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：U系列，Be，Sr，Nd和Pb同位素和微量元素对菲律宾岛弧系统中熔融和质量转移过程的约束条件（PIS-0208095; PIS-0207429; PIS-0207830）：Asmerom; Morris; MukasaNet地幔和大陆地壳之间的物质循环主要发生在岛弧中。然而，许多与弧中的熔融和质量转移有关的过程，例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，或地幔楔的动力学、减压或通量熔融的相对作用，仍然是谜。该合作提案将侧重于吕宋岛，位于菲律宾弧的构造较简单的部分，比较两个不同的弧设置密切接近，可能有不同的地球化学历史。沉积物贡献的假定差异使拟议的网站研究质量转移过程及其对地幔熔融的可能影响的理想设置。结合U系列和Be同位素数据，结合长寿命放射成因和微量元素数据将用于研究这些岩石。 目的是：（1）利用主量、微量和Nd、Sr和Pb同位素数据，对四个火山中心（每个弧两个火山中心）的熔岩进行表征，以确定每个俯冲带的属性;（2）确定沉积物组分的性质和组成及其加入地幔的机制;（3）研究弧中动力熔融的作用;（4）研究岩浆分异过程中铀系核素的行为。

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.