From Blueschist to Granulite: Metamorphism in a Convergent Orogen, Seward Peninsula, Alaska

PI建议继续对Seward半岛会聚造山带的高P组分和高T组分进行野外工作和岩石学、地球化学和结构研究。侏罗纪-白垩纪增厚的地壳中的热弛豫使一系列蓝片岩连续隆升并暴露于角闪岩和麻粒岩中。计划在Kigluaik山脉进行详细的工作，以调查这一会聚边缘中、下地壳水平的地球动力学演化。将使用温度、气压和地质年代学方法建立P-T-时间路径。将使用相平衡、流体包裹体和稳定同位素来研究流体的作用。将构建简单的热模型来解释增厚地壳的变质作用。

The PI proposes continued field work and petrological, geochemical and structural studies of both high P and high T components of the Seward Peninsula convergent orogen. Thermal relaxation in crust thickened by Jura-Cretaceous has caused uplift and exposure of a continuous sequence of blueschists to amphibolites and granulites. Detailed work is planned in the Kigluaik Mountains to investigate the geodynamic evolution of middle and lower crustal levels in this convergent margin. P-T- time paths will be established using thermobarometric and geochronology methods. The role of fluids will be investigated using phase equilibria, fluid inclusions, and stable isotopes. Simple thermal models will be constructed to explain metamorphism of thickened crust.