沱沱河盆地古近纪—新近纪盆地演化及青藏高原隆升的沉积响应  

Basin evolutions of the Tuotuohe River basin and sedimentary response to the uplifting of the Qinghai-Tibet Plateau in the Paleogene-Neogene.

作　　者：刘燕学[1] 侯增谦[1] 王光辉[2] 江小均[1] 李政[3] 宋玉财[1] 王晓虎[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]中国地质调查局西安地质调查中心,陕西西安710054 [3]国土资源部信息中心,北京100812

出　　处：《地学前缘》2011年第4期65-76,共12页Earth Science Frontiers

基　　金：国家科技支撑项目(2006BAB01A08);中国地质调查局大地调项目(1212010818096)

摘　　要：通过对青藏高原腹地沱沱河盆地古近纪—新近纪沉积序列、区域不整合面、岩性特点及分布特征等分析研究,认为沱沱河盆地古近纪—新近纪沉积由下而上可分为沱沱河组、雅西措组、五道梁组和曲果组4个向上变浅序列,构成两个完整的陆相造山磨拉石建造序列。盆地分析表明,古近纪—新近纪沱沱河盆地经历了前陆盆地演化阶段(56.5～45.0 Ma)→走滑拉分盆地阶段(45～30.0 Ma)→整体抬升,山间残留盆地阶段(23.5～16.0 Ma)→前陆盆地-局限盆地-山间残留盆地阶段(16～3.6 Ma)→前陆盆地(3.6～2.6?Ma)等阶段。结合青藏高原北部新生代盆地发育过程,提出印度板块与欧亚板块初始碰撞这一地质事件发生在白垩纪与古近纪之交,时间在56.5 Ma之前;其碰撞过程大致可分为3期:初始碰撞期(>56.5 Ma),主碰撞期(56.5～45.0 Ma),脉动型陆内汇聚期(45～2.6 Ma),其中重要的构造转换期在45.0 Ma左右;古近纪—新近纪青藏高原的隆升是分阶段完成的,大致分>56.5～45 Ma、30～16 Ma、16～3.6 Ma、3.6～2.6?Ma 4个隆升阶段。其中30～16.0 Ma的不间断抬升造成羌塘地块已经隆升到相当的高度。On the basis of sedimentary sequences,regional unconformities,lithological associations and distributions of the Paleogene and the Neogene in the Tuotuohe River Basin on the Qinghai-Tibet Plateau,four shallowing-upward sequences consisting of,in an ascender order,the Tuotuohe Formation,Yaxicuo Formation,Wudaoliang Formation and Quguo Formation were recognized,which furthermore constructed two complete continental orogenic molasses successions.Current research indicates that Tuotuohe River Basin was involved in a successive evolution history,i.e.,foreland basin（56.5-45.0Ma）,strike-slip pull-apart basin（45-30.0 Ma）,uplifted residual basin（23.5-16.0Ma）,foreland basin-restricted basin-residual basin（16-3.6Ma） and foreland basin（3.6-2.6Ma（？））.Combined with the basin evolution in the northern Qinghai-Tibet Plateau during the Cenozoic,this research suggests that an initial collision between the India and the Eurasian plates occurred at the turn of the Cretaceous and the Paleogene before the 56.5Ma,and further underwent three periods,i.e.,the first collision（early than 56.5 Ma）,then main collision（56.5-45.0 Ma） and pulsation intracontinental convergence（45-2.6 Ma） finally.However,45.0 Ma is the most important moment of tectonic transformation.Uplifting of the Qinghai-Tibet Plateau from the Paleogene to the Neogene was achieved in the successional periods.First,early than 56.5-45.0 Ma;second,30-16 Ma;third,16-3.6 Ma;and finally,3.6-2.6（？） Ma.The Qiangtang block had reached a considerable height as a result of sustained uplifting during the period from 30 to 16 Ma.

关 键 词：沱沱河盆地 盆地分析 初始碰撞 构造转换 隆升 

分 类 号：TE121.34[石油与天然气工程—油气勘探]