二连盆地乌兰花凹陷古地貌恢复及构造发育史研究

利用古地貌恢复原型盆地，对早期古构造、古环境、古水流等盆地特征有较为直观的认识，可为下步油气勘探奠定良好基础。以乌兰花凹陷为例，对二连盆地中生代残留型凹陷的构造特征开展分析，将地球物理法、残余厚度法、层序地层学法等多种古地貌恢复方法相互结合，并以三维可视化技术为载体，较真实地反映出凹陷的构造发育史特点。古地貌恢复表明，乌兰花凹陷在早白垩世阿尔善组沉积时期，初具雏形，腾格尔组沉积时期为断陷扩张期；赛汉塔拉组沉积时期湖盆萎缩并且构造反转，整体呈现出早盛晚剥的特点。

Study on Paleogeomorphic Restoring and Structural Development History of Wulanhua Sag,Erlian Basin

Intuitive understanding of basin characteristics such as early paleostructure, paleoenvironment and paleocurrent could be got based on paleogeomorphy restoring prototype basins, laying solid basis for further oil and gas exploration. Taking Wulanhua sag as an example, this paper analyzed the structural characteristics of Mesozoic residual sags in Erlian Basin, combined multiple paleogeomorphic restoring methods including the geophysical method, the residual thickness method, and sequence stratigraphic method, used 3D visualization technique as a medium, and truly reflected the structural development history characteristics of the sag. Paleogeomorphic restoring shows that Wulanhua sag took shape during the sedimentary stage of Early Cretaceous Aershan Formation; the sedimentary stage of Tenggeer Formation is the expansion stage of fault depression; lacustrine basin shrank and structure reversed during the sedimentary stage of Saihantala Formation, which as a whole exhibited the characteristics that source rocks were thick at early stage and eroded at late stage.