用重力三方向小子域滤波解释伊通盆地断裂

Explanation of Faulted Structure in Yitong Basin Using Three-Directional Small Subdomain Filtering

关于伊通盆地的断裂系统,前人主要研究了边界断裂和盆地内的2号断裂的性质.为了精细地解译盆地内其他断裂的基本性质,利用重力场小子域滤波及三方向小子域滤波技术圈定了14条断裂的平面位置,给出了伊通盆地平面断裂构造格架并描述了主要断裂的重力场特征.在与其他地球物理资料(4条地震剖面和4条电阻率断面)的对比分析中,除证实了已有的断裂外,还验证了利用三方向小子域滤波技术最新发现的一些断裂,证明了该方法技术的有效性.阐述了14条断裂的基本性质,重点研究了盆地内中央断裂的存在性和基本性质.指出中央断裂是与盆地东南缘和西北缘两条断裂同期形成的主要控盆构造;2号断裂向西与西拉木伦断裂相连,盆地南部(2号断裂以南)基底与华北板块有关,北部则属于东北微陆块复合基底.

The predecessors mainly researched properties of boundary faults and secondary fault of the faulted system in Yitong basin. In order to explain the characteristics of other faults in this basin, the paper obtains the locations of 14 faults, rebuilds faulted structure pattern curve of this basin and describes the charateristics of gravity field of main faults using the techniques of small subdomain filtering and three-directional small subdomain filtering. The comparison with other physical geography data （4 seismic profiles and 4 electrical resistivity sections） proves that the new found faults by the three-directional small subdomain filtering are existent and ensures that the techniques used in this paper are valid. In the paper, we expatiate on the characteristics of 14 faults and mainly study the existence and property of mid-faults. The mid-faults with boundary faults of this basin are main faulted structure that controls the whole basin and formed in geologic epoch. The secondary faulted structure joints Xilamulun faulted structure and the basal of the south part of this basin （the south of the secondary fault） is related to Huabei plate, while the north of it is compound basal of Dongbei small plates.