中国东北地区重力场研究——利用改进的三方向小子域滤波划分主构造线及大地构造单元  

Study of gravity field in Northeastern China area:Classification of main structure lines and tectonic units using the improved three-directional small subdomain filtering

作　　者：张凤旭[1] 张兴洲[2] 张凤琴[3] 孟令顺[1] 薛进[4] 

机构地区：[1]吉林大学地球探测科学与技术学院,长春130026 [2]吉林大学地球科学学院,长春130026 [3]吉林大学物理学院,长春130023 [4]江苏省工程物理勘察院,南京210008

出　　处：《地球物理学报》2010年第6期1475-1485,共11页Chinese Journal of Geophysics

基　　金：国家重点基金项目(40739905);国家油气选区项目(14B09XQ1201)联合资助

摘　　要：利用重力异常进行大地构造单元的划分是区域重力资料处理与解释的重要任务.为了精细地划分中国东北地区大地构造单元及其分界线位置,对三方向小子域滤波进行了改进,探讨了改进的三方向小子域滤波的合理性.利用小子域及改进的三方向小子域滤波对研究区布格重力异常进行处理,并与欧拉反褶积反演结果进行对比分析.结果表明,改进的三方向小子域滤波在识别平面断裂的应用中具有更好的效果.综合分析东北地区布格重力异常特征、小子域和改进的三方向小子域滤波结果,划分出延续性较好、规模较大的断裂18条.对研究区重力异常进行了分区,描述了一、二级异常的分区特点,给出了东北地区大地构造单元的基本格架.黑河齐齐哈尔—白城等重要构造线平面位置的确定突破了传统的重力异常分区模式,指出东北地区NE向构造具有走滑特征,且走滑距离具有由西向东逐渐增大的特点.Classification of main structure lines and tectonic units is an important mission in regional geophysical data processing and explanation. In order to divide tectonic units and delinrate positions of main structure lines, we modified the method of three-directional small subdomain filtering and discussed the rationality of the improved method. We processed the data of Bouguer gravity anomalies in Northeast China using the method of small subdomain filtering, the modified technique, and Euler deconvolution, and analyzed the effect of filter among them. It is shown that the improved three-directional small subdomain filtering can identify more information for planar location of faulted structures. According to the characteristics of Bouguer gravity and based on the results of the small subdomain and improved three-directional small subdomain filtering in Northeastern China area, 18 faults were identified. The paper divides the Bouguer gravity into first-order and secondary anomaly regions and describes the characterristics of their gravity fields and depicts the framework of tectonic units in Northeast China area. The determination of planimetric positions of main structure lines breaks through the conventional partition model of gravity field and reveals the movement relations among the structure lines. It is shown that the NE-striking structural zones are strike-slip faults and their distance is gradually increasing from west to east.

关 键 词：重力场 改进的三方向小子域滤波 欧拉反褶积 大地构造单元 走滑距离 

分 类 号：P631[天文地球—地质矿产勘探] P312[天文地球—地质学]