中国东部海区岩石层结构的区域综合地球物理研究

结合新一轮编图工作的开展,中国东部海区重、磁平面图件在拼入新资料同时,也包含了邻区朝鲜半岛,台湾岛,日本海,菲律宾海等地区的资料.本文在此基础上综合分析研究区重、磁异常特征,利用重、磁资料反演莫霍面、居里面,进而求取了热岩石层底界面,对重、磁数据进行了突出断裂带信息的处理,确定了13条重要断裂带的展布,将研究区划分为8个块体和4个结合带,它们具有"东西成带、南北分块"的特征,是"2条锋线"作用的产物.研究表明,江—绍断裂带向东延伸进入海区,虽然受东海陆架西缘断裂带的切割,但仍继续往东延伸,可能延至朝鲜半岛南端与济州岛南缘断裂带相接;在朝鲜半岛西缘地球物理场存在NNW—NW的明显界线,可解释为断裂带,称之黄海东缘断裂带,中国大陆东部的五莲—青岛断裂带与黄海东缘断裂带和济州岛南缘断裂带共同构成中朝和扬子块体的边界.

Integrated regional geophysical study on lithospheric structure in eastern China seas and adjacent regions

Using gravity and magnetic data of eastern China seas and adjacent regions, we calculated the Moho discontinuity, Curie boundary and thermal lithosphere interfaces and dealt with some processing of gravity and magnetic data to enhance the fault information. Based on this and the analysis of the characters of gravitaty and magnetic fields, we determined the distribution of major faults in this region, which can be divided into two systems:one is the plate boundary fault system, and the other is the system of block boundary faults and faults within blocks.With the fault systems, we divided the areas of eastern China seas and adjacent regions into eight blocks and four conjunction zones. The results indicate that the boundary in eastern China seas and adjacent regions between the Sino-Korea and Yangtze blocks mainly consists of the Wulian-Qingdao fault in eastern China, the eastern marginal fault of the Yellow Sea, and the south marginal fault of the Cheju island. The Jiang-Shao fault extends to the south tip of the Korea peninsula and serves as the boundary to separate the Yangtze and South China blocks.