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

OCE 98-19053 Tucholes推荐的项目是纽芬兰边缘的海洋地球物理场计划，在大西洋最初开放时，纽芬兰边缘与伊比利亚边缘共轭。该项目将提供地球物理现场勘测数据，以支持JOIDES ODP504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，对从已知陆壳到已知洋壳的三个横断面进行地震剖面分析。该项目将与加拿大和丹麦岩石圈中心的科学家共同实施。与来自伊比利亚边缘的其他地球物理和钻探数据一起，它将为测试大陆裂谷、裂解和在“非火山”裂谷环境中启动海底扩张的模型提供关键的数据集。具体地说，它将：1)描述该区域洋壳和陆壳之间过渡地壳的性质；2)提供与伊比利亚边缘的比较，从而能够测试裂谷过程中纯剪切和单剪切的模型；3)确定裂谷过程中侵入和挤压的火成岩物质的数量，提供与其他“火山”裂谷边缘，如东格陵兰边缘的对比数据。

OCE 98-19053TucholkeThe 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.***