundaries of mineralogical assemblages are typically drawn manually based on interpreted results from specific techniques, mostly performed on artificially produced 2D surfaces. This process inherently introduces subjectivity. Here, we present a semi-automated analytical method using synchrotron radiation micro X-ray computed tomography (SR-μXCT) data, called the Local Histogram method. It enables an unsupervised detection and 3D visualization of a few tens to hundreds of micrometer-sized lithologies showing sub-micrometer heterogeneities. We developed the method on a millimeter-sized Ryugu sample (A0159) in combination with a more traditional global grayscale threshold segmentation. In A0159, we report five distinct lithologies. They were confirmed and further characterized by an additional scanning electron microscopy (SEM) analysis on Xenon plasma-focused ion beam (Xe-pFIB) produced sections. Some lithologies show specific relationships with large fractures, while one is particularly enriched in sub-micrometer sulfides. A0159 is rich in carbonates and hosts the largest millimeter-scale dolomite vein seen on Ryugu.