【作者】 张义楷；

【导师】 周立发；

【作者基本信息】 西北大学 ， 矿产普查与勘探， 2007， 博士

【摘要】 鄂尔多斯西缘及邻区是中国东部滨太平洋构造域和西部特提斯构造域两大构造动力体系的转换枢纽带。特殊的构造位置，中新生代以来印支、燕山、喜马拉雅多期次不同构造体系的复合与叠加作用，同期次不同构造体系联合与制约作用，使得研究区构造变形十分复杂，油气地质条件多变，油气成藏条件各地极不平衡，这给研究区油气勘探前景的客观评价带来了诸多不确定的因素，使得该区油气勘探迄今尚未获得重大突破。因此，开展《鄂尔多斯西缘中新生代构造体制转换与油气聚集》研究，将有助于确定研究区及邻区中新生代不同阶段成盆作用及改造作用的动态过程，有助于更好地理解构造作用及其叠加关系对研究区油气生成、运移、聚集、保存的影响，有助于从动态演化的角度对研究区油气勘探目标进行客观评价，从而为油气勘探目标的优选提供充足的证据。论文以沉积盆地动力学理论为指导，以构造沉积综合分析方法为研究手段，以地面地质、井下地质、地球物理、地球化学方法和各种分析测试资料为基础，以成盆作用及改造作用的动态过程为主线，深入开展了研究区及邻区中新生代构造特征、不同构造旋回的盆地原型、以及构造应力场特征及其转换与油气聚集关系的研究。中新生代构造特征研究表明：研究区及邻区的中新生界可以划分为印支构造层、燕山构造层和喜马拉雅构造层。研究区印支构造层与燕山构造层之间多以平行不整合或微角度不整合接触，说明该区印支期构造变形特征并不明显，故难以对其构造单元进行确定和划分；以燕山构造层的构造变形为依据，可将研究区燕山期构造划分为：巴彦浩特—六盘山古隆起区、乌海—平凉古复背斜构造带和天环古向斜三个构造单元；以喜马拉雅构造层的构造变形特征为依据，可将研究区喜马拉雅期构造划分为：河套—银川伸展构造系，石沟驿—平凉转换构造系和六盘冲断构造系三个构造单元。根据对中新生界不同构造旋回盆地原型的研究，论证了中新生代盆地的演变过程。研究认为：晚二叠世—早中三叠世研究区及邻区整体属大华北克拉通盆地的组成部分；晚三叠世则属挤压型克拉通挠曲坳陷；早中侏罗世属大鄂尔多斯克拉通内坳陷盆地的组成部分；中晚侏罗世属挤压型克拉通挠曲坳陷；晚侏罗世属冲断山前坳陷；早白垩世发育伸展背景下的差异坳陷。通过对中新生代构造应力场与油气聚集关系的研究，认为研究区已经具备了优越的生储盖组合，中新生代构造应力场控制下的以继承性的挤压作用为主的构造活动是影响研究区油气最终聚集与成藏的关键因素。更多还原

【Abstract】 Western Ordos region and its adjacent area is the geological & geophysical divide or transform hinge between circum-Pacific tectonic domain in eastern China and Tethyan tectonic domain in western China. Due to its particular tectonic location, this area had undergone multi-phase Compound and superimpose and single-phase combinate and restrict of different tectonic domain of Indosinian, Yanshanian and Himalayan from Mesozoic-Cenozoic, then develop a complex structural pattern and unbalanced petroleum geological conditions and hydrocarbon accumulation conditions. Then till today the exploration activity has not got a satisfied result because there have a good deal of uncertain factor in the Objective evaluation of Petroleum prospect controlled by the complicated geology conditions. So, based on the intensive study of the transition of the Mesozoic-Cenozoic tectonic regimes and hydrocarbon accumulation in western Ordos Region, the dynamic process of multi-phase basin formation and modification of the Mesozoic-Cenozoic in Western Ordos region and its adjacent area can be confirmed, the relationship between the generation, migration, accumulation and preservation of hydrocarbon and tectonic action and its superimpose can be understood, petroleum exploration targets can be evaluated objectively through a dynamic view. Then the results of the research provide the geologic basis for selection of petroleum exploration targets.Guide by the principles of sedimentary basin dynamics, by means of tectono-depositional analysis, combining surface and subsurface geologic analysis, geophysical and geochemical techniques along with testing data the structural characteristics of the Mesozoic-Cenozoic, prototype basin of different tectonic cycle, the relationship between transition of the Mesozoic-Cenozoic tectono-stress field and hydrocarbon accumulation in western Ordos Region and its adjacent area has been studied through the view of dynamic process of multi-phase basin formation and modification.The study of the tectonic feature of the Mesozoic-Cenozoic showed that the Mesozoic-Cenozoic in western Ordos Region and its adjacent area can be subdivided Indosinian, Yanshanian and Himalayan tectonic sequences. The contact relationship of parallel unconformity or lower angular unconformity between Indosinian and Yanshanian tectonic sequences showed that the tectonic deformation of Indosinian is scarcely notable. Based on the tectonic deformation of Yanshanian tectonic sequences, the structure of Yanshanian can be subdivided into three units, Bayanhaote-liupanshan palaeohigh, Wuhai-Pingliang palaeoanticlinorium tectonic zone, Tianhuan palaeosyncline. Based on the tectonic deformation of Himalayan tectonic sequences, the structure of Himalayan can be subdivided into five units, Hetao-Yinchuan extensional tectonic system, Shigouyi-Pingliang transform tectonic system, Liupanshan thrust-fault tectonic system.The study of prototype basin of different tectonic cycle showed that the basin of the Mesozoic-Cenozoic has evolved in different regimes in the western Ordos region and its adjacent area, which include the western part of great northern-Chinese cratonic basin from late Permian to early-middle Triassic, crooked-downwarp within compressional craton during late Triassic, the western part of depression basin within great Ordos craton during early-middle Jurassic, crooked-downwarp within compressional craton during middle-late Jurassic, piedmont depression controlled by thrust fault during late Jurassic and differential settlement under extension during early Crataceous.The study of the relationship between transition of the Mesozoic-Cenozoic tectono-stress field and hydrocarbon accumulation showed that there have superior source-reservoir-cap rock combinations in the western Ordos region. Its adjacent area and the tectonic activities which is mainly in inherited compressional regime controlled by the Mesozoic-Cenozoic tectono-stress field is the key element for the hydrocarbon accumulation.更多还原