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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy >
Vol.XXII, No.2 >
Origin of Lateral Variations in 87Sr/86Sr Ratios of Quaternary Volcanic Rocks from the Kurile Arc in Hokkaido, Japan
| Title: | Origin of Lateral Variations in 87Sr/86Sr Ratios of Quaternary Volcanic Rocks from the Kurile Arc in Hokkaido, Japan |
| Authors: | Ikeda, Yasuo Browse this author | | Katsui, Yoshio Browse this author | | Kurasawa, Hajime Browse this author |
| Issue Date: | Aug-1987 |
| Publisher: | 北海道大学 |
| Journal Title: | 北海道大学理学部紀要 |
| Journal Title(alt): | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy |
| Volume: | 22 |
| Issue: | 2 |
| Start Page: | 325 |
| End Page: | 335 |
| Abstract: | 87Sr/86Sr ratios were examined for volcanic rocks from Quaternary volcanoes in the Kurile arc in Hokkaido, Japan. The results show that the ratios decrease immediately away from the volcanic front, then increase in the middle part of the arc, but decrease again toward the back-arc side. The complex lateral variations of the ratios can be ascribed to breakdown of different minerals in the mantic wedge, i.e. amphibole decomposes beneath the volcanic front, whereas phlogopite breaks down beneath the middle part of the arc. Geochemical characters of the rocks from Rishiri volcano, located furthest away from the volcanic front arc quite different from those commonly observed in the trench-arc systems. The characters are similar to those of lavas from Deception island, located in Bransfield Strait formed by bad-arc spreading. This suggests that the Rishiri volcanism is independent of the arc magmatism. |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/36753 |
| Appears in Collections: | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy > Vol.XXII, No.2
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