阿南凹陷早白垩世网状河湿地的发现

Discovery of Early Cretaceous Anastomosing River Wetlands in Anan Depression

通过对数百米岩心的系统观察,结合多项分析化验资料,本文揭示了在内蒙古二连盆地阿南凹陷阿尔善组(K1)发现了河流湿地沉积。这是我国中新生代陆相含油气盆地首次在白垩系地层中发现的湿地沉积。湿地面积约300km^2,九期累计厚度约100m,每期均由具有统一水动力系统的四个地貌单元构成,即网状河、沼泽、湖泊及草甸,它们各有其岩性和生物化石特征。

Through systematic description of hundreds of meters of cores,combined with a number of analytical tests,this paper reveals the extensive development of river wetland deposits in the Alshan Formation(K1)of the Anan Sag,Erlian Basin,Inner Mongolia,which is the first discovery of Cretaceous wetland sedimentation in Mesozoic and Cenozoic continental petroliferous basins.The wetland area was about300 km2,and the total thickness of the nine-stage sediment was about 100 m.Each wetland had four geomorphic units with a unified hydrodynamic system,namely reticulated rivers,swamps,lakes and meadows,each with unique lithology and Biological fossil features.