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

合作研究：俯冲工厂的地幔输入：评估沿 IBM 收敛边缘和跨 IBM 收敛边缘的空间变化尺度

• 批准号: 0001876
• 负责人: Sherman Bloomer
• 金额: $ 21.35万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0001876&HistoricalAwards=false
• 关键词: Collaborative; Research; Mantle; Inputs; Subduction

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.

该项目的目标是通过对马里亚纳弧南部的岩浆活动进行跨弧研究，查明岛弧火山活动中的地幔成分。研究所建议通过对马里亚纳弧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)弧和弧后的地幔消耗模式是否与地幔在远离弧后扩张轴时的连续熔融一致？2)弧下地幔在10-60公里尺度上的内在不均匀性是什么？3)熔化是如何聚集成弧的？他们将利用一个实地方案回答这些问题，该方案的基础是使用夏威夷MR-1型拖曳车对南海山省从弧到弧后的两个部分进行高分辨率调查;对该省的两个横贯地区进行详细取样（包括熔岩和火山碎屑岩）;通过对取样材料进行岩石学和地球化学鉴定;并通过对资料的解释，确定了沿着轴地幔不均匀性的作用。