摘要
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.
出处
《地球科学(中国地质大学学报)》
EI
CAS
CSCD
北大核心
2014年第8期1099-1118,共20页
Earth Science-Journal of China University of Geosciences
基金
中国地质调查局项目(Nos.1212010733802
12120113012500)