Meteoritics & Planetary Science最新文献

{"title":"Apatite in Bennu samples indicates multiple stages of aqueous alteration","authors":"Laura B. Seifert,&nbsp;T. M. Erickson,&nbsp;L. P. Keller,&nbsp;J. J. Barnes,&nbsp;K. Thomas-Keprta,&nbsp;L. Le,&nbsp;J. Gorce,&nbsp;Z. Rahman,&nbsp;T. J. Zega,&nbsp;H. C. Connolly Jr,&nbsp;D. S. Lauretta","doi":"10.1111/maps.70093","DOIUrl":"https://doi.org/10.1111/maps.70093","url":null,"abstract":"<p>Calcium phosphates are ubiquitous in planetary materials, including samples returned from asteroid Bennu by the OSIRIS-REx mission. We characterized apatite [Ca₅(PO₄)₃(F,Cl,OH)] grains in Bennu samples by scanning electron microscopy, electron microprobe analysis, and transmission electron microscopy to investigate their compositions, mineral associations, and microstructures. We find that Bennu apatite is halogen-poor, consistent with a composition of hydroxyapatite, and can be separated into two main structural types: single crystals, which often exhibit etched crystal faces, and anhedral polycrystalline assemblages. Both types exhibit zoning in cathodoluminescence imaging that results from incorporation of trace Mn²⁺ and rare earth elements into the apatite structure during crystal growth. Transmission electron microscopy of a single phosphate crystal and a polycrystalline assemblage reveals close association between apatite and phyllosilicates in the surrounding matrix. Phyllosilicates are either oriented parallel to intact apatite crystal facets or radiating from altered crystal faces. We interpret that single crystals with or without etched crystal faces are among the least aqueously altered of the observed apatites, whereas polycrystalline assemblages exhibiting a porous texture, consistent with successive dissolution–reprecipitation reactions, represent assemblages that experienced more extensive aqueous alteration. These microstructural data suggest that several stages of aqueous alteration likely occurred on Bennu's parent body, leading to the mineral assemblages observed here.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"504-521"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147565729","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Al-Khadhaf: The first camera-observed (H5–6) meteorite fall from Oman","authors":"Anna Zappatini,&nbsp;Edwin Gnos,&nbsp;Beda A. Hofmann,&nbsp;Urs Eggenberger,&nbsp;Pascal M. Kruttasch,&nbsp;Frank Gfeller,&nbsp;Mohammad Tauseef,&nbsp;Ingo Leya,&nbsp;Hadrien A. R. Devillepoix,&nbsp;Eleanor K. Sansom,&nbsp;Martin Cupák,&nbsp;Sophie E. Deam,&nbsp;Thomas W. C. Stevenson,&nbsp;Peter Jenniskens,&nbsp;Sebastian Lindemann,&nbsp;Beat Booz,&nbsp;Muati. S. Al-Muati,&nbsp;Abdulmunaim A. Al-Zakwani,&nbsp;Hussain A. Al-Ghafri","doi":"10.1111/maps.70110","DOIUrl":"https://doi.org/10.1111/maps.70110","url":null,"abstract":"<p>A fireball camera system installed in 2022 by the Oman Meteorite Monitoring Project (OMMP) as part of the Global Fireball Observatory (GFO) recorded a 3.2 s fireball on March 8, 2022 at 8:15 p.m. UTC. A meteoroid of 4 ± 2 kg entered the atmosphere at 14.0 km/s. Its trajectory, with a slope of 68.4°, started at 67.6 km and ended at 30.2 km where the meteoroid traveled at 7.36 km/s. Approximately 50 g survived atmospheric entry. On February 7, 2023, two meteorites of 13.85 g and 8.21 g were recovered at the predicted site. Gamma spectrometry confirmed their young terrestrial age via short-lived cosmogenic radionuclides ⁵⁴Mn and ²²Na. Al-Khadhaf is thus the first camera-observed meteorite fall from Oman. Petrography and mineral composition classify it as an ordinary H5–6 S2 W1 chondrite. Its pre-impact orbit (<i>a</i> = 1.72 AU, <i>e</i> = 0.45, <i>i</i> = 4.36°) is consistent with asteroid-belt delivery, with both inner-belt and Koronis-family sources remaining plausible. The cosmic ray exposure age of 8.57 ± 1.2 Ma coincides with an exposure-age peak observed among H chondrites. Al-Khadhaf adds to the record of camera-observed falls, linking meteorite compositions to their solar system context via orbit calculations.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"522-547"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70110","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147566074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-ray computed tomography study of terrestrial analog cores in preparation for Mars sample return","authors":"Sophie Benaroya,&nbsp;Christopher D. K. Herd,&nbsp;David T. Flannery,&nbsp;Nicolas Randazzo","doi":"10.1111/maps.70104","DOIUrl":"https://doi.org/10.1111/maps.70104","url":null,"abstract":"<p>Mars Sample Return (MSR) is expected to transform planetary science by providing unprecedented access to pristine Martian material. Initial characterization in the sample receiving facility (SRF) will rely on nondestructive techniques such as X-ray computed tomography (XCT) to document the condition, distribution, and internal features of sealed core samples. To test XCT protocols in advance of MSR, we analyzed terrestrial analog cores collected during the Pilbara Sample Return campaign in Western Australia. Sedimentary and regolith samples were scanned at both whole-core and fragment scales to evaluate scan times, optimal energy conditions, and resolution limits. Our results demonstrate that XCT offers critical insights into fragment size distributions, internal banding, porosity, and fracture networks before sample opening, information that is essential for subsampling and preserving astrobiologically relevant textures. Integration with Raman spectroscopy, optical microscopy, and EPMA confirmed that XCT reliably identifies high-attenuation (high-μ) phases (e.g., oxides, sulfides) but cannot distinguish between common silicates, underscoring the need for multi-modal characterization. We also demonstrate how XCT data sets can be used to track sample mass, restore fragment orientation, and potentially reconstruct stratigraphic context. Updated sample mass estimates indicate that the MSR collection is sufficient to meet community science objectives, with required masses (12–15 g per core) well below expected returns. These results highlight XCT as a cornerstone of SRF pre-basic characterization, providing both immediate triage value and a foundation for long-term digital curation.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"405-426"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover","authors":"","doi":"10.1111/maps.70130","DOIUrl":"https://doi.org/10.1111/maps.70130","url":null,"abstract":"<p>\u0000 \u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure>\u0000 </p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70130","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147565275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Drelów, the 13th and latest meteorite fall in Poland—A typical L6 chondrite with shock veins","authors":"Addi Bischoff,&nbsp;Krzysztof Szopa,&nbsp;Jean-Alix Barrat,&nbsp;Stig Bartel,&nbsp;Jasper Berndt,&nbsp;Tommaso Di Rocco,&nbsp;Dieter Heinlein,&nbsp;Stephan Klemme,&nbsp;Tomasz Krzykawski,&nbsp;Björn Lehnert,&nbsp;Agnieszka Mirek,&nbsp;Andreas Pack,&nbsp;Markus Patzek,&nbsp;Marie Pichotta,&nbsp;Maximilian P. Reitze,&nbsp;Stefan Ruchti,&nbsp;Philippe Schmitt-Kopplin,&nbsp;Karl Wimmer,&nbsp;Mateusz Żmija","doi":"10.1111/maps.70106","DOIUrl":"https://doi.org/10.1111/maps.70106","url":null,"abstract":"<p>On Tuesday, February 18, 2025, at 18:04:14 local time, residents of Poland observed a bright fireball registered by many Polish fireball stations belonging to the Skytinel Network established a few months before by Mateusz Żmija. Thus, the meteoroid's orbit, atmospheric trajectory, and the strewn field were calculated, and over 70 fragments with a mass of approximately 3900 g were found near Drelów (Lublin Voivodeship, Poland; The Meteorite Bulletin Database, 2025). The samples were recovered by scientists, private searchers, and dealers, and many samples were offered immediately for collections and scientific research on the international meteorite market. Drelów is the 13th officially registered meteorite fall in Poland and is now officially classified as an L6 ordinary chondrite (S3, W0; The Meteorite Bulletin Database, 2025). Short-lived radionuclides were measured on a small sample shortly after recovery, and the results confirm that the meteorite specimen studied here derived from the bolide fireball event. The equilibrated and recrystallized type 6 character is also supported by the large plagioclase grains (An_9-12; with grains &gt;100 μm) and the homogeneous compositions of olivine (Fa_24.7±0.4) and low-Ca pyroxene (Fs_20.8±0.3). The olivine in Drelów is dominated by grains with planar fractures, but in the Münster samples a significant fraction of olivine shows weak mosaicism, indicating a moderately shocked S4 (C-S4) chondritic rock. Such mosaic olivine grains appear to lack in other fragments of Drelów requiring a S3 (C-S3) classification. Thus, Drelów experienced an equilibrium shock pressure close to the strength that defines the S3/S4 transition, which requires an equilibrium shock pressure of slightly above 20 GPa. The meteorite shows easily visible dark shock veins that cross-cut the bulk rock; the high-pressure phases maskelynite and wadsleyite were detected within or close to the veins. The O isotope data and the bulk chemical composition are consistent with the L-group membership. This is also confirmed by the density and the magnetic susceptibility measurements. The soluble organic compositions of Drelów are consistent with the profiles of unbrecciated L6 chondrites and comparable to Braunschweig (L6), showing molecular characteristics consistent with the complex shock and metamorphic history of the parent rock.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"466-486"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147564589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Moon's volcanic history revealed in glassy spherules from Apollo 17 soil 76501","authors":"Alexander A. Nemchin,&nbsp;Marc D. Norman,&nbsp;Martin J. Whitehouse,&nbsp;Evgenia Salin,&nbsp;Nicholas E. Timms,&nbsp;Tao Long,&nbsp;Xiaochao Che,&nbsp;Renaud Merle,&nbsp;Fred Jourdan,&nbsp;Tao Luo","doi":"10.1111/maps.70103","DOIUrl":"https://doi.org/10.1111/maps.70103","url":null,"abstract":"<p>Rapidly quenched droplets of pyroclastically erupted lava are common in lunar regolith at landing sites proximal to the maria. Here, we document the U-Pb chronologies, major element, and trace element compositions of picritic glassy particles from Apollo 17 regolith sample 76501. These particles are dominated by high-Ti compositions similar to those of the established Apollo 17 orange and black pyroclastic deposits, but the textures of some beads indicate slower cooling and/or equilibration at lower temperatures. Using a new approach to calibrate SIMS U-Pb isotopic analysis of vitrophyric beads, we show that their U-Pb ages are consistent with a single or closely timed multiple eruptions ~50–100 Ma younger than the 3752 ± 9 to 3758 ± 12 Ma crystalline mare basalts collected at this site. A few picritic beads with very low-Ti compositions may be younger, but their ages are not well defined and can be ~3.3–3.6 Ga.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"389-404"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical and petrographic re-evaluation of ungrouped iron meteorites from Western Australia","authors":"Ashley Rogers,&nbsp;Lucy Forman,&nbsp;Kai Rankenburg,&nbsp;Rachel Kirby,&nbsp;Martin Danišík,&nbsp;Victoria Cousins,&nbsp;Gretchen K. Benedix","doi":"10.1111/maps.70101","DOIUrl":"https://doi.org/10.1111/maps.70101","url":null,"abstract":"<p>Under the current classification scheme, ungrouped irons make up ~11% of all recognized iron meteorites. A further ~7% of iron meteorites are currently classified as simply “irons” and are yet to be fully classified. To potentially classify these meteorites, newer approaches, including either statistical modeling or advanced geochemical/petrological characterization, may be required. To approach this issue, we studied three ungrouped iron meteorites from Western Australia—Pennyweight, Prospector Pool, and Redfields. We conducted petrographical and geochemical analyses using a TESCAN Integrated Mineral Analyzer (TIMA), electron backscattered diffraction (EBSD), and laser ablation inductively coupled mass spectrometry (LA-ICP-MS). Through these analyses, the modal abundances, orientation relationships, and geochemical properties of the key metallic phases were determined. From this work, we have found that spot analyses of the kamacite and plessite are sufficient for iron meteorite classification, and these values can be used to reconstruct a “bulk” geochemical composition. Additionally, statistical data reduction (principal component analysis and t-distributed stochastic neighbor embedding) models have been used, in conjunction with the traditional logarithmic element plots, to assist with classification. Our results agree with previous studies that recommend the reclassification of Prospector Pool to the IIE group. Pennyweight may be a mesosiderite metal nodule with a metal composition closer to the IIIAB and IIE meteorites but has petrographical features similar to the IIE irons. It should remain ungrouped at this stage. Redfields is most likely a member of the IAB complex, potentially an IAB anomalous meteorite. Finally, the statistical models show a dichotomy between the IAB group and that the current iron meteorite groups seem to have more geochemical similarities than differences. Further analysis is required to assess the validity of the current classification scheme.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"444-465"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70101","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Combining universal-stage, backscatter electron imaging and electron backscatter diffraction for improved indexing of planar microstructures in quartz and plagioclase","authors":"Lidia Pittarello,&nbsp;Thomas Griffiths,&nbsp;Gerlinde Habler","doi":"10.1111/maps.70107","DOIUrl":"https://doi.org/10.1111/maps.70107","url":null,"abstract":"<p>Quartz and feldspar commonly develop planar microstructures due to shock metamorphism. These are generally investigated and indexed (identifying the crystallographic orientation along which they developed) using a universal stage (U-stage) on a petrographic microscope. However, the U-stage method alone can sometimes prove insufficient for correct indexing, for example, due to the size of microstructural features, or challenging, in the case of low symmetry minerals. Neither backscatter electron (BSE) imaging nor electron backscatter diffraction (EBSD) analysis can solve this problem individually for a flat surface, as both methods are limited to providing 2-D microstructural information. We propose a method combining contributions from U-stage, BSE imaging and EBSD. The combination and plotting of crystallographic orientation (from EBSD), U-stage measurements of planes and directions, and traces of planar microstructures (from BSE images) in a single reference frame allows the identification of the most probable orientations of features that could not be indexed by applying any single technique. The applicability and limitations of the proposed method were tested on selected shocked quartz and feldspar grains. The method proved to be successful and could be applied to study any 3-D planar features suspected to be aligned with crystallographic planes of an optically transparent host material.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"487-503"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147564591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reevaluating the impact origin of the Luna Structure in western India using mineralogy, highly siderophile elements, and Re-Os isotopes","authors":"Ajay Dev Asokan,&nbsp;Yogita Kadlag,&nbsp;Yash Srivastava,&nbsp;Khirod Kumar Das,&nbsp;Rumanshu Hazarika,&nbsp;James M. D. Day","doi":"10.1111/maps.70099","DOIUrl":"https://doi.org/10.1111/maps.70099","url":null,"abstract":"<p>The Holocene Luna Structure in western India has been claimed to be the fourth and youngest impact crater on the Indian subcontinent. The circular shape; the unusual mineralogy including high-temperature mineral phases such as kirschsteinite and wüstite; and the elevated abundance of highly siderophile elements (HSE: Os, Ir, Ru, Rh, Pt, and Pd) have been provided as evidence in favor of an impact origin. Here, we present new mineralogical, bulk rock geochemical data including isotope-dilution HSE abundances and ¹⁸⁷Re-¹⁸⁷Os compositions of the suspected Luna impactites. The samples are dense irregular nodules with undulated surface and flow-like structures and are glassy to extremely fine grained, with or without vesicles. The new HSE data show no Ir enrichment compared to upper continental crust. The radiogenic measured ¹⁸⁷Os/¹⁸⁸Os compositions (0.2289–0.7253) further rule out any extraterrestrial contribution in the suspected impactites. The observed high-temperature mineral assemblage shows similarity to that of iron-rich archaeological slags. We reinterpret the Luna Structure materials as slags that are likely associated with the Bronze Age in the Harappan Civilization and may have formed as a byproduct of copper smelting. Considering the new evidence, the Luna Structure of western India is not a meteorite impact crater.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"371-388"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147570248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Substitution of Fe3+ into anorthite in oxidized, Al-deficient ferrobasaltic systems with implications for the petrogenesis of angrite meteorites","authors":"Seann J. McKibbin,&nbsp;Dominique Tanner,&nbsp;Hugh St. C. O'Neill","doi":"10.1111/maps.70108","DOIUrl":"https://doi.org/10.1111/maps.70108","url":null,"abstract":"<p>Angrite meteorites are critically silica-undersaturated igneous rocks with high Ca/Al and Fe/Mg, along with depletion in volatile lithophile elements Na and K such that they crystallize anorthite along with olivine and calcic pyroxene. The anorthite in angrites contains substantial Fe, and in NWA 1670 and NWA 1296, it is present at major element levels correlated with deficiency in Al, suggesting abundant Fe₂O₃-Al₂O₃ exchange. One possible explanation is that these angrites had higher Fe³⁺ contents and their final interstitial melts crystallized under higher oxygen fugacities (<i>f</i>O₂) than those of other angrites. Here, we present melting experiments on angritic compositions over a range of <i>f</i>O₂ conditions. These experiments crystallized anorthite and Ca-rich pyroxene among other phases, showing that large substitutions of Fe³⁺ into Al-deficient anorthite (a “ferri-anorthite” component) are natural consequences of angritic melt crystallization at high <i>f</i>O₂. At face value, these experiments suggest substantial anorthite Fe₂O₃-Al₂O₃ exchange in NWA 1670 and NWA 1296 due to fractionated magmas crystallizing near the surface of the angrite parent body under oxidizing conditions. However, the inferred <i>f</i>O₂ is several log units higher than the iron-wüstite redox buffer and even higher than the fayalite–magnetite–quartz redox buffer. While extensive fractional crystallization might raise <i>f</i>O₂ by ~1 log unit by removal of ferrosilicates, it seems unlikely to explain the occurrence of this phase. The presence of Fe³⁺-rich anorthite might be attributed to rapid crystallization driving kinetic incorporation of excess Fe and disequilibrium degassing of SO₂ from a small dissolved sulfate component, leading to metastable preservation of this phase.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"61 3","pages":"427-443"},"PeriodicalIF":2.4,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147563123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}