Variety and genesis of the pyroxene-bearing S-and I-type granitoids from the Hidaka Metamorphic Belt, Hokkaido, northern Japan

Toshiaki Shimura, Masaaki Owada, Yasuhito Osanai, Masayuki Komatsu, Hiroo Kagami

研究成果: Contribution to journalArticle査読

1 被引用数 (Scopus)

抄録

The hig-dT/dP-type Hidaka Metamorphic Belt in Hokkaido, northern Japan, represents a tilted crustal section of a magmatic arc of Tertiary age. The highest metamorphic grades reached are granulite facies, and the syn-metamorphic granitic rocks are widely distributed in this metamorphic terrane. The granitic rocks are mainly tonalitic and granodioritic in composition, and are classified into peraluminous (S-type) and metaluminous (I-type) granitoids. A large amount of pyroxene-bearing S-type tonalites (garnet-orthopyroxene tonalite) is distributed in the Niikappu river region in the northern part of the Hidaka Metamorphic Belt. Pyroxene-bearing I-type tonalite (two-pyroxene hornblende tonalite) bodies are also distributed in this area. The pyroxene-bearing tonalites are classified into several sub-types on the basis of their field occurrence, texture, mineral assemblage and geochemical features. Homogeneous I H -and S H -type tonalite are thought to represent original magmas, i.e. those which have been generated by partial melting of mafic metamorphic rocks and pelitic-psammitic metamorphic rocks, respectively. Model calculations assuming batch partial melting indicate that possible restites are garnet-two-pyroxene mafic granulite for I H -type and garnet-orthopyroxene aluminous granulite for S H -type. The unexposed lowermost crust of the 'Hidaka crust' is thought to be composed of garnet-twopyroxene mafic granulite, garnet-orthopyroxene aluminous granulite and metagabbros.

本文言語英語
ページ(範囲)161-179
ページ数19
ジャーナルSpecial Paper of the Geological Society of America
389
DOI
出版ステータス出版済み - 1 1 2004

All Science Journal Classification (ASJC) codes

  • Geology

フィンガープリント 「Variety and genesis of the pyroxene-bearing S-and I-type granitoids from the Hidaka Metamorphic Belt, Hokkaido, northern Japan」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル