A Window Into Deep Lithospheric Processes of the Western U.S. From Os Isotope Investigations of Mantle Xenoliths

从地幔包体的骨同位素研究了解美国西部深部岩石圈过程的窗口

• 批准号: 9909526
• 负责人: Paul Hoffman
• 金额: $ 8.99万
• 依托单位: Harvard 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: 2000-01-01 至 2001-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909526&HistoricalAwards=false
• 关键词: Window; Into; Deep; Lithospheric; Processes

RudnickEAR-9909526We propose to investigate the tectonic processes occurring in the deep lithosphere of the SW US through studies of mantle xenoliths erupted along an E-W transect from the Sierra Nevada to the Colorado Plateau. Petrography, mineral and major element chemistry, thermobarometry and Re-Os isotopic compositions will be determined for several suites of mantle xenoliths from the Sierra Nevada mountains (Big Creek and Oak Creek), the Basin and Range (Cima volcanic field) and the Colorado Plateau (the Thumb). This traverse samples Proterozoic crust that has been subjected to diverse tectonic influences: arc magmatism (Sierra Nevada), compressional tectonism (Colorado Plateau) and back-arc extension (basin and range). The goal is to map the lithospheric mantle in these diverse regions in order to determine the present day thickness and age of the lithosphere. These data will then be integrated with surface geology and geophysical remote sensing of lithospheric structure to infer the processes that have shaped the deep lithosphere.

我们建议通过研究从内华达州到科罗拉多高原沿沿着东西向断面喷发的地幔捕虏体来研究发生在美国西南部岩石圈深部的构造过程。将对来自Sierra内华达州山脉（Big Creek和橡树溪）、盆地和山脉（Cima火山场）和科罗拉多高原（The Thumb）的几套地幔捕虏体进行岩相学、矿物和主要元素化学、热压法和Re-Os同位素组成的测定。这条横贯线对受到不同构造影响的元古代地壳进行了取样：弧岩浆作用（内华达州山脉）、挤压构造作用（科罗拉多高原）和弧后伸展作用（盆地和山脉）。 目的是绘制这些不同地区的岩石圈地幔图，以确定岩石圈的现今厚度和年龄。 然后将这些数据与岩石圈结构的地表地质和地球物理遥感相结合，以推断形成深层岩石圈的过程。