Generation and Evolution of Shoshonitic Magmas, Northern Mariana and Southern Volcano Arc

该项目将继续研究钾玄质岩浆， 马里亚纳群岛最北端的弧，以测试假设， 是由于交代富集地幔的去顶作用， 这是马里亚纳海槽向北扩展的结果。 本项目的总体目标是更好地了解ARC 岩浆作用 具体而言，目标是确定：（1） 钾玄岩区母岩成分 检查选定火山的代表性熔岩;（2） 富集弧岩浆源区的空间分布 跨岛链海山熔岩分析;（3）时间 钾玄岩的分布--通过研究 残留物和额弧。 %%% 调查人员获得了一套非常不寻常的 火山弧的样本 将进行的分析 在这个项目中，应该解决一些与 弧岩浆作用 其中最重要的是 弧火山的组成和早期演化。 这个问题 是重要的，因为弧在 大陆地壳的形成。

This project will continue work on shoshonitic magmas from northernmost Mariana arc to test hypothesis that the enrichments result from the unroofing of metasomatically enriched mantle as a consequence of the northward propagation of the Mariana Trough. The overall objective of this project is to better understand arc magmatism. In particular, the goals are to determine: (1) the compositions of parental lavas in shoshonitic province--by examining representative lavas from selected volcanoes; (2) the spatial distribution of the source of enriched arc magmatism--by analyses of cross-chain seamount lavas; (3) the temporal distribution of shoshonites--by studying volcanic rocks from remnant and frontal arcs. %%% The investigators have obtained a very unusual suite of samples from a volcanic arc. The analyses that will be carried out in this project should address a number of question related to arc magmatism. The most important of these are the composition and early evolution of arc volcanoes. This question is important because of the possible role of arcs in the formation of continental crust.