银根—额济纳旗盆地下白垩统银根组的确立

THE LOWER CRETACEOUS YINGEN FORMATION IN THE YINGEN—EJINAQI BASIN

银根—额济纳旗盆地是中国西部的一个中新生代沉积盆地,盆地地层有多种不同的划分。近几年来,盆地经历了详细的石油勘探和地质调查。在地震和钻井勘探过程中,于下白垩统发现了一套新的地层单元,这套地层的古生物、电性、岩性、物理特征及地震层序与上覆和下伏地层有很大差别。这套新地层位于下白垩统上部,定名为银根组(K1y),银根组中部有良好储层,上部泥岩可作为区域性盖层,与下部烃源岩构成良好的生储盖组合,有一定的勘探意义。

The Yingen-Ejinaqi Basin is a Mesozoic-Cenozoic sedimentary basin in northwestern China. The stratigraphy of the Yingen-Ejinaqi Basin is poorly understood. In recent years, petroleum exploration and geological investigation in the basin has resulted in a better understanding of the stratigraphy in this basin. On the basis of seismic and drill core data, a new lithostratigraphic unit of Lower Cretaceous age is recognized. The paleontological, lithological, electrical and physical properties, and seismic characteristics of this unit are distinct from the overlying and underlying strata. This new unit is named as the Yingen Formation （K1y） and is considered late Early Cretaceous in age. The implications of this new stratigraphic unit for oil exploration in the Yingen-Ejinaqi Basin are also discussed.