Meteoritics & Planetary Science最新文献

{"title":"EH6 enstatite chondrites Northwest Africa 7976 and Northwest Africa 12945: Implications for EH chondrite metamorphism","authors":"Mabel L. Gray,&nbsp;Michael K. Weisberg,&nbsp;Steven J. Jaret,&nbsp;Denton S. Ebel","doi":"10.1111/maps.14287","DOIUrl":"https://doi.org/10.1111/maps.14287","url":null,"abstract":"<p>The enstatite chondrite class is known to have complex thermal histories, often interpreted to include impact melting and shock metamorphism. Highly equilibrated (type 6) EH group enstatite chondrites are rare and thought to have formed through collisional heating. We studied two EH6 chondrites, NWA 7976 and NWA 12945, for their textural, chemical, and mineralogical characteristics. The samples we studied contain subhedral to anhedral grains of enstatite and plagioclase, suggesting solid-state recrystallization. They show low degrees of shock and no evidence of shock melting. Additionally, the ubiquitous occurrence of daubréelite exsolution lamellae in troilite and the Ni content of schreibersite suggest slow cooling at greater burial depths in the parent body, rather than rapid cooling as a result of an impact event. Based on the characteristics and scarcity of type 6 EH chondrites, and the ubiquitous shock effects and melt rocks in the enstatite chondrite class, we conclude that the unshocked NWA 7976 and NWA 12945 were formed by heat derived from impact melt sheets, analogous to contact metamorphism.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 1","pages":"51-63"},"PeriodicalIF":2.2,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114754","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 reappraisal of the petrogenesis of Apollo 17 lunar dunites 72415-72417: Relics of the deep lunar mantle?","authors":"K. K. Bhanot,&nbsp;H. Downes,&nbsp;B. G. Rider-Stokes,&nbsp;E. S. Jennings,&nbsp;M. Anand,&nbsp;J. F. Snape,&nbsp;M. J. Whitehouse","doi":"10.1111/maps.14269","DOIUrl":"https://doi.org/10.1111/maps.14269","url":null,"abstract":"<p>Lunar dunite samples 72415–72417, collected by Apollo 17 astronauts from a South Massif boulder in the Taurus–Littrow valley, are crushed breccias composed of several types of olivine- and clinopyroxene-rich clasts, some of which are (or contain) intergrowths of Cr-spinel and pyroxenes or plagioclase. Among the clasts are ellipsoidal symplectites of Cr-spinel and pyroxene, up to 300 μm in diameter, which have bulk compositions consistent with those of olivine + garnet. These symplectites are inferred to originally have been olivine + Mg-Cr-rich garnet (pyrope–uvarovite) that formed deep in the lunar mantle and were subsequently transported closer to the lunar surface (spinel- or plagioclase-peridotite stability fields), perhaps during gravitationally driven overturn. Abundant microsymplectite (30 μm diameter) intergrowths of Cr-spinel and pyroxene inside olivine grains, many associated with inclusions of plagioclase and augite, formed during a later decompression event (perhaps excavation to the lunar surface). These inclusions have not previously been recorded in these samples and could be responsible for earlier reports of igneous zoning in olivine. Electron backscatter diffraction data show evidence of high shock pressures (&gt;50 GPa), which are inferred to have occurred during the impact which excavated the dunites from the shallow anorthite-bearing lunar mantle. Apatite veinlets post-date the shock metamorphism and have been dated to 3983 ± 72 Ma and 3913 ± 118 Ma by the U–Pb method. This age is consistent with that inferred for the Imbrium impact basin, suggesting that the dunite was finally excavated from the mantle during formation of the Imbrium basin.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 12","pages":"3129-3149"},"PeriodicalIF":2.2,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142861308","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":"Rapid colonization of a space-returned Ryugu sample by terrestrial microorganisms","authors":"Matthew J. Genge,&nbsp;Natasha Almeida,&nbsp;Matthias Van Ginneken,&nbsp;Lewis Pinault,&nbsp;Louisa J. Preston,&nbsp;Penelope J. Wozniakiewicz,&nbsp;Hajime Yano","doi":"10.1111/maps.14288","DOIUrl":"https://doi.org/10.1111/maps.14288","url":null,"abstract":"<p>The presence of microorganisms within meteorites has been used as evidence for extraterrestrial life, however, the potential for terrestrial contamination makes their interpretation highly controversial. Here, we report the discovery of rods and filaments of organic matter, which are interpreted as filamentous microorganisms, on a space-returned sample from 162173 Ryugu recovered by the Hayabusa 2 mission. The observed carbonaceous filaments have sizes and morphologies consistent with microorganisms and are spatially associated with indigenous organic matter. The abundance of filaments changed with time and suggests the growth and decline of a prokaryote population with a generation time of 5.2 days. The population statistics indicate an extant microbial community originating through terrestrial contamination. The discovery emphasizes that terrestrial biota can rapidly colonize extraterrestrial specimens even given contamination control precautions. The colonization of a space-returned sample emphasizes that extraterrestrial organic matter can provide a suitable source of metabolic energy for heterotrophic organisms on Earth and other planets.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 1","pages":"64-73"},"PeriodicalIF":2.2,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14288","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114755","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":"Petrogenesis of lunar granulitic breccia meteorites Northwest Africa 15062 and 15063","authors":"Zhipeng Xia,&nbsp;Baochen Yang,&nbsp;Bowen Si,&nbsp;Guozhu Chen,&nbsp;Xi Wang,&nbsp;Hongyi Chen,&nbsp;Chuantong Zhang,&nbsp;Bingkui Miao","doi":"10.1111/maps.14285","DOIUrl":"https://doi.org/10.1111/maps.14285","url":null,"abstract":"<p>We present petrology and mineralogy for two lunar granulitic breccia meteorites that were detected in Northwest Africa (NWA), the samples NWA 15062 and NWA 15063. The fragments primarily consist of plagioclase and olivine mineral clasts, with minor amounts of anorthosite clasts and one troctolite clast. The anorthosite clasts are dominated by plagioclase/maskelynite, with minor olivine and pyroxene. A troctolite clast, composed of olivine and maskelynite, occurs in NWA 15063. The olivine clasts display mosaic extinction and usually have a homogeneous Mg-rich composition. However, all olivine mineral clasts exhibit two distinct ranges of their major element composition (Mg#: 85–88 and 77–78, respectively). Large individual plagioclase clasts show heterogeneous compositions (Ab content: 2.5–4.8) and have different Raman peak positions in different domains. The matrix of the meteorites appears semitransparent and is composed of olivine and pyroxene aggregates associated with maskelynite, constituting a granoblastic texture. Pyroxenes of the matrix are dominantly enstatites, associated with a few augites. Both meteorite samples exhibit shock-induced melt veins ranging from 50 to 200 μm width. These melt veins traverse the entire samples and contain rare, very fine-grained (2–3 μm) Mg-rich olivine clasts (Mg# = 90–93) and mafic silicate glass. Some Cr-spinel grains exhibit slight compositional zonation, characterized by a magnesium-rich core (Mg# = 56, Cr# = 23) and Cr-rich rims (Mg# = 50, Cr# = 28), with decomposition at the edges. The significantly differing Mg# contents of the mafic silicate minerals in the matrix, lithic clasts, and mineral clasts of the two meteorites indicate a diverse origin of the clasts. Based on their petrology, mineral chemistry, and bulk composition, NWA 15062 and NWA 15063 are classified as anorthositic troctolitic granulitic polymict breccia. Textural evidence suggests that the parent rocks of NWA 15062 and NWA 15063 were affected by high pressure of up to 30 GPa during impact-induced shock metamorphism, causing crystal structure deformation in olivine and the transformation of plagioclase to maskelynite. During cooling from peak temperatures of 1600–1700°C, the coarse-grained maskelynite mineral clasts were partially devitrified, and the granoblastic texture of the matrix was developed. Mg-rich anorthosite was formed before this shock event. Cr-spinel was formed in a troctolitic melt, which was probably differentiated after the crystallization of anorthite and magnesium-rich olivine. However, the possibility of the formation of the Mg-rich melt through interaction with the lunar anorthositic crust cannot be ruled out. The meteorite NWA 15062/15063 strongly resembles the textural, chemical, and mineralogical characteristics of the NWA 5744 meteorite group. Therefore, we interpret the two samples as a new member of the NWA 5744 meteorite group.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 1","pages":"32-50"},"PeriodicalIF":2.2,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143114358","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":"2007 Service Award for John Schutt","authors":"Ralph P. Harvey","doi":"10.1111/maps.14281","DOIUrl":"https://doi.org/10.1111/maps.14281","url":null,"abstract":"&lt;p&gt;It is an honor to introduce (albeit 17 years late) the recipient of the Meteoritical Society's 2007 Service Award, Dr. John Schutt. I have had the great privilege of working with John, or “Johnny Alpine” as he has often been called, for almost 40 years. After all that time, I have an endless supply of anecdotes I could share, but a great number of you reading this have your own, so I will restrain myself. Suffice it to say that my first meeting with John was when the late Bill Cassidy (founder of the US Antarctic Search for Meteorites program, or ANSMET) sent me to his dorm room in McMurdo, where I found a sweating, smelly, heaving John deep in the grasp of that marvelous contagion we call “the McMurdo Crud.” Ever the gentleman, he coughed into his hands for 15–20 seconds, then with a very crooked grin offered me his hand in friendship. Things have gone uphill ever since.&lt;/p&gt;&lt;p&gt;As is standard fare for these awards, many of you either know John or have at least heard of him. What is different this time is a matter of intensity—many of us have literally, at one moment or another, trusted John with our lives. No offense, Barringer and Leonard and Nier Awards, but Johnny Alpine is someone who deserves respect on an entirely different level.&lt;/p&gt;&lt;p&gt;So what are John's accomplishments? Let us start with meteoritics. John was the first dedicated mountaineer to work with the US Antarctic Search for Meteorites program, starting in 1980 and continuing to this day. That puts him at well-over 40 field seasons years and counting, of involvement with ANSMET. He has spent at least 5 full years of his life camping out on the East Antarctic ice sheet. The result is that John can probably claim to be the world's premier meteorite recovery specialist, having recovered more meteorites than any single person in history. ANSMET does not keep track of who found individual specimens in any given season, but making reasonable estimates, I'd put the number for John somewhere around 4000 or 5000. For perspective, this is about two times the cumulative number of known meteorites found before systematic Antarctic collection began. Similarly, I think no individual in history has personally recovered more samples of Mars; in some sense, he is to Mars what the Apollo astronauts were to the Moon. And perhaps the most astonishing feature of this body of work is that every single sample has been made available to the world's science community free of charge, and curated at the highest level, with neither John nor any other ANSMET personnel getting favored access to the specimens.&lt;/p&gt;&lt;p&gt;In addition to his work as ANSMET's mountaineer he has contributed tens of thousands of hours beyond those “normal” duties. John single-handedly dragged ANSMET into mapping find locations, ultimately created AMLAMP (Antarctic Meteorite Location and Mapping Program), which preserves and makes available the geographical information related to Antarctic meteorite finds. This was done originally withou","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 12","pages":"E7-E8"},"PeriodicalIF":2.2,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142860790","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.14022","DOIUrl":"https://doi.org/10.1111/maps.14022","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 11","pages":"i"},"PeriodicalIF":2.2,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14022","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142641848","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":"Microscopic mineralogy of zoned pyroxene in NWA 12522: Implications for the crystallization histories of the shergottites","authors":"Zhuang Guo,&nbsp;Yu Zhu,&nbsp;Yang Li,&nbsp;Ian M. Coulson,&nbsp;Xiongyao Li,&nbsp;Jianzhong Liu","doi":"10.1111/maps.14283","DOIUrl":"https://doi.org/10.1111/maps.14283","url":null,"abstract":"<p>Basaltic shergottites are the most abundant rock type of Martian meteorites, and pyroxene grains within shergottites commonly show a zoned structure. Here, the detailed microscopic mineralogical characteristics of patchy zoned pyroxene in basaltic shergottite NWA 12522 were investigated by a combination of scanning electron microscopy, electron microprobe, Raman spectroscopy, and transmission electron microscopy. The results show that the cores of zoned pyroxene in NWA 12522 have a homogeneous Mg# value and consist mainly of augite and pigeonite. By contrast, the rim of zoned pyroxene is extremely ferroan and can be further divided into two regions based on quite distinct mineralogy and textures (i.e., far-core and near-core pyroxene rims). The near-core rim shows narrow exsolution lamellae (~35 nm) that were cross-cut by thin pigeonite veinlets and contain abundant nano-sized particles of metastable pyroxferroite and pigeonite. Only relatively coarse exsolution lamellae (~80 nm) were observed in the far-core pyroxene rim regions. The distinct mineralogical characteristics of the pyroxene rims and cores in NWA 12522 imply different crystallization conditions, and the homogeneous Mg-rich pyroxene cores should have slowly crystallized from magma within a deep-seated chamber, followed by an overgrown evolved melt on these pyroxene cores during their ascent to the Martian surface, and disequilibrium crystallization of nano-sized metastable phase (pyroxferroite) occurred in the near-core region. The abnormally low ΣREE contents and steep REE pattern (high Yb/La ratio) of the pyroxene rims in NWA 12522 imply that merrillite should have crystallized prior to the pyroxene rims, making the residual melt become REE-depleted and HREE-enriched.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 12","pages":"3340-3352"},"PeriodicalIF":2.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142860311","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 diversity of temperature and pressure conditions recorded by zircon within suevite from Ries crater, Germany","authors":"A. C. Stadermann,&nbsp;T. M. Erickson,&nbsp;L. B. Seifert,&nbsp;Y. Chang,&nbsp;Z. Zeszut,&nbsp;T. J. Zega,&nbsp;Z. D. Michels,&nbsp;J. J. Barnes","doi":"10.1111/maps.14282","DOIUrl":"https://doi.org/10.1111/maps.14282","url":null,"abstract":"<p>The temperature and pressure conditions experienced by rocks during an impact event can be constrained using petrologic and microstructural analysis and is crucial to providing ground truth to the impact cratering process. Suevite is a polymict, impact melt-bearing breccia, specific to Ries crater in Germany. There are competing models for suevite formation and emplacement, such as clastic flows pushed out of the crater rim or ejecta plume fallback. Knowledge of the temperature and pressure pathways recorded by grains within the suevite can help distinguish between these and other models. The accessory phase zircon (ZrSiO₄) and its high-pressure polymorph reidite are particularly useful in such circumstances as they are highly refractory minerals that can record the high-temperature and/or high-pressure conditions of an impact event. Here, we present evidence for a wide array of temperature and pressure conditions recorded in zircon grains within a single thin section of suevite. Zircons in this study range from unshocked to highly shocked (&gt;53 GPa), and record temperatures more than 1673°C. These findings confirm previous studies concluding that suevites contain material exposed to very diverse pressure and temperature conditions during initial shock compression and excavation but do not, as a whole, experience extreme temperatures (&gt;1673°C) or pressures (&gt;30 GPa).</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 12","pages":"3322-3339"},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142860690","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":"Positive correlation between shock stage and petrologic type in ordinary chondrites: Implications for the internal structures and thermal histories of ordinary-chondrite parent asteroids","authors":"Alan E. Rubin","doi":"10.1111/maps.14284","DOIUrl":"https://doi.org/10.1111/maps.14284","url":null,"abstract":"<p>H, L, and LL chondrites all exhibit positive correlations between mean shock stage and petrologic type. At a given shock energy, hot samples exhibit more intense shock features than cold samples. After the ordinary-chondrite (OC) parent asteroids were collisionally disrupted, jumbled, and gravitationally reassembled, the correlations between mean shock stage and petrologic type may have resulted from stochastic collisions into material of different temperatures that were randomly distributed in the near-surface regions of the rubble-pile asteroids. Late-stage processes including shock events and post-shock annealing affected the preexisting correlations to only minor degrees. This model, combined with literature data, permits the following scenario: Each principal OC asteroid initially had an onion-shell structure with deeply buried type 6 materials cooling slowly, yielding young closure ages in Pb-phosphate data. The OC bodies were disrupted at ~60 Ma, locking in the Pb-phosphate record of the onion-shell structure. The H-chondrite parent body was collisionally disrupted somewhat later than the L or LL bodies and was thus somewhat cooler at the time of disruption. In the OC asteroidal rubble piles, materials of different petrologic types cooled at similar rates through ~500°C, precluding a correlation between petrologic type and metallographic cooling rate. Shortly after rubble-pile formation, materials of higher petrologic types remained hotter than materials of lower petrologic types. The hotter materials recorded more intense shock features from the common meteoroid flux, leading to positive correlations in each OC asteroid between petrologic type and mean shock stage. The cooler H-chondrite materials manifested a lower range in mean shock stage.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 1","pages":"17-31"},"PeriodicalIF":2.2,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14284","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143112967","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":"A Cryogenian impact structure lurking in the shadows of northern Sweden","authors":"C. Alwmark,&nbsp;G. G. Kenny,&nbsp;S. Alwmark,&nbsp;P. Minde,&nbsp;J. Plado,&nbsp;S. Hietala,&nbsp;M. J. Whitehouse","doi":"10.1111/maps.14280","DOIUrl":"https://doi.org/10.1111/maps.14280","url":null,"abstract":"<p>Here we report on findings for four rock samples with melt texture found in a gravel pit within a glaciofluvial deposit near the small town of Kitkiöjärvi in northernmost Sweden. The samples are comprised of granitic clasts embedded in a brown fine-grained melt matrix. The samples all contain quartz grains and/or clasts exhibiting multiple sets of planar deformation features oriented parallel to crystallographic planes characteristic of shock metamorphism. The samples also contain Former Reidite In Granular Neoblastic (FRIGN) zircon. We therefore conclude that the investigated samples represent impact melt rock. We interpret a U-Pb concordia age of 658.9 ± 6.9 Ma (Cryogenian) derived using secondary-ion mass spectrometry analysis of shocked zircon, as the best estimate for the age of the impact event that formed the melt rocks. Zircon grains from two of the samples yield younger lower intercept ages, raising the possibility that the samples came from multiple impact events of different ages. Although we cannot exclude this possibility, we interpret the younger ages from the clast-rich melt rocks to reflect non-impact-related Pb loss events and suggest that all samples likely came from the same structure. Analysis of the glaciofluvial history of the region, along with the relatively high frequency of finds (five in total, as one similar melt rock was found in the pit in 2018), points to a short-distance glacial transportation of the samples from the southwest. Since there are no known impact structures in Sweden within that area and/or of similar age, we conclude that an old (the oldest known yet) impact structure in Sweden potentially is yet to be discovered somewhere in the vicinity of the gravel pit.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"59 12","pages":"3305-3321"},"PeriodicalIF":2.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.14280","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142860226","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}