Collaborative Proposal: Mantle Inputs to the Subduction Factory: Assessing Scales of Spatial Variability along and across the IBM Convergent Margin

该项目的目标是通过对马里亚纳弧区南部的岩浆活动进行跨弧区研究，确定岛弧火山活动中的地幔成分。投资促进机构建议利用对马里亚纳弧区南部海山省海底火山的实地和实验室研究来回答三个主要问题。1)跨弧和弧后的地幔亏损模式是否与地幔离开弧后扩张轴时的顺序熔融一致？2)10-60公里尺度的弧下地幔固有的不均一性是什么？3)熔体如何聚集在弧内？他们将使用实地方案回答这些问题，该方案以使用夏威夷MR-1拖车对南海山省从弧形到弧后两部分进行高分辨率调查为基础；通过对该省两个横断面(包括熔岩和火山碎屑)的详细采样；通过对采样物质的岩石学和地球化学性质进行表征；以及通过对数据的解释，以确定沿地幔轴线的不均质性的作用。

The objective of the project is to identify the mantle component in island arc volcanism by performing an across-arc study of magmatism in the southern Mariana Arc. The PIs propose to answer three principal questions using a field and laboratory study of submarine volcanoes in the Southern Seamount Province of the Mariana Arc. 1) Is the pattern of mantle depletion across the arc and the back-arc consistent with sequential melting of the mantle as it moves away from the back-arc spreading axis? 2) What is the inherent heterogeneity of the subarc mantle at scales of 10-60 km? 3) How are melts aggregated in arcs? They will answer these questions using a field program based on a high-resolution survey of two portions of the Southern Seamount Province, from the arc to the back-arc, using the Hawaii MR-1 towed vehicle; through detailed sampling of two traverses of the Province (including lavas and volcaniclastics); through characterization of the sampled materials petrographically and geochemically; and through interpretation of the data to identify the roles of along axis mantle heterogeneity.