【作者】 谭富荣；

【导师】 周立发；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2011， 硕士

【摘要】 南祁连盆地位于祁连山褶皱带的南部,西南邻柴达木盆地,西北被具有左行走滑性质的阿尔金断裂截切,北与中祁连地块相接,东南与西秦岭相连。前人的众多研究主要集中在加里东期、海西期、印支期南北板块碰撞造山的基本模式、造山过程和造山作用,而对海西旋回、印支旋回的原始盆地面貌及其演化过程研究甚少。本论文通过研究南祁连盆地二叠纪构造沉积演化过程,恢复盆地二叠纪不同时期原始面貌,可以为南祁连盆地二叠系油气勘探提供理论依据和基础资料。本文以“整体、动态、系统、综合”的思想为指导,在前人已有地质研究成果的基础上,综合应用地面地质调查、地球物理等手段,将野外调查和室内研究相结合,以南祁连盆地海相二叠系的地层划分对比为基础,恢复南祁连盆地二叠纪不同时期的盆地原型；以穿越盆地的多条大剖面为依托,对盆地的构造特征进行研究；利用平衡剖面技术恢复不同时期盆地的构造特征。从而,全方位、多角度的研究南祁连盆地二叠纪的演化过程。研究结果表明：南祁连盆地经历了中二叠世的海侵一晚二叠世的海退旋回。在勒门沟期,盆地整体为滨岸相沉积,属于坳陷型盆地；中二叠世草地沟期,海平面相对上升,形成了一个由北向南变深的三角洲-硅质碎屑滨岸-碳酸盐台地沉积体系组成的边缘坳陷盆地；在晚二叠世哈吉尔期,盆地形成自西向东由滨岸相-台地相沉积格局；到晚二叠世忠什公期,盆地不断萎缩,从而自东向西形成了河流相-三角洲相沉积的受限陆表海盆地。更多还原

【Abstract】 Southern Qilian basin is located in the southern part of Qilian fold belt, southwest adjacent to Qaidam basin, the northwest part is cutted off by sinistral strike-slip Altyn Tagh fault, the northern parts connect to the Middle Qilian block, the Southeast is linked together with the West Qinling.Many of the previous research mainly focused on Caledonian, Hercynian, indo-chinese period,but did a little research on the prototype basin and evolution process in Hercynian, indo-chinese period.Through the studies on the structural and sedimentary evolution of Permian Southern Qilian basin this article recovers the original Permian basin in different times so as to provide theoretical basis and base information for the gas and oil exploration of Permian Southern Qilian basin.This article takes "entirety,dynamic,system,integration"as the guidance, and is based on the existed geological research achievement, comprehensively uses region geological survey and geophysics method,also combine the outdoor survey with inside research. Based on Permian marine stratigraphic division of Southern Qilian basin, this article restores prototype basin in different period of Southern Qilian basin; Based on multiterm profiles through the basin, do research on the structural characteristics of basin; Make use of the balanced cross section technique to recover the structural characteristics of basin in different periods.Thereby, carry on the multiple perspectives, omni-directional research of the evolutionary process of Permian Southern Qilian basin.The research results indicate that South Qilian basin has experienced in the Permian transgression-Late Permian regression cycles.In Lemengou sedimentary period the basin was shore facies as a whole and belonged to depression basin;In the middle Permian Caodigou group sea level rose relatively and formed marginal depressions basin composing of a deep change from north to south Delta-siliciclastic and shore-shallow continental shelf-carbonate platform depositional system.In the late Permian Hajier sedimentary period the basin formed shore-carbonate platform sedimentary facies from west to east;To the late PermianZhongshigong group the basin shrinked constantly so that it became a restricted epicontinental sedimentary basin with river-delta facies from east to west. In the whole study area, the structural deformation of the sedimentary cover was very low and the intensity of the fault increased from east to west;The deformation intensity casued by folding process in southern Shinaihai-Caodabanshan profile was stronger than that in Hateer-Dayanglong profile; The Indosinian-Early Yanshanian regional tectonism dominated the eastern basin and the Late Yanshanian-Himalayan tectonism was dominant in the western basin.更多还原