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Petit-spot geology reveals melts in upper-most asthenosphere dragged by lithosphere
https://nied-repo.bosai.go.jp/records/4270
https://nied-repo.bosai.go.jp/records/4270a371c3ea-3978-425b-be25-919655521a53
| Item type | researchmap(1) | |||||||||||||||||
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| 公開日 | 2023-03-30 | |||||||||||||||||
| タイトル | ||||||||||||||||||
| 言語 | en | |||||||||||||||||
| タイトル | Petit-spot geology reveals melts in upper-most asthenosphere dragged by lithosphere | |||||||||||||||||
| 言語 | ||||||||||||||||||
| 言語 | eng | |||||||||||||||||
| 著者 |
Shiki Machida
× Shiki Machida
× Naoto Hirano
× Hirochika Sumino
× Takafumi Hirata
× Shigekazu Yoneda
× Yasuhiro Kato
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| 抄録 | ||||||||||||||||||
| 内容記述タイプ | Other | |||||||||||||||||
| 内容記述 | Petit-spot volcanism is a phenomenon ubiquitous on Earth. It originates from melt in the uppermost mantle asthenosphere, occurring where the plate flexes and fractures before subduction. Recent geochemical and petrological studies of petit-spot volcanism lava have shown that understanding this form of volcanism can contribute to the investigation of mantle dynamics and CO2 degassing of Earth. However, geological information constraining the magma source of petit-spot remains limited. Here, we present a comprehensive dataset of geochemistry (major and trace elements, and Sr and Nd isotopic compositions) and Ar-40/Ar-39 ages of alkaline basaltic rocks and glasses to define the geological characteristics of petit-spot volcanoes in the northwestern Pacific. The geochemical and geochronological variations of the basalts indicate that petit-spot volcanism is characterized by a petrogenetically and temporally isolated magma system for each volcano. The basalt geochemistry further indicates that the magmas at the volcanoes were derived from the melting of a heterogeneous regional-scale source under a range of conditions. In addition, slight temporal intra-field migration of petit-spot vent fields against the plate motion was detected. These features indicate that the magma originates from isolated melt ponds at the lithosphere-asthenosphere boundary, and that the speed at which the melt ponds are dragged by the plate is only slightly slower than that of the plate motion. Our results provide detailed insight into eruption processes of asthenosphere melts induced by plate-flexure, and also suggest the complete coupling of the lithosphere to the upper-most asthenosphere in the case of large plate subduction. (C) 2015 Elsevier B.V. All rights reserved. | |||||||||||||||||
| 言語 | en | |||||||||||||||||
| 書誌情報 |
en : EARTH AND PLANETARY SCIENCE LETTERS 巻 426, p. 267-279 |
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| 出版者 | ||||||||||||||||||
| 言語 | en | |||||||||||||||||
| 出版者 | ELSEVIER SCIENCE BV | |||||||||||||||||
| ISSN | ||||||||||||||||||
| 収録物識別子タイプ | EISSN | |||||||||||||||||
| 収録物識別子 | 1385-013X | |||||||||||||||||
| DOI | ||||||||||||||||||
| 関連識別子 | 10.1016/j.epsl.2015.06.018 | |||||||||||||||||
