Collaborative Research: Primitive Magmatism and Crustal Genesis in an Island Arc

合作研究：岛弧中的原始岩浆作用和地壳成因

• 批准号: 0533226
• 负责人: Peter Kelemen
• 金额: $ 10.15万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-15 至 2007-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0533226&HistoricalAwards=false
• 关键词: Collaborative; Research; Primitive; Magmatism; Crustal

The main goals of this funded project are to test ideas about the origin of continental crust and the basic controls on the volcanic arc output of subduction zones. The western Aleutians contain high Mg# andesites that are very close in chemistry to the average continental crust. This award will support a field program of dredging in the Aleutian arc which is a good natural laboratory because it has never been rifted and shows a gradient of convergence angle from east to west, with strongly oblique convergence in the west. Further, there is a gradient in sediment "flux" along the arc, with the western Aleutians representing a global low-sediment content endmember. The program is aimed at obtaining more volcanic rock samples from the western Aleutian arc in five distinct dredge areas. A 30-35 day multibeam, single channel seismic and sampling cruise (35-40 dredges total) will be undertaken, with bathymetric and SCS surveys prior to sampling. The budget includes costs for a minimal port-cruise program of analyses and 40Ar/39Ar dating of igneous rocks.

该资助项目的主要目标是测试有关大陆地壳起源和俯冲带火山弧输出的基本控制的想法。西阿留申群岛含有高 Mg# 安山岩，其化学成分与普通大陆地壳非常接近。该奖项将支持阿留申岛弧的疏浚现场计划，阿留申岛弧是一个很好的天然实验室，因为它从未发生裂谷，并且显示出从东到西的会聚角梯度，其中西部有强烈的倾斜会聚。此外，沿弧线的沉积物“通量”存在梯度，西阿留申群岛代表全球低沉积物含量端元。该计划旨在从西阿留申岛弧的五个不同疏浚区域获取更多火山岩样本。将进行为期 30-35 天的多波束、单通道地震和采样巡航（总共 35-40 艘挖泥船），并在采样前进行测深和 SCS 调查。预算包括最小的港口巡航分析计划和火成岩 40Ar/39Ar 测年的费用。