Petrogenesis of the Kaikomagatake granitoid pluton in the Izu Collision Zone, central Japan: Implications for transformation of juvenile oceanic arc into mature continental crust

Satoshi Saito, Makoto Arima, Takashi Nakajima, Kenichiro Tani, Takashi Miyazaki, Ryoko Senda, Qing Chang, Toshiro Takahashi, Yuka Hirahara, Jun Ichi Kimura

研究成果: Contribution to journalArticle査読

9 被引用数 (Scopus)

抄録

The Miocene Kaikomagatake pluton is one of the Neogene granitoid plutons exposed in the Izu Collision Zone, which is where the juvenile Izu-Bonin oceanic arc is colliding against the mature Honshu arc. The pluton intrudes into the Cretaceous to Paleogene Shimanto accretionary complex of the Honshu arc along the Itoigawa-Shizuoka Tectonic Line, which is the collisional boundary between the two arcs. The pluton consists of hornblende-biotite granodiorite and biotite monzogranite, and has SiO 2 contents of 68-75 wt%. It has high-K series compositions, and its incompatible element abundances are comparable to the average upper continental crust. Major and trace element compositions of the pluton show well-defined chemical trends. The trends can be interpreted with a crystal fractionation model involving the removal of plagioclase, biotite, hornblende, quartz, apatite, and zircon from a potential parent magma with a composition of ~68 wt% SiO 2. The Sr isotopic compositions, together with the partial melting modeling results, suggest that the parent magma is derived by ~53% melting of a hybrid lower crustal source comprising ~30% Shimanto metasedimentary rocks of the Honshu arc and ~70% K-enriched basaltic rocks of the Izu-Bonin rear-arc region. Together with previous studies on the Izu Collision Zone granitoid plutons, the results of this study suggest that the chemical diversity within the parental magmas of the granitoid plutons reflects the chemical variation of basaltic sources (i. e., across-arc chemical variation in the Izu-Bonin arc), as well as a variable contribution of the metasedimentary component in the lower crustal source regions. In addition, the petrogenetic models of the Izu Collision Zone granitoid plutons collectively suggest that the contribution of the metasedimentary component is required to produce granitoid magma with compositions comparable to the average upper continental crust. The Izu Collision Zone plutons provide an exceptional example of the transformation of a juvenile oceanic arc into mature continental crust.

本文言語英語
ページ(範囲)611-629
ページ数19
ジャーナルContributions to Mineralogy and Petrology
163
4
DOI
出版ステータス出版済み - 4 2012
外部発表はい

All Science Journal Classification (ASJC) codes

  • 地球物理学
  • 地球化学および岩石学

フィンガープリント

「Petrogenesis of the Kaikomagatake granitoid pluton in the Izu Collision Zone, central Japan: Implications for transformation of juvenile oceanic arc into mature continental crust」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