Collaborative Research: Rare Gases in Samoan Xenoliths

本项目将继续研究来自萨摩亚热点链的超镁铁质捕虏体。先前的研究表明，捕虏体中稀有气体的浓度非常高，至少其中一些捕虏体具有很高的3He/4He比率（至22ra）和非大气重稀有气体。继续对萨摩亚各地的捕虏体进行研究，将为根据对仅两个地点的捕虏体进行分析而得出的初步结论提供重要的检验。此外，将对单个晶体进行激光聚变分析，以表征捕虏体内小尺度稀有气体的非均质性。为了更充分地了解稀有气体结果的意义，PIs计划研究稀有气体所在的流体包裹体的总化学成分和填充压力。

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.