Misc.

Sep, 2002

Timing and trigger of arc volcanism controlled by fluid flushing from subducting slab

Proceedings of the Japan Academy Series B: Physical and Biological Sciences
  • Tetsuya Yokoyama
  • ,
  • Eizo Nakamura
  • ,
  • Katsura Kobayashi
  • ,
  • Takeshi Kuritani

Volume
78
Number
7
First page
190
Last page
195
Language
English
Publishing type
DOI
10.2183/pjab.78.190

We present 238U-230Th-226Ra systematics in lavas from Miyakejima volcano, Izu arc, Japan, together with major element, trace element and Sr-Nd-Pb isotopic compositions, to estimate the timescale of magmatic processes beneath an island arc. 238U-230Th- 226Ra disequilibria observed in Miyakejima lavas with large excesses of 238U and 226Ra to 230Th imply metasomatism of depleted mantle by fluid related processes. Our data reveal that fluid components released from the slab ascend rapidly through the mantle wedge (&gt
50 m/yr), and that individual stages of subaerial volcanism are induced by flushing of different fluid batches to the mantle wedge with a periodicity of 1-13 kyr. This indicates that arc magmatism is controlled by pulsed release of fluid from the slab occurring on such a small timescale, which might be related to the occurrence of earthquakes in the subducting slab.

Link information
DOI
https://doi.org/10.2183/pjab.78.190
ID information
  • DOI : 10.2183/pjab.78.190
  • ISSN : 0386-2208
  • SCOPUS ID : 0036764654

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