Tectonic framework and paleogeographic evolution of the Tarim basin during the Paleozoic major evolutionary stages
Tectonic framework and paleogeographic evolution of the Tarim basin during the Paleozoic major evolutionary stages
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作者：
Lin Chang
塔里木盆地在古生代经历了中晚奥陶世末-早奥陶世、晚奥陶世末、中泥盆世末-早石炭世等几个主要演化阶段，形成了一系列重要的不整合面，中晚奥陶世末-早奥陶世早期的构造运动导致了巴楚古斜坡、塔中隆起与和田河隆起、北方相对沉降坳陷带和唐古孜巴斯坳陷是挤压挠曲沉降的产物，塔中隆起带在晚奥陶世受古隆起的制约，形成向东变窄的半岛状碳酸盐岩台地，马加尔坳陷形成于震旦纪，中、晚奥陶世，唐古孜巴斯凹陷接受了数千米深水泥质、浊积岩沉积，奥陶世末，形成了沿着盆地西北缘的塔尔贝古隆起带和沿沿着盆地西南-东南缘的东南古隆起带，由此形成的构造地貌控制了早志留世浅海陆源碎屑盆地向北东延伸的沉积格局，中泥盆世末，盆地经历了强烈的隆升和强烈的剥蚀作用，沿塔北和塔东古隆起形成了沿着大范围的角度不整合面，盆地构造地貌呈现东低西高的变化趋势，研究表明，中晚奥陶世末-早奥陶世早期的变形可能是由北向碰撞和挤压的结果，而北向碰撞和挤压的结果可能是由北向碰撞和挤压的结果。中泥盆世末，塔北隆起的强烈隆升和满加尔坳陷的褶皱隆升可能是南天山洋碰撞的结果。
Tarim basin underwent several major evolutionary stages during the Paleozoic,including the periods at the end of the Middle to early Late Ordovician,the end of the Late Ordovician and the end of the Middle Devonian or Early Carboniferous,and resulted in a series of important unconformities.The tectonic movement occurred in the Middle to the early Late Ordovician led to the development of the central paleo-uplift belt composed of the Bachu paleo-slope,the Tazhong uplift and the Hetianhe uplift,the relatively subsidence Northern depression belt and the Tangguzibasi depression formed due to compressive flexural subsidence.Constrained by the paleo-uplift,the Tazhong uplift belt of the Late Ordovician formed a peninsula-shaped carbonate platform which narrowed eastwards.The Majiaer depression,which generated in Sinian,and the Tangguzibasi depression received several thousand meters of deep water muddy and turbidite deposits during the Middle to Late Ordovician.At the end of the Ordovician,formed the Tarbei paleo-uplift belts along the northwestern basin margin and the Southeastern paleouplift belt along the southwest to southeastern basin margin.The resulted tectonic geomorphology controlled the Early Silurian depositional framework of the neritic terrigenous clastic basin extended northeast-eastwards.At the end of the Middle Devonian,the basin experienced an intense uplifting and suffered strong denudation,and formed an extensive angular unconformity surface along the Tabei and the Tadong paleo-uplifts.The tectonic geomorphology of the basin during this period changed from lower to higher in the east and higher to lower in the west,which made a significant influence on the paleogeographic pattern of the Late Devonian and Early Carboniferous.The study show that the deformation occurred at the end of the Middle to early Late Ordovician might have resulted from the northward collision and extrusion of the North Kunlun orogenics.At the end of the Middle Devonian,the intensively uplifting of the Tabei uplifts and the folding and uplifting of the Manjiaer depression might be attributed to the collision of the southern Tianshan Ocean.