Interpretations of Bouguer Gravity Anomaly with the Method of Wavelet Multi-scale Decomposition(WMD) in Songliao Basin,Northeast China

The Songliao Basin is one of the typical basins among the NE China Basin Groups. The main structural trending of gravity anomaly field is NNE to NE, and the study area shows a significant feature of deep collage-type pattern. Accordingly, the region is divided into five subregions with different features of gravity anomalies. The gravity field of NE China Songliao Basin is separated,using the WMD method with the 4th separation order, the apparent depth of the anomalies in each order is determined using the Logarithmic PSA. The shallow high-frequency anomalies are then removed to obtain the regional gravity anomalies. Through the hierarchical analyses, we learned the characters of the irregularity of the shallow crust, basement, and the crustal deep interfaces, and identified 14 depressions of the basement while drawing a depth map of Moho discontinuity. The geophysical characteristics of Songliao Basin reveal its deepstructures, which provide an important basis foroil-gas exploration and studying tectonic evolution