Meteoritics & Planetary Science最新文献

{"title":"Micro- and nanoscale studies of insoluble organic matter and C-rich presolar grains in Murchison and Sutter's Mill in preparation for Bennu sample analysis","authors":"A. N. Nguyen,&nbsp;S. J. Clemett,&nbsp;K. Thomas-Keprta,&nbsp;C. M. O'D. Alexander,&nbsp;D. P. Glavin,&nbsp;J. P. Dworkin,&nbsp;H. C. Connolly Jr,&nbsp;D. S. Lauretta","doi":"10.1111/maps.14254","DOIUrl":"https://doi.org/10.1111/maps.14254","url":null,"abstract":"<p>Samples of B-type asteroid (101955) Bennu returned by the Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) spacecraft will provide unique insight into the nature of carbonaceous asteroidal matter without the atmospheric entry heating or terrestrial weathering effects associated with meteoritic samples. Some of the Bennu samples will undergo characterization by X-ray computed tomography (XCT). To protect the pristine nature of the samples, it is important to understand any adverse effects that could result from irradiation during XCT analysis. We analyzed acid-insoluble residues produced from two powdered samples of the Murchison carbonaceous chondrite, one control and one XCT-scanned, to assess the impact on insoluble organic matter (IOM) and presolar grains. Using a suite of in situ analytical techniques (field-emission scanning electron microscopy, optical and ultraviolet fluorescence microscopy, microprobe two-step laser mass spectrometry, and nanoscale secondary ion mass spectrometry), we found that the two residues had indistinguishable chemical, molecular, and isotopic signatures on the micron to submicron scale, indicating that an X-ray dosage of 180 Gy (the maximum dose to be used during preliminary examination of Bennu materials) did not damage the IOM and presolar grains. To explore the use of acid-insoluble residues to infer parent body processes in preparation for Bennu sample analysis, we also analyzed a residue produced from the Sutter's Mill carbonaceous chondrite. Multiple lines of evidence, including severely degraded UV fluorescence signatures and D-rich hotspots, indicate that the parent body of Sutter's Mill was heated to &gt;400°C. This heating event was likely short lived because the abundance of presolar SiC grains, which are destroyed by thermal metamorphism and prolonged oxidation, was consistent with those in Murchison and other unheated chondrites. The results of these in situ analyses of acid-insoluble residues from Murchison and Sutter's Mill provide complementary detail to bulk analyses.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 10","pages":"2831-2850"},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430390","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":"Magmatic evolution of KREEP-free lunar meteorite Asuka-881757 inferred from sector-zoned clinopyroxene, pyroxene symplectites, and thermodynamic modeling","authors":"Y. Srivastava,&nbsp;A. Basu Sarbadhikari,&nbsp;A. Yamaguchi,&nbsp;A. Takenouchi,&nbsp;J. M. D. Day,&nbsp;T. Ubide","doi":"10.1111/maps.14257","DOIUrl":"https://doi.org/10.1111/maps.14257","url":null,"abstract":"<p>Lunar basaltic meteorite Asuka-881757 (A-881757), a member of the source crater paired YAMM meteorites (Yamato-793169, A-881757, Miller Range 05035 and Meteorite Hills 01210), provides information on potassium-rare earth element-phosphorous (KREEP)-free magmatic sources within the Moon. Asuka-881757 is an unbrecciated and Fe-rich (Mg# 36) gabbro with coarse pyroxene (2–8 mm) and plagioclase (1–3 mm). The coarse pyroxene preserves mm-scale, near-complete hour-glass sector zoning with strong Ca and Fe partitioning, similar to some Fe-rich Apollo basalts. In contrast to the most Mg-rich Apollo basalts, A-881757 contains various types of symplectites (~8 vol%) formed by the breakdown of pyroxferroite due to slow cooling, resembling a few extreme Fe-rich (Mg# <span></span><math>\u0000 <mrow>\u0000 <mo>≤</mo>\u0000 </mrow></math>40) Apollo basalts. Petrographic observations and thermodynamic modeling suggest crystallizing in the order: Fe-poor pyroxenes (Mg# 58–55) → co-crystallized plagioclase and Fe-rich pyroxenes (Mg# 49–20) → late-stage assemblage including Fe-augite, Fayalite, and Fe-Ti oxides. Combining phase stability at variable <i>P–T</i> with petrographic observations, the minimum depth of formation of the A-881757 parent magma can be constrained to between 60 and 100 km. KREEP-free basalts (such as A-881757 and the YAMM meteorites) originated from a relatively shallow mantle source and later underwent polybaric crystallization that occurred prior to eruption at the lunar surface. In contrast, the Apollo mare basalts mostly crystallized within lava flows from relatively deeper-seated mantle sources. The crystallization of A-881757 and other YAMM meteorites is unlike most Apollo basalts from the Procellarum KREEP terrane, and likely represent hidden cryptomare basalts close to lunar surface.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 11","pages":"2938-2955"},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642438","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":"Kinetic analysis of dehydration/dehydroxylation from carbonaceous chondrites by in situ heating experiments under an infrared microscope","authors":"Mengyan Zheng,&nbsp;Yoko Kebukawa,&nbsp;Yuka Hayashi,&nbsp;Kensei Kobayashi","doi":"10.1111/maps.14259","DOIUrl":"https://doi.org/10.1111/maps.14259","url":null,"abstract":"<p>CI, CM, and CR carbonaceous chondrites contain hydrous minerals, indicating that their parent bodies underwent aqueous alteration at low temperatures. Some of these chondrites, such as heated CM, CI, and CY chondrites, experienced thermal dehydration by impacts or solar radiation after aqueous alteration. This study conducted heating experiments on carbonaceous chondrites and evaluated their dehydration/dehydroxylation kinetics in an effort to explain the thermal history of the parent asteroids of heated carbonaceous chondrites using their degrees of dehydration/dehydroxylation of hydrous minerals. Murchison (CM2.5) and Ivuna (CI1), relatively primitive (having not undergone thermal alteration) carbonaceous chondrites, were used as starting materials. Weakening in the OH band at ~3680 cm⁻¹ (2.72 μm) with isothermal heating at 350–500°C (Murchison) and 450–525°C (Ivuna) were observed under in situ infrared spectroscopy (FT-IR) equipped with a heating stage. To determine the rate constants, the decrease in the OH band was fitted using kinetic models such as first-order reactions, two-dimensional diffusion, and three-dimensional diffusion. The apparent activation energies and frequency factors were determined using the Arrhenius equation. Time–temperature transformation diagrams were drawn to represent the decrease in the OH-band intensity as a function of temperature and heating duration. Such kinetic approaches can provide constraints on the temperature and time of the dehydration/dehydroxylation processes and enable us to estimate long-term effects from experiments in the laboratory within a short time.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 11","pages":"2981-2997"},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14259","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642531","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":"Discovery of fossil micrometeorites from the Deccan trap intertrappeans","authors":"V. P. Singh,&nbsp;N. G. Rudraswami,&nbsp;Nittala V. Chalapathi Rao,&nbsp;Matthew J. Genge,&nbsp;M. Pandey,&nbsp;S. Sreekuttan,&nbsp;S. Chattopadhaya","doi":"10.1111/maps.14256","DOIUrl":"https://doi.org/10.1111/maps.14256","url":null,"abstract":"<p>The Cretaceous–Paleogene (K-Pg) boundary represents the extinction of ~70% of species, a prominent Chicxulub impact event and Deccan volcanism. This work reports the first attempt to extract the micrometeorites (MMs) from the Deccan intertrappean horizons. Eighty-one spherical particles were studied for their morphological, textural, and chemical characteristics. Intact cosmic spherules with ferromagnesian silicates (6) and Fe-Ni oxide (7) compositions correspond to MMs from the deep sea and Antarctica. Silicate and Fe-Ni spherules in this study showcase remarkable preservation, a testament to the highly favorable conditions present. Fe spherules (38) with iron oxide compositions exhibit diagenetic alteration during preservation. Textural analysis of 30 Fe spherules reveals a dendritic, interlocking pattern and slightly elevated Mn content, suggesting these may be fossilized I-type MMs. However, eight Fe spherules with blocky and cubical granular textures resemble oxidized pyrite spherules. Al-Fe-Si spherules (30) possess a significant enrichment of Al and Si within their Fe-oxide-dominated composition. Group-I Al-Fe-Si spherules (15) display zoned Al-Fe-Si oxide composition, dendritic Mg-Cr spinel grains, and aerodynamic features, all indicative of impact spherules. The finding of these impact spherules from sampled Deccan intertrappean layer raises the possibility that these paleosols were deposited during the Chicxulub impact event, the only identified impact event with global distribution during the Deccan volcanism time frame. This unique location provides an opportunity for the simultaneous collection of well-preserved MMs, impact, and volcanic spherules. The exceptional preservation of the studied MMs is likely due to a combination of non-marine environments, atypical climatic conditions, and rapid deposition. This study further investigates the potential role of cosmic dust flux in the K-Pg extinction event. We propose that the enhanced cosmic dust flux, a likely scenario during the K-Pg boundary period, synergistically mixing with impact dust in the upper atmosphere, may have intensified and extended the harsh climatic conditions at the K-Pg boundary. Subsequently, the deposition of this dust, enriched in bioavailable iron, on Earth's surface might have contributed to the swift recovery of life and environmental conditions.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 11","pages":"2922-2937"},"PeriodicalIF":2.2,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142642437","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":"Cosmic-ray exposure age accumulated in near-Earth space: A carbonaceous chondrite case study","authors":"Patrick M. Shober,&nbsp;Marc W. Caffee,&nbsp;Phil A. Bland","doi":"10.1111/maps.14246","DOIUrl":"https://doi.org/10.1111/maps.14246","url":null,"abstract":"<p>This study investigates the expected cosmic-ray exposure (CRE) of meteorites if they were to be ejected by a near-Earth object, that is, from an object already transferred to an Earth-crossing orbit by an orbital resonance. Specifically, we examine the CRE ages of CI and CM carbonaceous chondrites (CCs), which have some of the shortest measured CRE ages of any meteorite type. A steady-state near-Earth carbonaceous meteoroid probability density function is estimated based on the low-albedo near-Earth asteroid population, including parameters such as the near-Earth dynamic lifetime, the impact probability with the Earth, and the orbital parameters. This model was then compared to the orbits and CRE ages of the five CC falls with precisely measured orbits: Tagish Lake, Maribo, Sutter's Mill, Flensburg, and Winchcombe. The study examined two meteoroid ejection scenarios for CI/CM meteoroids: Main Belt collisions and ejections in near-Earth space. The results indicated that applying a maximum physical lifetime in near-Earth space of 2–10 Myr to meteoroids and eliminating events evolving onto orbits entirely detached from the Main Belt (<i>Q</i> &lt; 1.78 au) significantly improved the agreement with the observed orbits of carbonaceous falls. Additionally, the CRE ages of three of the five carbonaceous falls have measured CRE ages one to three orders of magnitude shorter than expected for an object originating from the Main Belt with the corresponding semi-major axis value. This discrepancy between the expected CRE ages from the model and the measured ages of three of the carbonaceous falls indicates that some CI/CM meteoroids are being ejected in near-Earth space. This study proposes a nuanced hypothesis involving meteoroid impacts and tidal disruptions as significant contributors to the ejection and subsequent CRE age accumulation of CI/CM chondrites in near-Earth space.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 10","pages":"2695-2717"},"PeriodicalIF":2.2,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142430248","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":"86th Annual Meeting of the Meteoritical Society (2024)","authors":"","doi":"10.1111/maps.14240","DOIUrl":"https://doi.org/10.1111/maps.14240","url":null,"abstract":"","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 S1","pages":"A1-A468"},"PeriodicalIF":2.2,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14240","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077864","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":"86th Annual Meeting of the Meteoritical Society (2024)","authors":"","doi":"10.1111/maps.14239","DOIUrl":"https://doi.org/10.1111/maps.14239","url":null,"abstract":"","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 S1","pages":"i-xlii"},"PeriodicalIF":2.2,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077863","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":"86th Annual Meeting of the Meteoritical Society (2024)","authors":"","doi":"10.1111/maps.14252","DOIUrl":"https://doi.org/10.1111/maps.14252","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":"59 S1","pages":"1"},"PeriodicalIF":2.2,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14252","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142077862","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.14016","DOIUrl":"https://doi.org/10.1111/maps.14016","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":"59 8","pages":"i"},"PeriodicalIF":2.2,"publicationDate":"2024-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141991694","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":"Chondrule sizes within the CM carbonaceous chondrites and measurement methodologies","authors":"C. J. Floyd,&nbsp;S. Benito,&nbsp;P.-E. Martin,&nbsp;L. E. Jenkins,&nbsp;E. Dunham,&nbsp;L. Daly,&nbsp;M. R. Lee","doi":"10.1111/maps.14250","DOIUrl":"10.1111/maps.14250","url":null,"abstract":"<p>The sizes of chondrules are a valuable tool for understanding relationships between meteorite groups and the affinity of ungrouped chondrites, documenting temporal/spatial variability in the solar nebula, and exploring the effects of parent body processing. Many of the recently reported sizes of chondrules within the CM carbonaceous chondrites differ significantly from the established literature average and are more closely comparable to those of chondrules within CO chondrites. Here, we report an updated analysis of chondrule dimensions within the CM group based on data from 1937 chondrules, obtained across a suite of CM lithologies ranging from petrologic subtypes CM2.2 to CM2.7. Our revised average CM chondrule size is 194 μm. Among the samples examined, a relationship was observed between petrologic subtype and chondrule size such that chondrule long-axis lengths are greater in the more highly aqueously altered lithologies. These findings suggest a greater similarity between the CM and CO chondrites than previously thought and support arguments for a genetic link between the two groups (i.e., the CM-CO clan). Using the 2-D and 3-D data gathered, we also apply numerous stereological corrections to examine their usefulness in correcting 2-D chondrule measurements within the CM chondrites. Alongside this analysis, we present the details of a standardized methodology for 2-D chondrule size measurement to facilitate more reliable inter-study comparisons.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 10","pages":"2769-2788"},"PeriodicalIF":2.2,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14250","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141927342","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}