Isotopic Studies of Pacific Seamounts and Selected Ridge Segments

海洋地壳岩石研究的一个主要重点是发展上地幔的定量地球化学特征。这些信息对于了解导致海洋地壳形成的来源和过程是很重要的。此外，上地幔的地球化学特征及其均质性/非均质性对地幔对流和地球演化的模型具有重要的约束作用。本奖项的目的是继续研究从太平洋海底山打捞的玄武岩的铅、锶和钕同位素组成。该项目的初步工作在记录东太平洋隆起的海底山和西太平洋“热点”产生的海底山链的岩浆来源方面非常重要。未来两年将支持的工作包括：1)继续分析来自西太平洋的样品，2)开始研究来自夏威夷海脊的样品，以及3)分析来自断裂带附近海山的样品。主要研究人员完全有资格进行拟议的研究。

A primary emphasis in the study of oceanic crustal rocks has been to develop a quantitative geochemical characterization of the upper mantle. Such information is important in understanding both the sources and processes which lead to the formation of the oceanic crust. Additionally, the geochemistry of the upper mantle and its homogeneity/heterogeneity place important constaints on models for convection of the mantle and evolution of the planet earth. The objective of the present award is to continue studies of the lead, strontium, and neodynium isotope composition of basalts dredged from Pacific ocean seamounts. Initial work on this project has been important im documenting the source of magmas to seamounts on the East Pacific Rise and to "hot spot" produced seamount chains in the western Pacific. Work to be supported during the next two years will include: 1)continued analysis of samples from the western Pacific, 2)initiation of studies on samples from the Hawiian Ridge,and 3)analysis of samples from seamounts near fracture zones. The principlal investigators are highly qualified to undertake the proposed study.