Conduit convection, magma mixing, and melt inclusion trends at persistently degassing volcanoes

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• 作者：Fred Witham
• 关键词：volcano ; degassing ; melt inclusion ; volatiles
• 刊名：Earth and Planetary Science Letters
• 出版年：2011
• 出版时间：3 January 2011
• 年：2011
• 卷：301
• 期：1-2
• 页码：345-352
• 全文大小：743 K

文摘

Magmas progressively exsolve volatiles as they ascend towards the Earth's surface, such that their volatile content is a function of pressure. Water and carbon dioxide concentrations measured in melt inclusions from degassing volcanoes rarely coincide with modelled degassing trends. I show that observed melt inclusion trends can be reproduced through mixing of magmas, either during convection within the volcanic conduit, or within a subterranean magma reservoir. No fluxing gas phase or post-entrapment loss of water need be invoked. A permeable network allowing gas transport is still required to avoid fragmentation of magma at shallow depths.