Continental and Convergent-Margin Volcanism: Isotopic Studies of Fluids and Rocks

这笔赠款将继续支持从热点地区的火山中心以及沿会聚的板块边缘和大陆裂谷对稀有气体和其他稀有气体的同位素进行研究。主要的重点是~3He作为地幔挥发分的“原始”示踪剂，以及它与甲烷的联系以及甲烷和二氧化碳中碳的同位素组成。火山熔岩中的~3He具有宇宙成因性质，在侵蚀研究中作为示踪剂的作用已得到证实。与大洋中脊玄武岩相比，在八个太平洋热点地体中发现了高的3He/4He比值，这清楚地证明了上升的羽流从较少枯竭的地幔输送气体。使用稀有气体解决地幔化学和动力学问题的这些研究和类似类型的研究将在PIS的监督下继续进行。这项奖励将对已经收集的许多样本进行分析，并将支持国际和平研究所的实验室再运行一年

This grant will provide continued support of research on rare gasses, and isotopes of other rare gasses, from volcanic centers over hot spots, and along convergent plate margins and continental rifts. Primary emphasis has been on 3He as a "primordial" tracer for mantle volatiles, and its association with methane and the isotopic composition of carbon in CH4 and CO2. The cosmogenic nature of 3He in volcanic lavas has been recognized and its usefulness as a tracer in erosion studies has been demonstrated. High 3He/4He ratios, relative to Mid-Ocean Ridge Basalts, have been identified in eight Pacific hotspot terrains, clear evidence of transport of gases from the less depleted mantle by rising plumes. These and similar types of research using rare gasses to solve problems of mantle chemistry and dynamics will continue under the PIs supervision. This award will provide for the analysis of many samples already collected, and will support the operation of the PI's lab for another year