Study of Shear Zones and Associated Intrusions, Coastal Orogen, British Columbia and Alaska

剪切带和相关侵入、沿海造山带、不列颠哥伦比亚省和阿拉斯加的研究

• 批准号: 8903885
• 负责人: Maria Crawford
• 金额: $ 9.89万
• 依托单位: Bryn Mawr College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1992-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8903885&HistoricalAwards=false
• 关键词: Study; Shear; Zones; Associated; Intrusions

Mid to deep levels of continental crust are exposed in the collisional orogen of the Coast Crystalline Complex of South- eastern Alaska and adjacent British Columbia. Crustal thicken- ing and metamorphisms as well as later uplift were accomplished by movement of crustal blocks along regional shear zones and accompanied by emplacement of tabular bodies of intrusive igneous rocks. This project aims to determine the timing of shear zone formation relative to metamorphism and igneous intrusion. The deformation mechanisms, amount of shear strain, sense of displacement and the P and T of the deformation will be obtained by a combination of detailed field and microstructural studies, fluid inclusion and isotopic studies. Results will evaluate the role of fluids, magma and hydrothermal, in shear zone initiation, movement and closure and will be of considerable utility in understanding crustal evolution in orogenic zones generally.

大陆地壳的中深层暴露在阿拉斯加东南部和邻近不列颠哥伦比亚省海岸结晶杂岩的碰撞造山带中。 地壳增厚、变质作用以及后来的隆起是通过地壳块体沿着区域剪切带的运动以及伴随着侵入火成岩的板状体的侵位而完成的。 该项目旨在确定剪切带形成相对于变质作用和火成岩侵入的时间。 变形机制、剪切应变量、位移感以及变形的 P 和 T 将通过详细的现场和微观结构研究、流体包裹体和同位素研究相结合来获得。 结果将评估流体、岩浆和热液在剪切带起始、运动和闭合中的作用，并且对于理解造山带的地壳演化具有相当大的实用性。