2003年
Volatile evolution of Satsuma-lwojima volcano: Degassing process and mafic-felsic magma interaction
MELT INCLUSIONS IN VOLCANIC SYSTEMS: METHODS, APPLICATIONS AND PROBLEMS
- ,
- ,
- 巻
- 5
- 号
- 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
- ID情報
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- DOI : 10.1016/S1871-644X(03)80027-X
- Web of Science ID : WOS:000185823100007