Collaborative Research: Crustal Structure and Evolution of the Newfoundland-Iberia Non-Volcanic Rift: A Seismic Study of the Newfoundland Conjugate Margin

OCE 98-15999Holbrooke 推荐的项目是纽芬兰边缘的海洋地球物理现场计划，该项目在大西洋最初开放期间与伊比利亚边缘共轭。该项目将提供地球物理现场调查数据，以支持 JOIDES ODP 提案 504 和 504-Full 2。它将利用 R/V Ewing 的大型调谐气枪阵列和 6 krn 拖缆以及广泛的海底地震仪阵列，对从已知大陆地壳延伸到已知海洋地壳的三个横断面进行地震剖面分析。该计划将与加拿大和丹麦岩石圈中心的科学家联合进行。与伊比利亚边缘的其他地球物理和钻探数据一起，它将为测试“非火山”裂谷环境中大陆裂谷、分裂和海底扩张起始模型提供关键数据集。具体来说，它将： 1）表征该地区海洋地壳和大陆地壳之间过渡区的地壳性质； 2) 提供与伊比利亚边缘的比较，从而允许在裂谷过程中测试纯剪切模型与简单剪切模型； 3) 确定裂谷期间侵入和挤出的火成岩物质的量，提供与其他“火山”裂谷边缘（例如东格陵兰边缘）的比较数据。***

OCE 98-15999HolbrookeThe recommended project is a marine geophysical field program on the Newfoundland margin, which was conjugate to the Iberia margin during the initial opening of the Atlantic ocean. The project will provide geophysical site survey data in support of JOIDES ODP Proposals 504 and 504-Full 2. It will utilize the R/V Ewing's large, tuned airgun array and 6 krn streamer together with an extensive ocean-bottom seismometer array to seismically profile three transects that extend from known continental crust to known oceanic crust. The program will be conducted jointly with Canadian and Danish Lithosphere Centre scientists. Together with other geophysical and drilling data from the Iberian margin, it will provide a critical dataset for testing models of continental rifting, breakup, and initiation of seafloor spreading in a "non-volcanic" rifted environment. Specifically, it will: 1) characterize the nature of the crust transitional between oceanic and continental crust in the region; 2) provide a comparison with the Iberian margin, thereby allowing testing of models of pure-shear vs. simple-shear during rifting; and 3) determine the amount of igneous material intruded and extruded during rifting, providing comparative data with other "volcanic" rifted margins, such as the East Greenland margin.***