Meteoritics & Planetary Science最新文献

{"title":"Cover","authors":"","doi":"10.1111/maps.14203","DOIUrl":"https://doi.org/10.1111/maps.14203","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":"60 5","pages":"i"},"PeriodicalIF":2.2,"publicationDate":"2025-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14203","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930211","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":"Pairing and classification assessment of CM chondrites from the Meteorite Hills, Transantarctic Mountains","authors":"K. Righter,&nbsp;M. Welby,&nbsp;H. C. Bates,&nbsp;A. J. King,&nbsp;P. F. Schofield,&nbsp;J. Schutt,&nbsp;R. Harvey,&nbsp;J. Karner,&nbsp;B. Rougeux,&nbsp;K. Pando,&nbsp;C. Satterwhite","doi":"10.1111/maps.14353","DOIUrl":"https://doi.org/10.1111/maps.14353","url":null,"abstract":"<p>The Meteorite Hills dense collection area in the Transantarctic Mountains has yielded 1130 meteorites over several ANSMET field seasons. Twenty-three CM carbonaceous chondrites were recovered as part of the 2000–2001 and 2001–2002 field seasons. Many of these CMs have unique or rare features, but most are small (&lt;50 g), making their preservation of highest priority, so material can be available for future researchers. One major contributor to preservation is knowing which samples are paired with others. Because CM chondrites are fine grained and petrographic features are subtle, standard petrography is not as helpful in classification. To strengthen the understanding of pairing and classification, we initiated a focused study of the 23 CM chondrites recovered from Meteorite Hills. Combining magnetic susceptibility (MS), modal mineralogy as determined using X-ray diffraction (XRD), and published information about a subset of samples, we have reassessed the classification and pairing. Many samples have MS log <i>χ</i> values between 3.7 and 3.9, but there are a few exceptions such as MET 00432 (4.85), MET 01076 and 77 (4.06 and 4.63, respectively), and MET 01073 (3.21). Fifteen of the samples exhibit intermediate to high levels of aqueous alteration with phyllosilicate fractions (PSF) of 0.88–0.93. A trio of samples exhibit even higher levels of alteration with PSFs of 0.96–0.98. Find locations and cosmic ray exposure (CRE) ages of these two groups are similar and the latter very short at 0.1–0.2 Ma, raising the possibility that they are all part of the same heterogeneous fall. Since the three heavily altered samples are rare and have distinctive mineralogy relative to other MET CMs, they should be preserved regardless of whether they are from one large fall or two separate falls. Two samples (MET 01076 and MET 01077) contain a much greater fraction of olivine and pyroxene, have longer CRE ages, and most likely are heated CM chondrites. Three samples are unpaired and have unique characteristics: MET 00432 has a high magnetite fraction and other mineralogical and chemical properties comparable to C2 ungrouped chondrites such as Tagish Lake and Tarda, while MET 001087 (PSF = 0.77) and MET 00633 (PSF = 0.76) are less aqueously altered than the other meteorites, with the former in particular showing a significant tochilinite peak in its XRD pattern. Although MET 00633 could arguably be part of the larger pairing group of samples given its similar find location, we recommend keeping it unpaired given its distinct mineralogy.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1249-1262"},"PeriodicalIF":2.2,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930262","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":"Hydration and dehydration of CM chondrites revealed by X-ray diffraction combined with textural observations and compositional data","authors":"Naoya Imae,&nbsp;Makoto Kimura,&nbsp;Akira Yamaguchi","doi":"10.1111/maps.14348","DOIUrl":"https://doi.org/10.1111/maps.14348","url":null,"abstract":"<p>The in-plane rotation method is used to obtain X-ray random diffraction (XRD) patterns of polished thin sections of 10 CM chondrites. The samples include five intermediately altered CM chondrites with subtypes 2.6–2.3, two heavily altered CM chondrites with subtype 2.0 and three with secondary heating after hydration (Y 980036, Y 980051, and Jbilet Winselwan). These CM chondrites are compared to each other as well as four previously analyzed CM meteorites of subtypes 3.0–2.8 and 2.0. The same thin sections also underwent textural observations and compositional analyses. Unheated CM chondrites display systematic mineralogical changes. As the alteration degree increases from subtypes 3.0–2.0, the presence of olivine and clinoenstatite decreases, while that of serpentines increases. The abundance of tochilinite significantly increases from 2.7 to 2.3 but then decreases from 2.3 to 2.0. Subtype 2.0 consists of relatively more Mg-rich serpentine than Fe-rich serpentine (cronstedtite). The XRD identified only Mg-serpentine from Jbilet Winselwan, suggesting selective decomposition of Fe-rich serpentine (cronstedtite), while all hydrous minerals in Y 980036 and Y 980051 decomposed. Additionally, all three CM chondrites with secondary heating after hydration show stage II or category B heating by the peak metamorphic temperature of 300–750°C. Compared to previous studies using XRD, the combination of XRD with the textural and compositional analyses using the same polished thin section, avoiding the preparation for powder samples, is a straightforward approach to characterize hydrated chondritic samples. The approach is nondestructive and can be correlated with SEM/EPMA, unlike previous XRD studies that required powdered samples.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1194-1215"},"PeriodicalIF":2.2,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14348","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930505","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":"Evaluating 14C and 14C/10Be terrestrial age dating systems for meteorites using experimental data and model calculations","authors":"Mohammad Tauseef,&nbsp;Ingo Leya,&nbsp;Jérôme Gattacceca,&nbsp;Sönke Szidat,&nbsp;Régis Braucher,&nbsp;Pascal M. Kruttasch,&nbsp;Anna Zappatini,&nbsp;ASTER Team","doi":"10.1111/maps.14355","DOIUrl":"https://doi.org/10.1111/maps.14355","url":null,"abstract":"<p>This study presents a refined approach to determine ¹⁴C saturation activities and ¹⁴C/¹⁰Be saturation activity ratios in chondritic meteorites with the goal to improve terrestrial age dating. By combining new model calculations for ¹⁰Be, ¹⁴C, and cosmogenic (²²Ne/²¹Ne)_cos, along with experimental data from 17 freshly fallen chondrites, we established reliable correlations for ¹⁴C production rates and ¹⁴C/¹⁰Be production rate ratios as a function of (²²Ne/²¹Ne)_cos. The experimental data agree with the model calculations, and they fully confirm that ¹⁴C production rates and ¹⁴C/¹⁰Be production rate ratios depend on shielding. Constrained correlations describe the experimental data for all shielding conditions and all ordinary chondrites mostly within the uncertainties given by the model. The new correlations therefore provide a significant improvement compared to the earlier approaches, in which average meteorite-type-dependent ¹⁴C production rates and average ¹⁴C/¹⁰Be production rate ratios were assumed. Ignoring the shielding dependence introduces a size-dependent bias into the terrestrial age database. This study enables the determination of shielding-corrected ¹⁴C saturation activities and ¹⁴C/¹⁰Be production rate ratios to calculate shielding-corrected terrestrial ages for meteorites reducing or eliminating a size bias in the database. In addition, this novel approach enables to give reliable uncertainty estimates of within 15% for the ¹⁴C and ¹⁴C-¹⁰Be terrestrial ages.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1263-1283"},"PeriodicalIF":2.2,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930534","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":"Chemical, isotopic (O, He, U), and petrological characteristics of a slowly cooled enriched gabbroic shergottite, Northwest Africa 13134","authors":"Lee Saper,&nbsp;Yang Liu,&nbsp;Michael A. Kipp,&nbsp;David Burney,&nbsp;Chi Ma,&nbsp;Francois L. H. Tissot,&nbsp;Edward Young,&nbsp;Jonathan Treffkorn,&nbsp;Kenneth A. Farley","doi":"10.1111/maps.14345","DOIUrl":"https://doi.org/10.1111/maps.14345","url":null,"abstract":"<p>Northwest Africa 13134 is a coarse-grained gabbro with an oxygen isotopic composition consistent with a Martian origin and is classified as an enriched shergottite based on its bulk trace element abundances and bulk La/Yb ratio of 1.53. The meteorite is composed of a framework of large pyroxene rods up to 6 mm in longest dimension (64% by area) with interstitial maskelynite (formerly plagioclase; 28% by area). Minor phases include merrillite and apatite, Fe-Ti oxides, and Fe-sulfides; trace phases such as baddeleyite, tranquillityite, fayalitic olivine, silica, and a felspathic phase are observed in evolved mesostasis pockets and partially crystallized magmatic inclusions in minerals. Individual pyroxene rods display a distinctive patchy Ca zoning pattern of juxtaposed low-Ca (pigeonite) and high-Ca (augite) patches with a common crystallographic orientation indicating epitaxial growth. Low-Ca pigeonite is the volumetrically dominant pyroxene phase (~70% of exposed pyroxene) and was the primary liquidus phase, followed closely by augite. Plagioclase crystallized along with the other minor phases from the residual melt between cumulus pyroxene rods. Pyroxenes display ubiquitous exsolution lamellae with typical widths and spacings of 1–2 μm. Sulfide grains are characterized by flame-shaped lamellar intergrowths of hexagonal pyrrhotite (Fe_0.90S) and slightly metal-deficient pyrrhotite (Fe_0.98S), along with minor pentlandite and chalcopyrite. The pyroxene and sulfide microtextures suggest that the gabbro experienced slow and protracted subsolidus cooling. Ilmenite-oxide pairs imply an oxygen fugacity of ~1 log unit below the fayalite–magnetite–quartz buffer at a closure T ≈ 875°C. Collectively, the texture and bulk composition suggest that Northwest Africa 13134 represents a slowly cooled and coarsely crystalline portion of a solidified magma body similar to the source of the enriched basaltic shergottites. Magnetite occurs locally as veins crosscutting pyrrhotite grains and in oxide–phosphate symplectites observed at merrillite–apatite phase boundaries. The presence of magnetite in the sample suggests that at various stages of cooling, the gabbro interacted with relatively oxidized fluids, which could be of deuteric or exogeneous origin. A cosmic-ray exposure age of 2.8–4.0 Ma was calculated based on ³He measured in pyroxene grain separates and overlaps with other shergottites. Finally, we present the first bulk uranium isotope measurement of a Martian meteorite: δ²³⁸U = −0.22 ± 0.10‰ and δ²³⁴U_sec = +9.57 ± 0.35‰. These values indicate slight excesses in heavy U but overlap with the distribution of U isotope compositions of the Earth and other solar system materials.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1119-1150"},"PeriodicalIF":2.2,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930456","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":"Cover","authors":"","doi":"10.1111/maps.14201","DOIUrl":"https://doi.org/10.1111/maps.14201","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":"60 4","pages":"i"},"PeriodicalIF":2.2,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14201","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809624","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":"Spheroidized plessite in Vaca Muerta: Formation mechanism and its implications for mesosiderites genesis and cooling history","authors":"Laura Noel García,&nbsp;Frederic Danoix,&nbsp;Martina Ávalos,&nbsp;Pouyan Shen,&nbsp;María Eugenia Varela","doi":"10.1111/maps.14352","DOIUrl":"https://doi.org/10.1111/maps.14352","url":null,"abstract":"<p>The presence of spheroidized plessite (SP) in mesosiderites was recently reported in the literature. This finding coupled with the poor understanding of this plessite variant, motivated us to investigate its formation process and evaluate its implications in assessing the previous proposals concerning mesosiderites' genesis and cooling history. SP consists of spherulitic taenite particles irregularly distributed, usually surrounded by carbides, and embedded in a kamacite matrix. It has been reported in iron meteorites containing graphite, carbides, and pearlitic plessite (PP), especially in the IAB main group and the sLL and sLH subgroups. From the combination of X-ray tomography, electron backscatter diffraction, energy-dispersive spectrometry, and atom probe tomography in three samples of Vaca Muerta mesosiderite (A1, low to moderate metamorphism) from the ICATE (Argentina) collection of meteorites, we were able to identify a common crystallographic orientation between spheroids and retained taenite, the absence of PP and the carbon depletion in the metallic portion contiguous to the spheroids, and the high volumetric connectivity of the metallic portion. Based on these findings: (i) SP likely grew at the expense of pearlite lamellae, with their absence resulting from complete consumption after an extraordinarily slow cooling rate, probably succeeding a deep burial in a breccia of rock fragments. (ii) Carbon introduction would have followed plessite formation in mesosiderites at a temperature low enough to prevent carbon solid-state diffusion. (iii) Metal would have been poured in silicates, which favors the collision model between a differentiated asteroid and a molten core for mesosiderite genesis.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1236-1248"},"PeriodicalIF":2.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930142","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":"Volume measurement of microparticles using SEM photogrammetry and 3-D reconstruction","authors":"Y. Zheng,&nbsp;X. Yang,&nbsp;M. Valdes,&nbsp;A. M. Davis,&nbsp;P. R. Heck","doi":"10.1111/maps.14351","DOIUrl":"https://doi.org/10.1111/maps.14351","url":null,"abstract":"<p>In this paper, we introduce a method for volume measurement of microparticles that includes scanning electron microscope photogrammetry with 3-D model construction. Our results show that our method limits the volume uncertainty to ±10%, which is a significant improvement compared to previous methods (which likely overestimated volume by 100%–200%). We also discuss how the size, morphology, and porosity of the sample can affect the uncertainty of volume measurement. We find that our method can have a significant impact on cosmic ray exposure age determinations based on noble gas concentration, with implications for our understanding of cosmic ray irradiation of refractory minerals in the early solar system and presolar grains in the interstellar medium.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1227-1235"},"PeriodicalIF":2.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14351","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930141","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":"Tamdakht: A Moroccan ordinary chondrite fall with an uncommon fusion crust","authors":"Larbi Zennouri,&nbsp;Hasnaa Chennaoui Aoudjehane,&nbsp;Luigi Folco,&nbsp;Taha Shisseh,&nbsp;Abderrazak El Albani,&nbsp;Arnaud Mazurier,&nbsp;Mohamed Hassan Leili","doi":"10.1111/maps.14349","DOIUrl":"https://doi.org/10.1111/maps.14349","url":null,"abstract":"<p>Tamdakht meteorite is the most massive observed fall in Morocco with a total recovered mass of ~500 kg. Most of the specimens investigated in this study are covered by a well-developed primary fusion crust with thickness that reaches up to 12 mm. Macroscopic investigations reveal the development of complex fusion crust features indicative of unusual entry conditions. In some specimens, pieces of the primary fusion crust are missing, and the newly exposed areas developed a thinner fusion crust, which suggests that the former were removed during the late stages of the meteoroid's flight. Meteorite fragments are enclosed in the primary fusion crust, implying a potential intershower debris transfer prior to the dark flight and that the broken pieces were retained by the viscous fusion crust. X-ray tomographic and backscattered electron imaging shows that the primary fusion is irregular in thickness and consists of three layers. The outer layer is mainly composed of magnetite that formed as a result of the reaction of atmospheric oxygen with Fe in the melt produced by heating. The middle layer consists of zoned olivine phenocrysts, large vesicles, and metal and sulfide grains. The innermost layer displays a lower degree of melting and contains tiny vesicles, as well as metal and iron sulfides in the form of blebs and veins invading the substrate. The textural, mineralogy, and the compositional variation of Tamdakht's fusion crust imply a change in the degassing degree, temperature, and reaction with atmospheric oxygen from the surface inward.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1216-1226"},"PeriodicalIF":2.2,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930201","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":"A Potůčky fragment of the Steinbach IVA-an meteorite: Implications from the trace-element composition of the constituent phases","authors":"Alexandre V. Andronikov,&nbsp;Irina E. Andronikova,&nbsp;Ondrej Pour,&nbsp;Petr Bohdalek","doi":"10.1111/maps.14347","DOIUrl":"https://doi.org/10.1111/maps.14347","url":null,"abstract":"<p>We have analyzed in situ mineral phases in a Potůčky fragment of the stony-iron IVA-an meteorite Steinbach for trace-element compositions. The studied fragment contains silicate grains (pyroxene and tridymite) interspersed with grains of metal (kamacite, plessite, and taenite) displaying Widmanstätten pattern and troilite. Multiple inclusions of chromite, troilite, and bi-mineral troilite + taenite assemblages were observed within some pyroxene grains. The data on variations in trace-element compositions in different meteorite phases are consistent with a number of models, suggesting the involvement of several processes in the generation of the lithologies presently observed in the Potůčky meteorite. These processes might have involved fractional crystallization of silicate liquid, collision, impact, shock melting, and cooling. As a result of such processes, specific trace-element composition of different mineral phases was formed. Trace-element compositions of metals and sulfides from the Potůčky meteorite are very similar to those for minerals from the LL ordinary chondrite, suggesting LL-like asteroid as a parent body for the Potůčky (IVA-an) precursor material.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 5","pages":"1166-1193"},"PeriodicalIF":2.2,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143930314","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}