Distribution and Origin of Gas and Volatiles in Bishop Rhyolitic Magma

主教流纹质岩浆中气体和挥发物的分布与来源

• 批准号: 9118281
• 负责人: Alfred Anderson
• 金额: $ 23.06万
• 依托单位: University of Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-15 至 1996-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9118281&HistoricalAwards=false
• 关键词: Distribution; Origin; Gas; Volatiles; Bishop

This is for continuation of a project to determine the preeruptive distribution of gas in a large body of rhyolitic magma, the Bishop Tuff. First results of the PI's studies of melt inclusions and of pumice formation pressure and vesicularity suggest that a surprisingly large excess of gas was present in preerupted Bishop magma. To definitely establish the amount of gas in the Bishop magma the PIs plan comprehensive studies of individual pumice clasts from a selected set of old and new stratigraphically controlled sites. They will determine the vesicle and crystal content of individual clasts of pumice as well as the compositions of phenocrysts and the concentrations of H2O, CO2, Cl, Ba, U, Rb and other elements in both enclosed and hourglass melt inclusions in quartz and feldspar phenocrysts. The work will result in the first determination of the distribution of gas in a preeruptive body of magma. This data will then be used to test theories on gas accumulation in magma bodies and its effect on the nature of volcanic eruptions.

这是为了继续一个项目，以确定喷发前 气体分布在流纹岩岩浆的大身体，主教 塔夫 PI对熔体包裹体和熔体包裹体研究的第一批结果 浮岩形成压力和泡状结构表明， 令人惊讶的是，爆发前的毕晓普火山存在大量过量的气体， 岩浆 确定主教体内的气体量 岩浆研究所计划对单个浮石进行全面研究 从地层学上来说， 控制网站。 他们将决定囊泡和晶体 浮岩碎屑的含量和组成 斑晶中H_2O、CO_2、Cl、Ba、U、Rb的含量 以及封闭和沙漏状熔体包裹体中的其他元素 在石英和长石斑晶中。 这项工作将导致 首次确定喷发前的气体分布 岩浆体 这些数据将被用来测试气体理论 岩浆体的聚集及其对岩浆性质的影响 火山爆发