北冰洋楚科奇边缘地的地球物理场与构造格局  

Geophysical field and tectonic framework of the Chukchi Borderland,Arctic Ocean

作　　者：李官保[1,2] 刘晨光[1,2] 华清锋 韩国忠[1,2] 刘保华[2,3] 

机构地区：[1]国家海洋局第一海洋研究所,山东青岛266061 [2]国家海洋局海洋沉积与环境地质重点实验室,山东青岛266061 [3]国家深海基地管理中心,山东青岛266061

出　　处：《海洋学报》2014年第10期69-79,共11页

基　　金：南北极环境综合考察与评估专项课题(CHINARE2013-03-03-02;CHINARE2014-03-03-02)

摘　　要：利用高分辨率水深、重力、地磁和多道反射地震数据,综合分析了楚科奇边缘地及其周边区域的地形地貌和地球物理场特征,划分了区域构造单元。研究表明,楚科奇边缘地不仅是楚科奇大陆架外缘独特的地形单元,也是一个相对独立的构造单元,与周边的加拿大洋盆、阿尔法-门捷列夫大火山岩省、北楚科奇陆架盆地和阿拉斯加被动陆缘等构造单元在地球物理场和区域构造上具有截然不同的特征。楚科奇边缘地是一个地壳减薄的微陆块,新生代早、中期发生了大规模的E-W向构造拉伸作用,基底断块的差异性升降塑造了当前的地形地貌和沉积层的发育。边缘地可能形成于北楚科奇盆地侏罗纪-早白垩纪的张裂作用,而内部盆-脊相间排列的构造格局则可能与加拿大海盆相边缘地俯冲作用停止后的均衡调整有关。On the basis of high-resolution bathymetry,gravity,magnetic and multi-channel reflection seismic data,the geomorphology and geophysical characteristic of the Chukchi Borderland and its adjacent area was synthetically analyzed and the tectonic division was made.The results shows that the Chukchi Borderland is a relatively isolated tectonic unit and has different geophysical and structural features from the peripheral units,they are Canada Oceanic Basin,Alpha-Mendeleev Large Igneous Province,North Chukchi Continental Shelf Basin and Alaska Passive Continental Margin.Chukchi Borderland is a micro-continental plate with thinned crust,where a large scale E-W oriented tectonic stretching had happened during the early and middle stage of the Cenozoic.Basement uplifting and subsiding is the controlling factor of the modern geomorphic features and sediments accumulation.The Chukchi microcontinental plate was supposed to result from the rifting process of the North Chukchi Basin in Jurassic to early Cretaceous Period,while its modern tectonic framework with juxtaposition of basins and ridges might be the result of isostatic regulation after the cease of subduction of oceanic crust in Canada Basin to the Borderland.

关 键 词：楚科奇边缘地 地球物理场 构造单元 构造演化 

分 类 号：P738[天文地球—海洋地质]