Controls of the Lower Cretaceous structures on the sedimentary filling and sandstone distribution in southern Tanan depression

Under the controls of tectonic evolution of the Tamuchage Basin, the Tanan depression went through three sedimentary evolutionary sequences during the Early Cretaceous, including the alluvial to littoral-shallow lake basin sequences during the early stage of rift faulting, bathyal-abyssal lake basin sequences during the climax of rift faulting, and delta-lake basin sequences during the fault depression stage. Five secondary tectonic units have been distinguished for the Tanan depression, including eastern steep slope zone, eastern secondary depression, central low uplift, western secondary depression and western ramp zone. The tectonic framework mentioned above has exercised a major control on the distribution of sedimentary facies and sandstone bodies.