Distribution of the Cretaceous strata in the piedmont area of the Western Kunlun Mountains, Xinjiang

The Cretaceous strata occur as the most important hydrocarbon reservoirs in the piedmont area of the Western Kunlun Mountains, Xinjiang. The Lower Cretaceous strata consist of alluvial fan-braided stream red conglomerates and sandstones intercalated with mudstones. The Upper Cretaceous strata in the Yengisar Group are composed of marine carbonate rocks. These Cretaceous strata occur in the maximum thickness in the Kashi depression, and become progressively thiner and even pinching out westwards, eastwards and northwards. The seismic facies analysis is presented in the present paper for the first time to trace and correlate stratigraphic horizons, and delineate the extent of the Cretaceous strata. The seismic facies may well mirror the macroscopic features and distribution of the Cretaceous strata, and thus have realistic implications for the hydrocarbon exploration in the study area.