{"created":"2023-07-25T11:02:15.912354+00:00","id":4478,"links":{},"metadata":{"_buckets":{"deposit":"9d266b30-7c34-4035-af73-5a0acf35078b"},"_deposit":{"created_by":4,"id":"4478","owners":[4],"pid":{"revision_id":0,"type":"depid","value":"4478"},"status":"published"},"_oai":{"id":"oai:nipr.repo.nii.ac.jp:00004478","sets":["1259:1260:1264:584:586"]},"author_link":["578","16340","7888"],"item_1_biblio_info_14":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1989-10","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"74","bibliographicPageStart":"55","bibliographicVolumeNumber":"2","bibliographic_titles":[{"bibliographic_title":"Proceedings of the NIPR Symposium on Antarctic Meteorites"}]}]},"item_1_creator_8":{"attribute_name":"著者名(英)","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Tomeoka, Kazushige","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Kojima, Hideyasu","creatorNameLang":"en"}],"nameIdentifiers":[{}]},{"creatorNames":[{"creatorName":"Yanai, Keizo","creatorNameLang":"en"}],"nameIdentifiers":[{}]}]},"item_1_description_1":{"attribute_name":"ページ属性","attribute_value_mlt":[{"subitem_description":"P(論文)","subitem_description_type":"Other"}]},"item_1_description_12":{"attribute_name":"抄録(英)","attribute_value_mlt":[{"subitem_description":"A petrographic and mineralogical study of Yamato-86720 (Y-86720) shows that it may be a CM carbonaceous chondrite that has experienced a considerably different alteration history from most CM chondrites. Y-86720 has an unusually high abundance of troilite (～9 vol%); most troilite occurs in submicron to micron grains dispersed throughout the meteorite. Ca-Mg carbonates and minor Fe-Ni metal, mostly taenite, are present, but magnetite and PCP are absent. This meteorite contains chondrules and aggregates that were completely replaced by optically translucent materials, presumably phyllosilicates. Thus Y-86720 was probably extensively affected by aqueous alteration; the degree of alteration may be the highest of the CM chondrites. Matrix consists largely of fine grains of Mg-Fe olivine, a nearly amorphous Si-Mg-Fe-rich material, and an Fe-rich material; the latter may be ferrihydrite. Phyllosilicates are rare. The textures suggest that the olivine and the Si-Mg-Fe-rich material were produced by alteration of phyllosilicates by heating. The replacement products of chondrules and aggregates show lower (Mg+Fe)/(Si+Al) ratios than serpentine and relatively high Na contents (up to 2.0wt% as Na_2O), suggesting the presence of not only serpentine but another type of phyllosilicate. However, the replacement products show consistently high analytical totals; thus they may have been dehydrated and partially altered to anhydrous phases. These results suggest that Y-86720 has experienced mild thermal metamorphism after the aqueous alteration; it appears to have been heated above 500℃ in a reduced condition. Most fine-grained troilite probably segregated from matrix during the metamorphic process. Many of the troilites are replaced by a ferrihydrite-like material; thus, Y-86720 may have been affected by additional mild aqueous alteration after the thermal metamorphism.","subitem_description_type":"Other"}]},"item_1_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15094/00004478","subitem_identifier_reg_type":"JaLC"}]},"item_1_publisher_22":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"National Institute of Polar Research"}]},"item_1_source_id_13":{"attribute_name":"雑誌書誌ID","attribute_value_mlt":[{"subitem_source_identifier":"AA10784627","subitem_source_identifier_type":"NCID"}]},"item_1_text_10":{"attribute_name":"著者所属(英)","attribute_value_mlt":[{"subitem_text_language":"en","subitem_text_value":"Mineralogical Institute, Faculty of Science, University of Tokyo"},{"subitem_text_language":"en","subitem_text_value":"National Institute of Polar Research"},{"subitem_text_language":"en","subitem_text_value":"National Institute of Polar Research"}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"1989-10-01"}],"displaytype":"detail","filename":"KJ00000036284.pdf","filesize":[{"value":"2.4 MB"}],"format":"application/pdf","licensetype":"license_6","mimetype":"application/pdf","url":{"label":"KJ00000036284","url":"https://nipr.repo.nii.ac.jp/record/4478/files/KJ00000036284.pdf"},"version_id":"7c993f79-cf0b-479b-999c-f2ebd8e920ba"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"Yamato-86720: A CM carbonaceous chondrite having experienced extensive aqueous alteration and thermal metamorphism","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Yamato-86720: A CM carbonaceous chondrite having experienced extensive aqueous alteration and thermal metamorphism"}]},"item_type_id":"1","owner":"4","path":["586"],"pubdate":{"attribute_name":"公開日","attribute_value":"1989-10-01"},"publish_date":"1989-10-01","publish_status":"0","recid":"4478","relation_version_is_last":true,"title":["Yamato-86720: A CM carbonaceous chondrite having experienced extensive aqueous alteration and thermal metamorphism"],"weko_creator_id":"4","weko_shared_id":4},"updated":"2023-07-25T12:20:10.137421+00:00"}