Evolution of Sedimentary Basins in South Tianshan during Paleozoic-Mesozoic
Gao Xiaofen
Lin Xiao
Xu Yadong
Yue Mingliang
Abstract：The South Tianshan is an orogenic belt formed due to the collision of the Tarim plate and Ili-Kazakhstan plate.Previ-ous researches indicate that the South Tianshan evolved from expansion into subduction,and eventually into collision orogenesis in Paleozoic and it entered intracontinental development stage in Mesozoic.Debates about the time of collision and the evolution stages persist because of its special geographic location and complicated tectonic setting.In this paper,some stratigraphic sub-regions are determined according to geological records and sedimentary analysis.The evolution of these Paleozoic-Mesozoic sedi-mentary sequences is divided into the following five stages.As a back-arc basin,it developed from small oceanic basin to mature oceanic basin from Cambrian to Ordovician.The South Tianshan Ocean started subducting.Hongliuhe started closing in Early Silurian,with the eastern part of South Tianshan ocean completely closed in Early Devonian,while the southwest Tianshan continued subducting until the end of Devonian.During Carboniferous and Early Permian,residual basin still existed in the west.It disappeared in Permian and the west of the South Tianshan finally crashed to orogenic belt.In Mesozoic,it developed to intracontinental stage.The whole region has been denuded during Triassic.The western part became fault basins in Jurassic and continued in Cretaceous.The eastern part has been denuded during Jurassic and it developed into pull-apart basins in Creta-ceous.
Keywords：South TianshanPaleozoicMesozoicsedimentologytectonicsbasin evolution
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 1119-1128 )