Volatile Migration in Silicic Lavas

内生火山碎屑流可能在没有预警的情况下从推进的、相对干燥的硅质熔岩的远端部分出现，这表明挥发分集中。该项目将调查挥发分的迁移过程，并将涉及以下活动：1)模拟硅质熔岩流的冷却，以量化结晶、角砾化和气泡形成过程；2)测量挥发分的分布和同位素特征，并绘制圣海伦斯、桑蒂亚吉托和圣奥古斯丁活动英安岩穹隆中的泡孔结构图；3)通过扫描电子显微镜和形变实验对硅质熔岩中微裂缝的形态和能量进行表征，以评价其在挥发分运移中的可能作用。PI将从事实地收集、在Novarupta圆顶上绘制地图、实验研究和结果综合。

Endogenic pyroclastic flows may emerge without warning from distal portions of advancing, relatively dry silicic lava, suggesting concentration of volatiles. This project will be an investigation of processes by which volatiles migrate, and will involve the following activities: 1) Modeling of the cooling of a silicic lava flow to quantify processes of crystallization, brecciation and vesiculation; 2) measuring distribution and isotopic signatures of volatiles, and mapping vesicular textures in active dacite domes at St. Helens, Santiaguito, and St. Augustine; 3) characterizing the morphology and energetics of microcracis in silicic lavas through SEM and deformation experiments to evaluate the possible role in volatile transport. The PI will be engaged in field collecting, mapping on Novarupta dome, experimental studies, and synthesis of results.