辽东湾坳陷古近系残留厚度及基底特征

PALEOGENE RESIDUAL THICKNESS AND BASEMENT FEATURES OF LIAODONG BAY DEPRESSION

以最新的高精度重磁资料为基础,辅以收集的前人地震解释剖面,采用多密度界面同时反演方法,得到了辽东湾坳陷处古近系顶底界面的埋深,在此基础上编制了古近系残留厚度图,并结合收集到的地震解释结果拉取一条剖面,利用重磁联合解释方法对区内基底的构造形态和古近系地层展布特征进行了分析。结果表明:古近系地层在本区内部分缺失,缺失地点主要位于F1断裂西侧的近陆域部分和辽东凸起的构造高点处,其他区域地层厚度分布与构造形态保持一致,即在凹陷处厚而在凸起处薄,整体分布自西向东为"厚-薄-厚-薄-厚"的特点,自SW向NE整体厚度变化不大,辽中凹陷为本区的沉降中心。

In this paper,we calculated the depth of the upper and lower boundaries of the Paleogene for Liao Dong Bay Depression based on the newly acquired gravity data.Residual thickness of the Paleogene and its distribution pattern are analyzed and studied with the results.The research results show that the Paleogene is partly missed on the Liaodong bulge to the west of the fault F1.The data also shows that the residual thickness of the Paleogene is unevenly distributed in different tectonic units,showing apattern of"thick-thin-thick-thin-thick"trend on plane view,while the Liaozhong Sag remains the sedimentation center of this area.