南天山古生代-中生代沉积盆地演化  

Evolution of Sedimentary Basins in South Tianshan during Paleozoic-Mesozoic

作　　者：高小芬[1,2] 林晓[1,2] 徐亚东[1,2] 乐明亮[1,2] 

机构地区：[1]中国地质大学生物地质与环境地质国家重点实验室,湖北武汉430074 [2]中国地质大学地球科学学院,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2014年第8期1119-1128,共10页Earth Science-Journal of China University of Geosciences

基　　金：中国地质调查局项目(No.1212010733802);国家自然科学基金(No.41102070);生物地质与环境地质国家重点实验室自主研究课题(No.GBL11207);中国地质大学优秀青年教师基金(No.CUGL100210)

摘　　要：南天山位于塔里木—卡拉库姆板块和伊犁-哈萨克斯坦板块的碰撞造山带.前人研究表明,该区在古生代经历了洋盆的扩张、俯冲消减和碰撞造山;中生代则进入到陆内发展阶段.但由于该区特殊的地理位置和复杂的构造背景,洋盆的闭合时间及盆地演化的阶段依然存在诸多争论.在广泛收集地质资料的基础上,对我国境内南天山地层大区进行了地层分区,并对每个分区的古生代-中生代盆地沉积序列进行了详细分析,最终划分出5个演化阶段:寒武纪-奥陶纪,南天山洋从有限洋盆发展为成熟洋盆,洋盆性质为弧后盆地;早志留世,南天山洋盆开始俯冲消减,东部红柳河段洋盆在早泥盆世闭合,而西部的俯冲消减则延续至泥盆纪晚期;石炭纪-早二叠世,西部仍存在残余海盆.中二叠世,残余海盆消失,南天山西部碰撞造山,南天山造山带最终形成;中生代,该区进入陆内发展阶段,在三叠纪接受剥蚀夷平;侏罗纪,西部发展成为断陷盆地,东部继续接受剥蚀夷平;白垩纪,西部延续侏罗纪断陷盆地特征,东部则发育成拉分盆地.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.

关 键 词：南天山 古生代 中生代 沉积 构造 盆地演化 

分 类 号：P534[天文地球—古生物学与地层学] P542[天文地球—地质学]