ID | 6992 |
Title Transcription | オガサワラ チチジ マムジンイワ ノ キサイ ガンセキ ガクテキ ケンキュウ : ムジン イワ マクラジョウ ヨウガン ノ スイチョク ヘンカ
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Title Alternative (English) | Petrological Characteristics of Boninite from Chichijima Island, Ogasawara, Japan : Vertical Petrological Diversity of Boninite Pillow Lava
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File | |
language |
jpn
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Attribute |
Natural Science
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Author |
Taku, Masahiro
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Description | Chichijima, Ogasawara Islands is the place where boninite has been exposed most voluminously all over the world. Moreover, it is “type locality” of boninite. Boninite is high-magnesian andesite (HMA) which is a primary andesite basis of its high Mg, Ni and Cr content, directly derived from mantle. We did detailed research and sampling of boninite based on geological map of Chichijima (Umino and Nakano, 2007) and clarified and classified petrographic characteristics of boninite. Uminio (1986) classified aphyric boninite from Chichijima into five types: (I) olivine (ol) + clinoenstatite (cen) + bronzaite (brz); (II) ol + brz; (III) brz; (IV) brz + pigeonite (pig) + augite (aug); (V) cen + brz. We can classified the type (II) of Umino (1986) divided into four types by phenocryst and micro-phenocryst assemblage. They are Type AI (phenocryst: (ol + serpentine (ser)) / brz ≧1 and micro-phenocryst: brz / clinopyroxene (cpx) ≧1), Type AII (phenocryst: (ol + serpentine (ser)) / brz ≧1 and micro-phenocryst: brz / clinopyroxene (cpx) < 1), Type BI (phenocryst: (ol + serpentine (ser)) / brz < 1 and micro-phenocryst: brz / clinopyroxene (cpx) ≧1 ) and Type BII (phenocryst: (ol + serpentine (ser)) / brz <1 and micro-phenocryst: brz / clinopyroxene (cpx) <1 ). It has been understood that the above four types rock appears in respective height in the pillow lava bed.
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Journal Title |
島根大学教育学部紀要
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Volume | 43
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Start Page | 123
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End Page | 135
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ISSN | 18808581
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Published Date | 2009-12-25
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NCID | AA12171265
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DOI(SelfDOI) | |
Publisher | 島根大学教育学部
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Publisher Aalternative | Faculty of Education Shimane University
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NII Type |
Departmental Bulletin Paper
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Format |
PDF
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Text Version |
出版社版
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OAI-PMH Set |
Faculty of Education
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他の一覧 |