松辽盆地是中国东北盆地群的代表性盆地之一。松辽盆地及其邻区的布格重力异常分布特征以北东-北北东向为主，其次为东西向，重力场分区分块特征明显，显示了明显的拼贴构造背景，依据布格重力异常特征对研究区构造单元进行分区，共分成松辽盆地异常区、大兴安岭重力梯级带等5个特征区。利用小波多尺度分解方法对松辽盆地重力场进行分离，选择最佳的分离阶数(4阶)，随后利用对数功率谱确定每阶异常的视深度，提取区域异常，分层研究地壳顶部(D1G)、基底(D2G，D3G)及深部密度界面(A4G)的起伏特征，共圈定基底凹陷14个，并绘制了研究区的Moho面埋深图。地球物理特征揭示了松辽盆地的深部构造，为研究盆地油气勘探及构造演化提供了重要依据。%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 deep structures, which provide an important basis for oil-gas exploration and studying tectonic evolution.
展开▼
