Trans-Hudson造山带西缘古元古代变质深熔作用和演化研究

本项目拟在国际合作填图的基础上，基于详细的野外调查和构造变形研究，利用变质相平衡定量研究的方法，结合详细的岩石学、地球化学及同位素年代学结果，系统研究加拿大萨省Trans-Hudson造山带西缘古元古代变质作用演化与泥质变质岩深熔作用的相平衡关系。阐明变质沉积岩等的相平衡关系与P-T-t轨迹；定量模拟泥质变质岩中熔体形成、分馏和结晶作用及其对变质矿物组合演化的影响，确定深熔作用时代；阐明高级变质过程中锆石和独居石与熔体相互作用行为及其记录的变质深熔作用年龄的地质意义。为探讨Trans-Hudson造山带西缘的构造演化过程和机制提供确凿的变质作用证据，并与我国典型古元古代造山带演化开展对比研究，探讨Columbia超大陆聚合演化机制和动力学背景。

On the basis of detail bedrock mapping, using the quantitative approach of metamorphic phase equilibria, we will systematically study the phase relations of the metamorphism and partial melting of the west margin in Trans-Hudson Orogen, northeastern Saskatchewan, to elucidate P-T-t paths for the metapelites and other metamorphic rocks, and to present more reasonable interpretation for zircon U-Pb age data. Especially, we will quantitatively simulate the formation, fractionation and crystallization of melts derived from metapelites, to measure their formation ages. These studies will be significant for discussing the process and dynamic mechanism of the west margin in Trans-Hudson Orogen, to provide more information for convergence of Columbia supercontinent.