The Flux of Volatiles from Active MARGINS: the Central American Volcanic Arc

在俯冲带中，从俯冲板块的沉积物到弧形岩浆的物质转移已被化学示踪物质识别，如铍和硼。近年来，在理解俯冲带中的元素旋回和这些旋回运行的时间尺度方面取得了重大进展，目的是实现有效边际的元素预算。可获得的大量关于弧岩浆的详细地球化学信息与可用于活动边缘火山挥发排放的非常有限的详细信息形成了鲜明对比。闪锌矿在俯冲带元素转移中起着关键作用。尽管它们很重要，但人们对俯冲带挥发物的最终来源知之甚少。这个项目的目标是对中美洲火山弧沿线3-4座活火山的挥发性排放物的来源和这些挥发物向大气的通量进行详细、系统的研究。P.I.将试图确定二氧化碳、水、氮和惰性气体的来源，以及它们进入大气的通量。中美洲火山弧是世界上进行此类研究的最佳地点之一，因为可以获得大量关于岩浆的地球化学信息，流体贡献量随弧的走向而变化，地壳污染相对较小，受到很好的约束。这项研究是一项针对这3-4座火山的“初步研究”，目的是测试挥发物的来源与通过地球化学法确定的岩浆来源之间是否存在相关性。

0079402FischerIn a subduction zone, the material transfer from sediments of the subducting plate into arc magmas has been identified by chemical tracers, such as Berillium and Boron. In recent years, significant progress has been made towards understanding the element cycles in subduction zones and the time-scales these cycles operate on with the goal of arriving at element budgets of active margins. The vast amount of detailed geochemical information available for arc magmas stands in contrast to the very limited detailed information available for volatile discharges from active margin volcanoes. Volatiltes play a pivotal role in element transfers occurring at subduction zones. Despite their importance, comparatively little is known about the ultimate sources of the volatiles in subduction zones. Even less is known about the volatile budgets of any active subduction zone.The goal of this project is to perform a detailed, systematic study of the sources of volatile discharges and the fluxes of these volatiles to the atmosphere at 3-4 active volcanoes along the Central American Volcanic Arc. The P.I. will attempt to determine the sources of carbon dioxide, water, nitrogen and noble gases and their fluxes to the atmosphere. The Central American Volcanic Arc is one of the best places in the world for such a study because a vast amount of geochemical information on the magmas is available, the amount of fluid contributions is documented to vary along strike of the arc, and crustal contamination is relatively minor and quite well constrained. The study is a "pilot study" targeting these 3-4 volcanoes in order to test whether there is a correlation regarding the sources of volatiles with the sources of the magmas as identified geochemically.***