基于重力异常识别断裂的位错窗口相关法及其在大兴安岭与邻区的应用

Dislocation window correlation method based on gravity anomaly identifying fault and application in Greater Hinggan Mountains and its adjacent areas

断裂的划分及位置的确定对区域地质研究具有重要的作用。通过分析重力的方向导数、小子域滤波等传统划分断裂的方法,提出突出重力线状异常或梯度带拐点的划分断裂、确定断裂位置的位错窗口相关法。结果表明:与方向导数、小子域滤波等方法相比,位错窗口相关法能够有效提高强背景重力异常中断裂线状异常与梯度带的信息;以单一断层模型、剪切断层模型、正常埋深地质体与控凹边界断层模型、较深埋深地质体与控凹边界断层模型验证了位错窗口相关法具有准确识别断裂重力异常信息、确定断裂位置的作用;应用位错窗口相关法能够较好地指示大兴安岭及邻区的德尔布干断裂、大兴安岭莫霍面陡变带、嫩江断裂、孙吴―双辽断裂和赤峰―开源断裂的位置。研究成果为深化大兴安岭与邻区深部地质规律的认识提供了新的依据。

Division and location of faults play an important role in regional geological research.Based on analysis of gravity directional derivative and small domain filtering,a gravity dislocation window correlation method is proposed to classify faults with prominent gravity linear anomalies or inflection points in gradient zones and to determine location of faults.The results show that dislocation window correlation method can effectively improve the information of fracture linear anomaly and gradient belts in strong background gravity anomaly compared with traditional methods such as directional derivative and small domain filtering.Single fault model,shear fault model,normal buried geological body and sag-controlling boundary fault model,deeper buried geological body and sag-controlling boundary fault model verify that dislocation window correlation method can accurately identify gravity anomaly information and determine fault location.The location of Delbugan fault adjacent to Greater Hinggan Mountains and adjacent areas,Moho surface abrupt change zone of Greater Hinggan Mountains,Nenjiang fault,Sunwu-Shuangliao fault and Chifeng-Kaiyuan fault are well indicated by using dislocation window correlation method.The research provides new basis for deepening understanding of deep geological laws in Greater Hinggan Mountains and its adjacent areas.