2015 Fiscal Year Final Research Report
Geochronological and geochemical study of zircons from rhyolitic rocks of the Setouchi Volcanic Rocks: Testing for the slab melting hypothesis
| Project/Area Number |
25400527
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Geochemistry/Cosmochemistry
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| Research Institution | Tokyo Keizai University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
ORIHASHI Yuji 東京大学, 地震研究所, 助教 (70313046)
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| Project Period (FY) |
2013-04-01 – 2016-03-31
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| Keywords | 西南日本弧 / 瀬戸内火山岩 / マグマ / スラブ融解 / ジルコン / ウラン・鉛年代 |
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| Outline of Final Research Achievements |
U-Pb dating of zircons from near trench igneous rocks of the southwest Japan arc was carried out to constrain the age range of the near trench magmatism occurred in the same period with the spreading of Japan Sea and the clockwise rotation of the southwest Japan arc. Taken together results of this study and previous data, age ranges of the Setouchi Volcanic Rocks in Kii Peninsula, western Shikoku and eastern Kyushu totally overlap, and the change of the age for along arc direction is not observed. In addition, clear arc transverse direction age change, including the Outer Zone Granitic Rocks for western Shikoku and Kii Peninsula is not also observed. Based on the whole rock chemical composition analysis of Setouchi felsic volcanic rocks, dacite - rhyolites with high Sr / Y ratio that might be derived from the slab melting are to have been produced in the range of the central Kii Peninsula and western Shikoku.
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| Free Research Field |
地質学
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