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

这一建议涉及与地幔和大气的起源、地幔流动和现今地幔过程的历史、地幔熔融的性质以及地幔热柱与周围地幔的相互作用有关的基本问题。更具体地说，该提议的目标是了解伴随着地幔热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。这一提议的方法是研究挥发性丰度和同位素比率，特别是H、He、Ne、Ar、CO2和H2O。从英国调查人员那里可以获得北纬57度至63度之间的雷克雅内斯海脊的特征良好的疏浚样本。初步的3He/4He和He丰度数据表明，脱气是61度以北的一个重要过程，浅海喷发深度导致大量脱气和低He丰度。有五个单独的假设可以用要收集的数据来检验，其中大多数与发生的内在过程有关，这些过程与羽流和MORB地幔与其他组分的明显两组分混合一起发生。惰性气体数据将通过粉碎、阶梯燃烧和激光探头收集，这是一种新的有前途的方法。

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.