中上扬子印支运动的地层学效应及晚三叠世沉积盆地格局  

Stratigraphic impact of the Indo-China Movement and its related evolution of sedimentary-basin pattern of the late Triassic in the middle-upper Yangtze Region,South China

作　　者：梅冥相[1] 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《地学前缘》2010年第4期99-111,共13页Earth Science Frontiers

基　　金：中国石油化工股份有限公司海相前瞻性项目"中国南方中上扬子大陆构造与海相油气前景"(YPH08009)

摘　　要：发生在晚三叠世的印支运动,结束了中上扬子地区自伊迪卡拉纪以来以一个稳定的古地理单元、而且多数时间沉积浅水碳酸盐岩的漫长的地质历史。该地质事件受控于秦岭造山带的大规模造山隆升和华北板块的向南强烈挤压,并在华夏地块的北西向挤压,以及印支板块的向北挤压的共同作用下,在习称的"扬子地台"的相对较为稳定的基底上于晚三叠世形成一个从残留海相盆地到具有前陆性质的陆相磨拉石盆地的演变序列;而且,这个特别的盆地演变序列与松潘—甘孜地块上发育的晚三叠世前陆浊积盆地的形成和消亡过程存在时间上的对应性。因此,对中上扬子区印支运动的地层学效应以及由此而产生的沉积盆地格局演变的系统描述,为窥视古特提斯洋消亡过程提供了重要线索,而且为重新审视长期以来作为前陆盆地典型代表的、由龙门山造山带的造山隆升所形成的"四川盆地西部前陆盆地"假象提供了一个思考的途径。The Indo-China movement occurred in the late Triassic led to the end of the Yangtze Platform that is characterized by a stable palaeogeographic element from the Edicaran to the end of the middle Triassic with deposition of shallow-water carbonates during much of this time. This geological event was genetically controlled by the extensively orogenic uplift and the strong southward crumpling of the North-China Plate. Together with the action of both the northward crumpling of the Indo-China Plate and the northwestward crumpling of the Huaxia Massif,a particular evolutionary succession of sedimentary basins from the residual marine basin to the continental molasse basin with the nature of the foreland basin was formed on the relatively stable base that is marked by the ＂Yangtze Platform＂. Further,there was a parallelism in time between this particular succession of sedimentary basins and the forming and ending process of the foreland turbidity basin in the late Triassic on the Ruoergai Massif before the middle Triassic in the western part of Sichuan Province. Therefore,a systematic description on the stratigraphic impact of the Indo-China Movement and the evolutionary pattern of sedimentary basins of the late Triassic in the middle-upper Yangtze Region can provide an important clue to peek the death of the Palaeo-Tethyan Sea,and also provide a thinking approach to resurvey a pseudomorph of the ＂Chuanxi Foreland Basin＂ that was genetically formed by the orogenic uplift of the Longmen Mountains orogenic belt,because the ＂Chuanxi Foreland Basin＂ has been used as the typical representation of the foreland basin for a long time.

关 键 词：地层学效应 沉积盆地格局演变 印支运动 晚三叠世 中上扬子区 

分 类 号：P534[天文地球—古生物学与地层学]