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

9219002迪博尔德这个项目涉及一个试验性的地震剖面，旨在提高对与阿拉斯加东南部和不列颠哥伦比亚省海岸造山带的地体增长相关的大陆增长过程的理解。地震数据将提供与厚皮逆冲、变质和岩浆作用在大陆岩石圈形成中所起作用的模型有关的约束。它们还将限制在相对板块运动从迎面(白垩纪中期)向横流(始新世)的重大转变期间如何适应俯冲和平移的模型，以及这种重新安排如何影响地壳发展。地震结果将指导后续针对这些问题的研究建议的设计。地震剖面将使用一艘海洋考察船部署的声源阵列，该考察船沿着130公里长的峡湾穿过海岸造山带，并沿海岸放置密集分布(3-5公里)的三分量地震记录器，以记录从0到200公里的偏移。该船还将部署一个4公里长的水听器拖缆，用于同时进行MCS(多通道地震)剖面分析。这一独特的实验将经过验证的海洋地震技术与地震记录器的新能力相结合，以确定已知大陆吸积区的中下层地壳结构和物理性质。***

9219002 Diebold 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. ***