塔里木盆地三叠纪岩相古地理特征

塔里木盆地三叠纪主要为内陆湖泊的陆相沉积。文中以沉积学理论为指导．以不同地区单井地层．沉积相柱状图解释为基础．对塔里禾盆地三叠系进行了沉积相划分和沉积体系分析，并对沉积相类型、古地理环境及沉积相时空演化进行了系统分析。研究认为：早三叠世，塔里木盆地以湖泊和湖泊三角洲体系沉积为主，库车坳陷北部山前发育冲积扇一扇三角洲沉积体系；中三叠世，库车坳陷沉积格局变化不大，盆地内部湖泊面积有所扩大，塔北地区开始发育湖泊三角洲体系：晚三叠世，由于古特提斯洋持续向塔里木板块俯冲，特提斯南缘的羌塘地块与塔里木板块发生碰撞．受此构造运动影响，盆地内部湖盆开始向北退缩，塔北及库车坳陷开始出现含炭沼泽．盆地沉积演化开始向侏罗纪过渡。

Characteristics of Triassic lithofacies palaeogeography in Tarim Basin

In Triassic, Tarim Basin was a continental basin dominated by inland lake. This paper used the sedimentary theory, divided the Triassic sedimentary facies and analyzed the sedimentary system based on the interpretation result of cohmm diagram of stratum-sedimentary facies in different regions of Tarim Basin. It also systematically analyzed the types of sedimentary facies. paleogeographical envirnnment and the time-space evolution of sedimentary facies. Study suggested that in early Triassic, Tarim Basin was dominated by lake and lake-deha systems and developed alluvial fan and fan-delta systems in the submonntain region of northern Kuche l）epressinn. In middle Triassic, the change of sedimentary framework is not great and the area of lake within the basin expanded. The lake-deha began to develop in Tabei Area. Up to late Triassic, the lake began to shrink to the north because of the collision of Qiangtang massif and Tarim plate in the southern margin of Tethys. Tabei Area anti Kuqa Depression began to appear carbonaceous swamp and the basin had its transition to Jurassic.