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

阿拉斯加州苏厄德半岛基格鲁艾克山脉及附近变质岩的构造环境和隆起历史

• 批准号: 9018922
• 负责人: Elizabeth Miller
• 金额: $ 9.8万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-01-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9018922&HistoricalAwards=false
• 关键词: Tectonic; Setting; Uplift; History; Metamorphic

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.

高温低中压穹隆 以白垩纪花岗岩为核心的变质岩， 高压-低温侏罗系（？）蓝鳍金枪鱼 阿拉斯加的苏厄德半岛。 其成因及构造背景 这些复合体是有争议的，它们的隆起一直是 归因于地壳增厚后的热松弛。 Kigluaik Mts的初步新工作。表明了模式 变形变质和岩浆作用的影响 盆岭新生代变质核杂岩中的 省 野外测绘、构造分析和地质年代学/ 热年代学研究将阐明时间和机制 苏厄德半岛蓝片岩的隆起。 领域 集中研究包括：暴露的最高结构水平; 弱变质的古生代岩石之间的低角度断层， 下为绿片岩至蓝片岩相岩石; 温度核心岩石的圆顶。 这种方法还将 确定隆升是单阶段还是多阶段的。 结果 将影响到时代，区域构造背景， N.阿拉斯加州，并将解决可能的 延伸到下面的近海大陆架区域的历史 白令海和楚科奇海 研究结果还将提供 岩浆作用、变质作用和应变之间的相互作用 地壳中经历巨大垂直隆起的区域。