Collaborative Research: U-Series, Be, Sr, Nd and Pb Isotopic and Trace Element Constraints on Melting and Mass Transfer Processes in Arcs, Philippine Arc System

合作研究：铀系列、铍、锶、钕和铅同位素和微量元素对弧区熔融和质量转移过程的限制EAR-0208095；EAR-0207429；EAR-0207830PI：Asmerom；Morris；Mukasanet物质在地幔和大陆地壳之间的循环主要发生在弧区。然而，许多与弧内熔融和质量传递有关的过程，如熔融和挥发分在从沉积物和蚀变洋壳转移元素中的相对贡献，或者地幔楔体的动力、减压或熔融的相对作用，仍然是个谜。这项合作建议将重点放在吕宋岛，它位于菲律宾弧区构造较简单的部分，以比较可能具有不同地球化学史的两个接近的不同弧区。沉积物贡献的假定差异使拟建地点成为研究质量转移过程及其对地幔融化的可能影响的理想场所。结合U系列和Be同位素数据，结合长寿命的放射性成因和微量元素数据，将对这些岩石进行研究。提出了以下目标：1)利用主、痕量和Nd、Sr、Pb同位素数据，确定四个火山中心(每个弧两个)的熔岩特征，以圈定每个俯冲带的属性；2)确定沉积物成分的性质和组成以及其加入地幔的机制；3)研究弧内动态熔融的作用；以及4)研究U系列核素在岩浆分异过程中的行为。

Collaborative Research: U-Series, Be, Sr, Nd and Pb Isotopic and Trace Element Constraints on Melting and Mass Transfer Processes in Arcs, Philippine Arc SystemEAR-0208095; EAR-0207429; EAR-0207830PIs: Asmerom; Morris; MukasaNet material cycling between the mantle and continental crust occurs primarily in arcs. Many processes related to melting and mass transfer in arcs, such as the relative contributions of melting and devolatilization in transferring elements from sediment and altered oceanic crust or the relative roles of dynamic, decompression or flux melting of the mantle wedge, however, remain enigmatic. This Collaborative proposal will focus on Luzon, located in the tectonically simpler part of the Philippines arc, to compare two different arc settings in close proximity that may have had dissimilar geochemical histories. The presumed difference in sediment contribution makes the proposed site an ideal setting for studying mass transfer processes and their possible effects on mantle melting. Combined U-series and Be isotopic data, in conjunction with long-lived radiogenic and trace element data will be used to study these rocks. The following goals are set forth: 1) to characterize lavas, using major, trace and Nd, Sr and Pb isotopic data, from four volcanic centers, two from each arc in order to delineate attributes of each subduction zone; 2) to determine the nature and composition of the sediment component and the mechanism by which it is added to the mantle; 3) to investigate the role of dynamic melting in arcs; and 4) to investigate the behavior of U-series nuclides during magma differentiation.