Experiments on Hydrous Intermediate Magmas

含水中质岩浆实验

• 批准号: 0228919
• 负责人: Ian S. Carmichael
• 金额: $ 26.83万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0228919&HistoricalAwards=false
• 关键词: Experiments; Hydrous; Intermediate; Magmas

CarmichaelEAR-0228919Andesitic lava and ash (52-63% SiO2) erupts along the 35,000 km global volcanic arc system, which is associated with the subduction of an oceanic plate at an oceanic trench. This material contains water and represents one of the principal return fluxes of water from the earth's mantle to the crust and to the surface. Thus estimating the concentration of water in intermediate magma is a first order problem, as it not only affects the conditions of melting in the andesite source region, as well as the order and variety of the crystalline phases (as the magmas decompress on ascent), but it also is one of the fundamental controls on explosive volcanism. Moreover constraints on the amount of water in arc related magmas affects the global water budget and the question of whether more water is being subducted in comparison to that released by magmatism. This project will assess the concentration of water in Mexican andesitic magmas over a wide whole composition range, and will provide a thermodynamically based expression for the solubility of water in andesitic magma as a function of pressure, temperature and composition.

CarmichaelEAR-0228919安山岩熔岩和火山灰 (52-63% SiO2) 沿着 35,000 公里的全球火山弧系统喷发，该系统与大洋板块在海沟处的俯冲有关。这种材料含有水，是水从地幔到地壳和地表的主要回流通量之一。因此，估计中间岩浆中的水浓度是一个一阶问题，因为它不仅影响安山岩源区的熔化条件，还影响结晶相的顺序和种类（当岩浆上升时减压时），但这也是控制火山爆发的根本措施之一。此外，对弧相关岩浆中水量的限制会影响全球水预算，以及与岩浆作用释放的水相比是否有更多水被俯冲的问题。该项目将评估墨西哥安山岩浆中整个成分范围内的水浓度，并将提供基于热力学的水在安山岩浆中溶解度与压力、温度和成分的函数关系的表达式。