额尔齐斯-西拉木伦对接带古生代沉积盆地演化

Paleozoic Sedimentary Basins Evolution of Ertix-Xar Moron Suture

额尔齐斯-西拉木伦对接带位于西伯利亚板块、华北陆块和准噶尔地块之间，其构造演化和古亚洲洋洋盆的打开与关闭有密切的关系。笔者在系统分析研究区3个二级和19个三级构造单元古生代岩石地层、生物地层及年代地层的基础上，对沉积盆地进行原型恢复，共划分出10个盆地类型。同时，根据沉积盆地充填序列对研究区的构造-沉积演化做出了初步的论述。（1）早古生代-早石炭世古亚洲洋俯冲阶段；（2）早、晚石炭世之交的碰撞演化阶段；（3）晚石炭世-早二叠世碰撞及碰撞后演化阶段。研究认为古亚洲洋的闭合由西向东呈“剪刀式”，时间分别为早石炭世末（318 Ma）和中二叠世-早三叠世（260-245 Ma）。三叠纪古亚洲洋消亡总体转为陆相环境。

The Ertix-Xar Moron suture is located at the joint part of Siberia,North China and Junggar,and its tectonic evolu-tion has a close relationship with the opening and closing of Paleo-Asian Ocean basin.In this paper,plates the sedimentary basin types are reconstruted and define 10 basin types by an integrated research on the Paleozoic lithostratigraphy,biostratigraphy and chronostratigraphy are defined.The structure-sedimentary evolution of the study area is discussed based on the sedimentary basin-fill sequence and concluded as the following stages：（1）Early Paleozoic-Early Carboniferous subduction stage of the Pa-leo-Asian Ocean;（2）Early,Late Carboniferous collisional stage;（3）Late Carboniferous-Early Permian collision and post-col-lisional evolution stage.It is suggested that the Paleo-Asian Ocean closed from west to east like “scissors”,and the closing be-gan from the end of the Early Carboniferous （318 Ma）to the Middle Permian-Early Triassic （260-245 Ma）.During Triassic, the Paleo-Asian Ocean disappeared and converted to total terrestrial environment.