Metamorphic Gradients and Fluid Flow Associated with Crystalline Overthrusts

与晶体逆冲相关的变质梯度和流体流动

• 批准号: 9117469
• 负责人: Stephen Reynolds
• 金额: $ 12.17万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9117469&HistoricalAwards=false
• 关键词: Metamorphic; Gradients; Fluid; Flow; Associated

Understanding the thermal and fluid flow consequences of thrust faulting is necessary to understanding heat and mass transfer processes in the earth's crust. Many thrust faults preserve an inverted metamorphic gradient in their footwall rocks, but the mechanisms to produce this are poorly understood. This study will constrain the mechanisms of metamorphism and fluid flow associated with prograde inverted metamorphic gradients in supracrustal rocks of the footwall in two ranges in western Arizona. It will also test the hypothesis that fluids released during the prograde metamorphism migrated upwards and caused retrograde metamorphism in the crystalline rocks of the hanging wall. The approach will be an integrated study of structures, petrology, stable isotopes, fluid inclusions and 40Ar/39Ar systematics. The results will constrain the mechanisms that produce inverted metamorphic gradients, and will increase the understanding of heat and mass transfer processes associated with tectonic events.

了解逆冲断层的热和流体流动后果对于了解地壳中的热量和质量传递过程是必要的。许多逆冲断层在其下盘岩石中保留了一种倒转的变质梯度，但产生这种梯度的机制却鲜为人知。这项研究将约束亚利桑那州西部两个山脉下盘表壳岩石中与递进逆变变质梯度有关的变质作用和流体流动的机制。它还将检验这样一种假设，即在进退变质作用期间释放的流体向上迁移，并导致上盘结晶岩的退变作用。该方法将是对构造、岩石学、稳定同位素、流体包裹体和40Ar/39Ar系统学的综合研究。这些结果将限制产生倒转变质梯度的机制，并将增加对与构造事件相关的热和质量转移过程的理解。