关键词: 白垩系, 沉积古地理, 库车坳陷, 前陆盆地

Abstract:

The distribution patterns of environments and facies in different stages of Cretaceous (Lower Cretaceous) in Kuqa depression are discussed from point of view of depositional palaeogeography in this paper. The division of sequence stratigraphy , the system tracts and sedimentary facies distributions are linked up with the structural environments inside and around the depression. The structural evolution of foreland basin of Kuqa depression in Cretaceous has its phases, which control the characteristics of depositional palaeogeography development in the depression in different stages. The depositional palaeogeographies of Yageliemu stage and early Shushanhe stage have a clear zonation from north to south and show characteristics of accepting the sediments from both the north and south of source areas,having the coarse detritus in the northern abrupt slope of the depression.The most part of Tabei Uplift had subsided under water at the stages of later Shushanhe and Baxigai, and was overlapped by the highstand system tract at Bashenjiqike stage.The major reservoir horizons of the large scale of gas field Kela 2 are located in the facies zone of the braided-delta at the  Bashenjiqike stage, which have a stable and wide distribution called as the “sandy body apron of braided-delta”

Key words: Cretaceous, depositional palaeogeography, Kuqa depression, foreland basin