Rachel S. Kirby, Penelope L. King, Andrew G. Tomkins
{"title":"IIE铁与普通、F和HH球粒陨石之间关系的统计研究","authors":"Rachel S. Kirby, Penelope L. King, Andrew G. Tomkins","doi":"10.1111/maps.70040","DOIUrl":null,"url":null,"abstract":"<p>It has been proposed that IIE iron meteorites formed through impact processes on a parent body that was composed of either the H chondrites or a much-debated fourth ordinary chondrite group, the HH chondrites. To resolve this debate, we have compiled a large dataset for the ordinary chondrites, low-fayalite ungrouped chondrites, and IIE irons, and undertaken a statistical analysis to determine if: (1) the current classification of ordinary chondrite groups is statistically appropriate; and (2) the IIE irons are related to H chondrites or if they represent a distinct group that formed on a “HH” chondrite parent body. We demonstrate that the current classification system based on petrography and olivine and orthopyroxene chemistry is appropriate for the H, L, and LL chondrites. We define a fourth “F chondrite” group consisting of eight, previously ungrouped, very low-Fa Type 3 and 4 chondrites. Statistical analysis of Δ<sup>17</sup>O data alone cannot distinguish between the H chondrites and IIE irons, nor between the L and LL chondrites. Furthermore, statistical analyses are unable to distinguish H chondrites from IIE irons in all measures (mineral chemistry, chondrule size, bulk Δ<sup>17</sup>O, Ge and Mo isotopic compositions, and bulk siderophile element abundances in metal); there is no evidence for a “HH” chondrite group. These results are consistent with formation of IIE iron meteorites through impact melting and near-surface metal segregation on the H chondrite parent body. This genetic link between H chondrites and IIE irons allows us to understand the geochemical and petrological changes that occurred during planetary formation and evolution.</p>","PeriodicalId":18555,"journal":{"name":"Meteoritics & Planetary Science","volume":"60 10","pages":"2376-2400"},"PeriodicalIF":2.4000,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70040","citationCount":"0","resultStr":"{\"title\":\"A statistical investigation into relationships between the IIE irons and the ordinary, F and “HH” chondrites\",\"authors\":\"Rachel S. Kirby, Penelope L. King, Andrew G. Tomkins\",\"doi\":\"10.1111/maps.70040\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p>It has been proposed that IIE iron meteorites formed through impact processes on a parent body that was composed of either the H chondrites or a much-debated fourth ordinary chondrite group, the HH chondrites. To resolve this debate, we have compiled a large dataset for the ordinary chondrites, low-fayalite ungrouped chondrites, and IIE irons, and undertaken a statistical analysis to determine if: (1) the current classification of ordinary chondrite groups is statistically appropriate; and (2) the IIE irons are related to H chondrites or if they represent a distinct group that formed on a “HH” chondrite parent body. We demonstrate that the current classification system based on petrography and olivine and orthopyroxene chemistry is appropriate for the H, L, and LL chondrites. We define a fourth “F chondrite” group consisting of eight, previously ungrouped, very low-Fa Type 3 and 4 chondrites. Statistical analysis of Δ<sup>17</sup>O data alone cannot distinguish between the H chondrites and IIE irons, nor between the L and LL chondrites. Furthermore, statistical analyses are unable to distinguish H chondrites from IIE irons in all measures (mineral chemistry, chondrule size, bulk Δ<sup>17</sup>O, Ge and Mo isotopic compositions, and bulk siderophile element abundances in metal); there is no evidence for a “HH” chondrite group. These results are consistent with formation of IIE iron meteorites through impact melting and near-surface metal segregation on the H chondrite parent body. This genetic link between H chondrites and IIE irons allows us to understand the geochemical and petrological changes that occurred during planetary formation and evolution.</p>\",\"PeriodicalId\":18555,\"journal\":{\"name\":\"Meteoritics & Planetary Science\",\"volume\":\"60 10\",\"pages\":\"2376-2400\"},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2025-09-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://onlinelibrary.wiley.com/doi/epdf/10.1111/maps.70040\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Meteoritics & Planetary Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://onlinelibrary.wiley.com/doi/10.1111/maps.70040\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Meteoritics & Planetary Science","FirstCategoryId":"89","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/maps.70040","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
A statistical investigation into relationships between the IIE irons and the ordinary, F and “HH” chondrites
It has been proposed that IIE iron meteorites formed through impact processes on a parent body that was composed of either the H chondrites or a much-debated fourth ordinary chondrite group, the HH chondrites. To resolve this debate, we have compiled a large dataset for the ordinary chondrites, low-fayalite ungrouped chondrites, and IIE irons, and undertaken a statistical analysis to determine if: (1) the current classification of ordinary chondrite groups is statistically appropriate; and (2) the IIE irons are related to H chondrites or if they represent a distinct group that formed on a “HH” chondrite parent body. We demonstrate that the current classification system based on petrography and olivine and orthopyroxene chemistry is appropriate for the H, L, and LL chondrites. We define a fourth “F chondrite” group consisting of eight, previously ungrouped, very low-Fa Type 3 and 4 chondrites. Statistical analysis of Δ17O data alone cannot distinguish between the H chondrites and IIE irons, nor between the L and LL chondrites. Furthermore, statistical analyses are unable to distinguish H chondrites from IIE irons in all measures (mineral chemistry, chondrule size, bulk Δ17O, Ge and Mo isotopic compositions, and bulk siderophile element abundances in metal); there is no evidence for a “HH” chondrite group. These results are consistent with formation of IIE iron meteorites through impact melting and near-surface metal segregation on the H chondrite parent body. This genetic link between H chondrites and IIE irons allows us to understand the geochemical and petrological changes that occurred during planetary formation and evolution.
期刊介绍:
First issued in 1953, the journal publishes research articles describing the latest results of new studies, invited reviews of major topics in planetary science, editorials on issues of current interest in the field, and book reviews. The publications are original, not considered for publication elsewhere, and undergo peer-review. The topics include the origin and history of the solar system, planets and natural satellites, interplanetary dust and interstellar medium, lunar samples, meteors, and meteorites, asteroids, comets, craters, and tektites. Our authors and editors are professional scientists representing numerous disciplines, including astronomy, astrophysics, physics, geophysics, chemistry, isotope geochemistry, mineralogy, earth science, geology, and biology. MAPS has subscribers in over 40 countries. Fifty percent of MAPS'' readers are based outside the USA. The journal is available in hard copy and online.