Sedimentary facies characteristics of the Cretaceous in southwestern Tarim Basin

In southwestern Tarim Basin, the Cretaceous was developed well with Upper and Lower. The Lower Cretaceous Kizilsu Group is subdivided into four members. They are dominated by terrestrial sedimentary rocks of brownish red glutenites intercalated with sandstones, silts, mudstones and conglomerates. The Upper Cretaceous Yengisar Group is composed of both marine and non-marine facies and summarized in ascending order. The Kukebai Formation is subdivided into two members and commonly composed of mudstones, gypsum beds and marine fossils. The Wuyitage Formation is characterized of red mudstones and muddy silts intercalated with sandstones. The Yigeziya Formation is rich in limestones, dolomitic limestones and marine fossils. The Tuyiluoke Formation is composed of brownish red mudstones, gypsum beds, sandstones, conglomerates and some marine fossils. The study supplies an evolutionary process of the northwestern Tarim Block during the Cretaceous based on the temporal and spatial distribution of nine units covering t