Crustal structure of the Antarctic continental margin in the eastern Weddell Sea
Crustal structure of the Antarctic continental margin in the eastern Weddell Sea
复制标题
威德尔海东部南极大陆边缘的地壳结构
DOI：
--
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Christian Hübscher
中科院分区：
文献类型：
--
作者：
W. Jokat;H. Miller;Christian Hübscher
1990年和1992年，阿尔弗雷德·韦格纳研究所进行了两次海陆地震折射实验，以加深对德龙宁·莫德地外威德尔海东部火山被动边缘地壳结构的认识。测量了四个剖面，两个平行于12°W和4°W之间的边缘，两个垂直于8°W。这些数据是第一次获得的整个地壳离岸德龙宁毛德地地震速度测量。地震剖面的解释揭示了火山被动边缘典型的大陆地壳速度分布。下地壳的速度高达7.5 km s−1，这表明有岩浆侵入或底侵作用。基底被Explora Wedge的火山挤出物覆盖，最大厚度为8公里。地壳向北变薄，从冰缘附近的40公里厚减到不到25公里。由于地壳中的速度分布以及大陆边是在地幔柱之上形成的假设，该大陆边可被视为北大西洋大陆边（东格陵兰和沃伦大陆边）的类似物。
Abstract Two land/sea seismic refraction experiments were carried out by the Alfred Wegener Institute in 1990 and 1992 to increase the understanding of the crustal structure of the volcanic passive margin in the eastern Weddell Sea off Dronning Maud Land. Four profiles were measured, two parallel to the margin between 12°W and 4°W and two perpendicular at 8°W. These data are the first seismic velocity measurements obtained for the entire crust offshore Dronning Maud Land. The interpretations of the seismic sections reveal velocity distributions which are typical of continental crust at volcanic passive margins. The lower crust exhibits velocities up to 7.5 km s−1, which indicates magmatic intrusions or underplating. The basement is overlain by the volcanic extrusions of the Explora Wedge, which has a maximum thickness of 8 km. The crust thins northwards from 40 km thickness near the ice edge to less than 25 km. Because of the velocity distribution in the crust and the assumption that the continental margin was created above a mantle plume, the margin can be regarded as an analogue of the continental margin in the North Atlantic (East Greenland and Vøring Margin).