塔南凹陷早白垩世构造演化及其对沉积充填和砂体分布的控制

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

塔南凹陷早白垩世经历了断陷初期冲积-滨浅湖盆层序、强烈断陷期半深湖-深湖湖盆层序及断坳期三角洲-湖泊盆型层序的沉积演化序列。受盆地整体格架的控制,凹陷内可划分出5个次级构造单元,各次级构造单元古构造格架决定了沉积相带展布、砂体的发育和分布。

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.