Collaborative Research: Relationship between Ultramafic Rocks and Crustal Sutures in the North American Southwest

合作研究：北美西南部超镁铁质岩石与地壳缝合线之间的关系

• 批准号: 0003477
• 负责人: Karl Karlstrom
• 金额: $ 2.18万
• 依托单位: University of New Mexico
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-01-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003477&HistoricalAwards=false
• 关键词: Collaborative; Research; Relationship; between; Ultramafic

0003477Karlstrom0003479SeamanMuch of the western United States continental lithosphere was assembled from 1.8 to 1.6 Ga, but the tectonic style of assembly is controversial, in particular the blocks or terranes of different precambrian characteristics may have been juxtaposed primarily by orthogonal and sequential subduction or the major mechanism may have been transpressional translation. This project will examine the geochemistry in detail of occurrences of ultramafic rocks that seem to spatially be associated with boundaries of precambrian blocks, thus suggesting subduction. A sea-floor ophiolitic geochemical signature would considerably strengthen this option whereas absence would point to alternatives including strike-slip assembly. Results are expected to influence understanding on how the continental lithosphere of much of the western United States was assembled.

0003477Karlstrom0003479Seaman美国西部大陆岩石圈的大部分是在1.8至1.6 Ga期间组装的，但是组装的构造方式是有争议的，特别是具有不同前寒武纪特征的块体或地体可能主要通过正交和顺序俯冲并置，或者主要机制可能是均已进行压压翻译。 该项目将详细研究超镁铁质岩石的地球化学特征，这些岩石似乎在空间上与前寒武纪块体的边界相关，从而表明俯冲作用。 海底蛇绿岩地球化学特征将大大加强这一选择，而缺乏则表明包括走滑组装在内的替代方案。 预计结果将影响对美国西部大部分地区大陆岩石圈如何聚集的理解。