Collaborative Research: An Integrated Study of Continental Growth at a Convergent to Transpressive Plate Margin

[9219294] Hollister该项目包括一个试验地震剖面，旨在提高对阿拉斯加东南部和不列颠哥伦比亚省海岸造山带与地体增加相关的大陆生长过程的理解。地震资料将为厚皮逆冲作用、变质作用和岩浆作用在大陆岩石圈形成过程中的作用模型提供约束条件。它们还将限制在相对板块运动从正面（白垩纪中期）到横向（始新世）的重大转变期间俯冲和平移是如何适应的模型，以及这种重新排列如何影响地壳发育。地震结果将指导后续研究方案的设计。地震剖面将使用一艘海洋研究船上部署的声源阵列，该船沿着130公里长的峡湾穿过海岸造山带，并沿着海岸放置密集间隔（3-5公里）的3分量地震记录仪，记录0至200公里的偏移量。该船还将部署一个4公里长的水听器拖缆，用于同步MCS（多通道地震）剖面。这个独特的实验结合了成熟的海洋地震技术和地震记录仪的新功能，以确定已知大陆增生区域的中下地壳结构和物理性质。＊＊＊

9219294 Hollister This project involves a pilot seismic profile designed to improve understanding of processes of continental growth associated with terrane accretion in the Coast orogen of southeast Alaska and British Columbia. The seismic data will provide constraints pertaining to models for the role of thick-skinned thrusting, metamorphism and magmatism in the formation of continental lithosphere. They will also constrain models on how subduction and translation were accommodated during a major shift in relative plate motions from head-on (mid Cretaceous) to transcurrent (Eocene), and how this rearrangement affected crustal development. The seismic results will guide design of subsequent research proposals on these problems. The seismic profiling will use an acoustic source array deployed from a marine research ship that crosses the Coast orogen along a 130 km long fjord, and densely spaced (3-5 km) 3-component seismic recorders placed along the shore to record offsets from 0 to 200 km. The ship will also deploy a 4 km long hydrophone streamer for simultaneous MCS (multi-channel seismic) profiling. This unique experiment combines proven marine seismic techniques with the new capability of the seismic recorders to determine mid to lower crustal structure and physical properties of an area of known continental accretion. ***