The He-Ne-Ar-H2O-CO2 isotope and abundance systematics of the Reykjanes Ridge: Constraints on plume-ridge interaction and the degassing history of the Icelandic hotspot

这一建议解决了与地球地幔和大气的起源、地幔流动的历史和现在的地幔过程、地幔融化的性质以及地幔柱与周围地幔的相互作用有关的基本问题。更具体地说，该提案的目标是了解伴随地幔柱与大洋中脊下正常地幔相互作用的混合和地幔流动过程。这个建议的方法是观察挥发性丰度和同位素比率，特别是H、He、Ne、Ar、CO2和H2O。在北纬57度至63度之间的雷克雅内斯山脊，英国调查人员提供了特征良好的疏浚样本。初步的3He/4He和He丰度资料表明，脱气是61°以北的重要过程，浅滩喷发深度导致脱气广泛，He丰度低。有五个单独的假设可以用收集到的数据进行测试，其中大多数与内部过程有关，这些过程与羽流和MORB地幔与其他成分的明显双组分混合相结合。稀有气体数据的采集将采用破碎法、阶梯燃烧法和激光探针法，这是一种很有前途的新方法。

This proposal addressees fundamental questions related to the origin of the earth's mantle and atmosphere, the history of mantle flow and present mantle processes, and the nature of mantle melting and the interaction of mantle plumes with ambient mantle. More specifically, the goals of the proposal are to understand the processes of mixing and mantle flow that accompany the interaction of a mantle plume with the normal mantle below mid-ocean ridges. The approach of this proposal is to look at volatile abundances and isotope ratios, especially H, He, Ne, Ar, and CO2 and H2O. Well-characterized dredged samples are available from UK investigators for the Reykjanes Ridge between 57 and 63 degrees north. Preliminary 3He/4He and He abundance data show that degassing is an important process north of 61 degrees, where shoaling eruption depth results in extensive degassing and low He abundances. There are five individual hypotheses that can be tested with the data to be collected, most having to do with the intrinsic processes that happen in combination with apparent 2-component mixing of plume and MORB mantle seen with other components. The noble gas data will be collected by crushing, stepped combustion and with a laser probe, a new and promising method.