MISC

2003年

Volatile evolution of Satsuma-lwojima volcano: Degassing process and mafic-felsic magma interaction

MELT INCLUSIONS IN VOLCANIC SYSTEMS: METHODS, APPLICATIONS AND PROBLEMS
  • G Saito
  • ,
  • K Kazahaya
  • ,
  • H Shinohara

5
開始ページ
129
終了ページ
146
記述言語
英語
掲載種別
DOI
10.1016/S1871-644X(03)80027-X
出版者・発行元
ELSEVIER SCIENCE BV

Petrological and geochemical studies of volcanic rocks and melt inclusions of Satsuma-Iwojima volcano, Japan, were carried out to investigate the volatile evolution of the magma chamber since its latest caldera-forming eruption. Petrological studies on basalts, rhyolites and mafic inclusions in the rhyolites from post-caldera eruptions suggest there is a stratified magma chamber beneath the volcano, which consists of a lower basaltic layer, upper rhyolitic layer and an episodically-present, thin middle-andesitic layer. Chemical analyses of 30 melt inclusions in plagioclase and pyroxene phenocrysts from the basaltic and rhyolitic eruptions showed large variations in the volatile concentrations (H2O, CO2, S and Cl) of the melts. This suggests the following volatile evolution processes in the magma chamber: 1) a gas-saturated condition due to pressure variation in the rhyolitic magma chamber just before the caldera-forming eruption; 2) low pressure degassing of the rhyolitic magma chamber by magma convection in the conduit during the active degassing period in the post-caldera stage up to the present; and 3) the addition of CO2-rich volatile from the underlying basaltic magma in the stratified magma chamber to the upper gas-undersaturated (degassed) rhyolitic magma.

リンク情報
DOI
https://doi.org/10.1016/S1871-644X(03)80027-X
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000185823100007&DestApp=WOS_CPL
ID情報
  • DOI : 10.1016/S1871-644X(03)80027-X
  • Web of Science ID : WOS:000185823100007

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