【作者】 李天斌；

【导师】 宋鸿林；

【作者基本信息】 中国地质大学（北京） ， 构造地质学， 2006， 博士

【摘要】 本文在充分利用前人研究成果的基础上，对鄂尔多斯西缘桌子山—贺兰山、牛首山—六盘山等地关键地区的地质构造和沉积特征进行了详细野外调查研究，证实和证伪了一些争议或不清楚的问题，取得了以下新认识和主要研究进展： 1、鄂尔多斯西缘6阶段沉积—构造演化历史，包括：太古—古元古代末结晶基底形成阶段、中—新元古代至奥陶纪稳定大陆边缘沉积阶段、加里东运动逆冲推覆构造启动阶段、晚古生代—三叠纪海陆交替和陆内湖盆形成阶段、侏罗纪—新近纪逆冲推覆构造主要发展阶段和新生代持续逆冲推覆阶段。鄂尔多斯西缘多期逆冲推覆构造作用伴随泥盆纪(六盘山地区)、侏罗纪—白垩纪和古近纪—新近纪(局部地区)的多期前陆盆地发育。 2、建立了鄂尔多斯西缘逆冲推覆构造体系，由冲断层系统、推覆体／冲断体／褶冲带／前陆或后展盆地、冲断席、冲断及伴生构造组成五级构造，分为5个一级、11个二级和26个三级构造单元；并详细阐述了各单元的构造特征。 3、鄂尔多斯西缘北段为贺兰山冲断层系统，包括由阿拉善结晶冲断席和华北前陆褶冲带组成的原地和外来冲断层构造体系，前锋为桌子山—横山堡陆缘褶冲带；至少存在3期冲断层作用，第1期发生在侏罗纪末，至少存在沿结晶基底中的三个主滑脱面发生的大规模冲断层作用。第2期形成了具有上、下两个构造层的宗别立—正义关大型异地推覆体，主滑脱面为石炭—二叠系中的煤系地层，构成复杂的双冲构造和联冲构造。第3期在东部形成陆缘褶冲和反冲构造带的同时，在西部将异地推覆体下部的奥陶系推至地表。 4、鄂尔多斯西缘南段六盘山弧形冲断层系统至少存在4期冲断层作用，无结晶基底卷入；第1期(加里东末期)的逆冲推覆作用使西部志留系不整合地体向NEE逆冲推覆在华北陆缘无志留纪沉积的地体之上；第2期(早—中泥盆世)的褶皱冲断层作用将下伏的华北陆缘奥陶系再次逆冲至志留系不整合地体之上；第3期(侏罗纪—白垩纪)和第4期(古近纪—新近纪)的逆冲推覆作用由西南向东北减弱，前锋为马家滩—惠安堡舌形陆缘褶冲带。 5、上述两套冲断层系统分别形成独立的呈弧形展布的逆冲推覆构造体制，前端均为陆缘褶断带，中段表现为由“原地”或“外来”地体组成的多重逆冲推覆冲断席，发育多个主滑脱层和双冲构造：后部形成拉伸盆地，符合前陆冲断层一般模式。二者之间在贺兰山南段和卫宁北山出现构造复合域，在马家滩—横山堡以东存在构造弱化域。冲断席的中段前部位移最大变形最强，两侧和后部位移渐小变形渐弱。冲断席之间和两侧为具走滑或斜滑性质的联冲构造。六盘山弧形冲断层系统中的第1、3期和贺兰山冲断层系统的第1、2期冲断层作用具有逆冲推覆性质，累计位移幅度可能分别达到170km和60～80km。更多还原

【Abstract】 Based on fully using the predecessor’s achievement in geological research, this paper carried on detailed investigation and research about the geological structure and sedimentary characteristics of the key region of the Zhuozishan-Helanshan, Niushoushan-Liupanshan in the west margin of Ordos basin, testified and falsified some controversial or unclear problems, the new views and main research progress as follows:1. The deposition-tectonics evolutionary history in the west margin of Ordos basin include 6 stages: crystalline basement formation stage in the Archaean-Terminal Palaeoproterozoic, stable continental-margin deposition stage in Middle-late Proterozoic-Ordovician, starting stage in the Caledonian thrust nappe structure, marine-continental alternation and inland lake basin formation stage in the late Palaeozoic-Triassic, dominant development stage of the thrust nappe structure in the Jurassic-Neogene period and continuously thrusting nappe stage in the Cenozoic period. Multistage thrust nappe structure function in the west margin of Ordos basin associated with the multistage foreland basin formation in the Devonian period (Liupanshan region), Jurassic-Cretaceous period and Palaeogene-Neogene period (partial region).2. The thrust nappe structure system in the west margin of Ordos basin consists of thrust fault system, nappe /thrust bodies/fold-thrust belts /foreland or back extentional basins, thrust sheets, thrust and its companionate structure. The system is divided into 5 first order structure, 11 second order r structure and 26 third order structure units; elaborated the structure characteristics of each unit in detail.3. The northern segment in the west margin of Ordos basin is a compound thrust system of the Henanshan, including the Alashan crystalline thrust sheet and autochthones or allochthones thrust structure system of north China, its front is continental margin fold-thrust belt of the Zhuozishan-Hengshanpu; There exists at least 3 stage thrust functions.The first stage took place in the Terminal Jurassic period, had at least three large-scale thrust functions along the three main detachment surfaces of the crystalline basement.The second stage formed the large-scale Zongbieli-Zhengyiguan allochthone nappe which has upper-lower double structure layers ,its main detachment is the coal bearing strata of the Carboniferous-Permian system, and constituted complicated duplex and link thrust. The third stage pushed the Ordovician System of the lower allochthone nappe to the Earth’s surface in the western part, while in the eastern part formed continental margin fold-thrust and recoil fault belts in the meantime.4. There exists at least 4 stage thrusting functions in the Liupanshan arcuate thrust system of the southern segment in the west margin of Ordos basin, of which have no involvement of crystalline basement; The thrust nappe function of the first stage (Terminal Caledonian) mad the western Silurian uncomfortable terrace towards更多还原