Collaborative Research: Rare Gases in Samoan Xenoliths

该项目将继续研究萨摩亚热点链中的超镁铁捕虏体。以前的工作已经证明，捕虏体中的稀有气体浓度非常高，其中至少有一些具有高度升高的3He/4He比值(至22RA)和非大气层重稀有气体。继续对萨摩亚各地的捕虏体进行研究，将对仅根据对两个地点的捕虏体的分析得出的暂定结论进行重要的检验。此外，将通过激光聚变对单个晶体进行分析，以表征捕虏体内的小规模惰性气体不均质性。为了更全面地了解稀有气体结果的意义，PI计划研究稀有气体所在的流体包裹体的总化学成分和充填压力。

This project is to continue study of ultramafic xenoliths from the Samoan hotspot chain. Previous work has demonstrated very high noble gas concentrations in the xenoliths, and at least some of them have highly elevated 3He/4He ratios (to 22 RA) and non- atmospheric heavy rare gases. Continued studies of xenoliths from throughout Samoa will provide an important test of the tentative conclusions reached, based on analyses of xenoliths from just two localities. In addition, individual crystals will be analyzed by laser fusion to characterize small-scale noble gas heterogeneity within the xenoliths. To more fully understand the significance of the rare gas results the PIs plan to study the gross chemical composition and the filling pressures of the fluid inclusions in which rare gases reside.