{"created":"2023-07-27T06:26:30.756150+00:00","id":10257,"links":{},"metadata":{"_buckets":{"deposit":"e5419e2a-2915-41e5-9cd3-421018165eda"},"_deposit":{"created_by":3,"id":"10257","owners":[3],"pid":{"revision_id":0,"type":"depid","value":"10257"},"status":"published"},"_oai":{"id":"oai:kanazawa-u.repo.nii.ac.jp:00010257","sets":["934:935:937"]},"author_link":["15350","14980"],"item_4_biblio_info_8":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2002-10-01","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"10","bibliographicPageEnd":"684","bibliographicPageStart":"671","bibliographicVolumeNumber":"108","bibliographic_titles":[{"bibliographic_title":"地質学雑誌"}]}]},"item_4_description_21":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"丹後半島中央部に分布する八鹿累層は前期中新世の日本海拡大時に噴出した玄武岩～安山岩質溶岩および火砕岩からなる.それらの斑晶組み合わせばType1がOl-Cpx-Pl,Type2がOl-Opx-Pl,Type3がOl-Pl,そしてType4がPlであり,FeO^*/MgOはこの順に増加するがSiO_2はほぼ一定のソレアイト的分化傾向を示す.これらはLILEおよびLREEに富み,ZrやZr/Yが高く,Nbに涸渇し,大陸性島弧火山岩の特徴を示す.新発見のType1ピクライト質玄武岩はMgO(12wt.%),Ni(300ppm),Cr(1,100ppm)に富み,スピネルのCr/(Al+Cr)が0.64-0.84で他のType1玄武岩(0.49-0.59)より高いが,液相濃集元素組成や他の鉱物化学組成はそれらと同様である.このピクライト質玄武岩は,他の八鹿累層火山岩類と同じ給源マントルから,若干含水条件下で,温度上昇による高い部分溶融程度で形成されたと考えられる.同様なピクライトは活動的背弧海盆の沖縄トラフ周辺にもあり,日本海拡大初期の高温マントルの上昇を示唆する. The Yoka Formation in the central part of the Tango Peninsula consists of early Miocene lavas and pyroclastic rocks of basaltic and andesitic composition, which extruded during the Japan Sea opening. These volcanic rocks are grouped into five types on the basis of phenocryst assemblages; Type 1 is olivine (Ol)-clinopyroxene (Cpx)-plagioclase (Pl), Type 2 is Ol- orthopyro-xene (Opx)-Pl, Type 3 is Ol-Pl, Type 4 is only Pl (large phenocrysts), and Type 5 is Cpx-Opx-Pl±Ol. The bulk-rock FeO^*/MgO (^*total iron as FeO) increases from Type 1 to Type 4 with almost constant SiO_2, indicating a tholeiitic fractionation trend, al-though Type 5 shows relatively high SiO_2. All these rocks are characterized by enrichment of large ion lithophile elements (LILEs) and light rare earth elements (LREEs), high Zr and Zr/Y, and depletion of Nb, indicating continental island-arc basalt signature. The newly found picritic basalt is classified into Type 1, and has more MgO (12 wt.%), Ni (300 ppm) and Cr (1100 ppm) than other Type 1 basalts. It is depleted in HFSEs but is slightly enriched in LILEs compared to other Type 1 basalts, al-though they are chemically very close (e.g. equal in SiO_2). It also shows the same mineral chemistry as other Type 1 basalts except for its chromian spinel, which shows distinctly higher Cr/(Cr±Al) (0.64-0.84) than that of other Type 1 basalts (0.49-0.59). These facts suggest that the picritic basalt was formed through a higher degree of partial melting under slightly hydrous condition from almost the same source mantle as for other Type 1 basalts. A closely resembling picrite has been reported from the Okinawa Trough area, where active back-arc rifting is taking place, suggesting upheaval of the high-temperature mantle in the early stage of the Japan Sea opening.","subitem_description_type":"Abstract"}]},"item_4_description_5":{"attribute_name":"提供者所属","attribute_value_mlt":[{"subitem_description":"金沢大学大学院自然科学研究科","subitem_description_type":"Other"}]},"item_4_publisher_17":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"日本地質学会"}]},"item_4_rights_23":{"attribute_name":"権利","attribute_value_mlt":[{"subitem_rights":"日本地質学会の許諾を得て登録"}]},"item_4_source_id_11":{"attribute_name":"NCID","attribute_value_mlt":[{"subitem_source_identifier":"AN00141768","subitem_source_identifier_type":"NCID"}]},"item_4_source_id_9":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"0016-7630","subitem_source_identifier_type":"ISSN"}]},"item_4_version_type_25":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"石渡, 明"}],"nameIdentifiers":[{},{},{}]},{"creatorNames":[{"creatorName":"今坂, 美絵"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-10-03"}],"displaytype":"detail","filename":"AN00141768-ISHIWATARI-108.pdf","filesize":[{"value":"1.7 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"AN00141768-ISHIWATARI-108.pdf","url":"https://kanazawa-u.repo.nii.ac.jp/record/10257/files/AN00141768-ISHIWATARI-108.pdf"},"version_id":"ff8a98ca-b5b0-4f47-889e-16b30ca694d3"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"journal article","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"京都府丹後半島,中新統八鹿累層のピクライト質玄武岩","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"京都府丹後半島,中新統八鹿累層のピクライト質玄武岩"},{"subitem_title":"Picritic basalt from the Miocene Yoka Formation in the Tango Peninsula, Kyoto Prefecture, southwestern Japan","subitem_title_language":"en"}]},"item_type_id":"4","owner":"3","path":["937"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-10-03"},"publish_date":"2017-10-03","publish_status":"0","recid":"10257","relation_version_is_last":true,"title":["京都府丹後半島,中新統八鹿累層のピクライト質玄武岩"],"weko_creator_id":"3","weko_shared_id":-1},"updated":"2023-07-28T01:42:26.620391+00:00"}