Tectonic Setting and Uplift History of Metamorphic Rocks, Kigluaik Mountains and Vicinity, Seward Peninusla, Alaska

以白垩纪花岗岩为岩芯的高温-低压-中压变质岩呈穹隆状隆起，两侧为高压-低温侏罗系(？)阿拉斯加苏厄德半岛的蓝片岩。这些杂岩的起源和构造环境存在争议，它们的抬升被归因于地壳增厚后的热弛豫。Kigluaik MTS的初步新工作。指示了与盆山省新生代变质核杂岩相似的变形、变质和岩浆作用模式。野外测绘、构造分析和地质年代学/热年代学研究将阐明苏厄德半岛蓝片岩的抬升时间和机制。集中研究的区域包括：暴露出的最高构造水平；古生代弱变质岩石与下方绿片岩至蓝片岩相之间的低角度断层；以及穹隆的高温核心岩。这一方法还将确定抬升是单一阶段还是多阶段的。这些结果将与北阿拉斯加蓝片岩相岩石的年龄、区域构造背景和抬升有关，并将讨论导致白令海和楚科奇海下的近海陆架区的可能的伸展历史。这一结果还将深入了解地壳中经历较大垂直隆起的区域中岩浆作用、变质作用和应变之间的相互作用。

Dome-shaped uplifts of high temperature-low to medium pressure metamorphic rocks with cores of Cretaceous granite are flanked by high pressure-low temperature Jurassic (?) blueschists in the Seward Peninsula of Alaska. The origin and tectonic setting of these complexes is controversial, and their uplift has been attributed to thermal relaxation following crustal thickening. Preliminary new work in the Kigluaik Mts. indicates patterns of deformation, metamorphism and magmatism that are similar to those in Cenozoic metamorphic core complexes of the Basin and Range province. Field mapping, structural analyses, andgeochronologic/ thermochronolgoic studies will elucidate the timing and mechanism of uplift of the blueschists rocks on Seward Peninsula. Areas of concentrated study include: the highest structural levels exposed; low angle faults between feebly metamorphosed Paleozoic rocks and greenschist to blueschist facies rocks beneath; and the high temperature core rocks of the domes. This approach will also establish whether uplift was single or multi-stage. The results will bear on the age, regional tectonic setting, and uplift of blueschist facies rocks in N. Alaska and will address the possible history of extension leading to the offshore shelf region beneath the Bering and Chukchi Seas. The results will also provide insight on the interplay between magmatism, metamorphism and strain in regions of the crust that undergo large vertical uplift.