Pb-Sr-Nd-Ar Isotopic Behavior in Deeply Subducted Crustal Rocks

深俯冲地壳岩石中的 Pb-Sr-Nd-Ar 同位素行为

• 批准号: 9316841
• 负责人: George Tilton
• 金额: --
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-01-15 至 1996-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9316841&HistoricalAwards=false
• 关键词: Pb; Sr; Nd; Ar; Isotopic

9316841 Tilton This project will continue parallel isotopic studies of coesite-bearing metamorphic rocks in the Dora Maira massif, Italian West Alps, and the Dabie Mountains, south central China. Recent work in these continental collision zones indicate that continental crustal material has been subducted to depths of at least 100 km, yet has maintained its original crustal character throughout subduction and exhumation. The PI proposes to conduct isotopic studies in these orogenic belts, which are excellent for delineating rates of processes and time and style of petrogenetic settings. The two main purposes of the project are: (1) to develop better understanding of geochronometric systems in ultra high-pressure rocks by resolving differences in the U- Pb and Ar-Ar systems, contrasting Th and U inheritance in monazite, and testing the applicability of the Sm-Nd system; and (2) to provide age and isotopic evidence for geologic and petrogenetic evolution of the collisional and orogenic belts.

9316841 Tilton本项目将继续对意大利西阿尔卑斯多拉迈拉地块和中国中南部大别山的含硅质变质岩进行平行同位素研究。最近在这些大陆碰撞带的工作表明，大陆地壳物质已经俯冲到至少100公里的深度，但在整个俯冲和挖掘过程中仍保持其原始的地壳特征。PI建议在这些造山带中进行同位素研究，这对于描绘成岩环境的过程速率、时间和样式非常有利。本项目的两个主要目的是：(1)通过解决U- Pb和Ar-Ar系统的差异，对比独居石中Th和U的继承性，以及测试Sm-Nd系统的适用性，更好地了解超高压岩石的地质时系统；(2)为碰撞造山带地质成岩演化提供年龄和同位素证据。