【作者】 刘政；

【导师】 何登发；

【作者基本信息】 中国地质大学(北京) ， 矿产普查与勘探， 2012， 硕士

【摘要】 准噶尔盆地西北缘冲断带为中亚造山带重要组成部分，先后经历了海西、印支、燕山和喜马拉雅等多期构造运动，具有地质结构复杂，不整合结构广泛发育的特征。前人对该区进行了大量研究，但由于该区复杂的地质特征、火山岩体的发育及地震资料处理的技术等问题，对该区的构造特征与形成演化仍然存在较大争议。本文在前人研究的基础之上，选取哈拉阿拉特山及其以南乌－夏断裂带等区域作为研究对象，以沉积学、石油地质学、构造地质学、地震地质学及断层相关褶皱理论等理论为基础，结合哈拉阿拉特山区域野外露头资料、二维地震资料及相关井资料，对哈拉阿拉特山及其以南乌－夏断裂带的构造特征与形成演化进行了深入研究，并得出：1．区域内以逆冲断裂为主，断裂系统可分为上下两个构造体系，上部断裂具上陡下缓的特征，上端均终止于侏罗系内，下端收敛于二叠系底部滑脱面；下部为发育于石炭系或泥盆系内部的基底断裂，上端消失于石炭系与二叠系不整合面，底端则收敛于石炭系或泥盆系内的滑脱面。2．区域内存在多套不整合面：P1j/C、P2/P1、P2w/P2x、T/P、J/T、J1b/J1s、J1s/J2-3、K/J等，其中以P1j/C与T/J现象较明显，呈高角度不整合接触；表明该区经历多期的沉、隆作用，使研究区内地层的超覆或剥蚀尖灭现象相对发育。3．哈拉阿拉特山及乌－夏断裂带的形成为多期构造叠置的结果，东－西、南－北向上构造特征均具有较大差异性。石炭纪末期存在小规模逆冲作用，但其主要冲断作用始于二叠纪中后期，在二叠纪末－三叠纪初期时活动强度加大，之后进入相对稳定阶段，直至三叠纪末至侏罗纪初期构造活动达到高潮；这之后活动减弱，进入燕山－喜马拉雅调整期。4．乌－夏断裂带内的背斜均经历两期较大型的构造变形叠加作用，二叠纪中后期，受到北西－南东向挤压，形成了一系列较为平缓的褶皱；三叠纪末期到侏罗纪初期，因为哈拉阿拉特造山作用，使哈拉阿拉特山推覆体南侧沉积的二叠系发生强烈褶皱变形，最终形成了乌尔禾、风城和夏子街等一系列背形褶皱。更多还原

【Abstract】 The Northwestern margin of Junggar Basin is the important part of theCentral Asian orogenic belt. It underwent multiple structure movements, such asHercynian, Indosinian, Yanshan and Himalayan movement. The characteristics ofthis region are that the geological structure is very complicated and unconformitiesphenomenon are widely developmental. Due to its complex geological features,volcano rock development and lack of Seismic processing technique, althoughmany geological experts have made lots of research in this area, there are stillmany controversies in the aspects of its structure character and evolution.According to the previous studies of this area and the theory of Sedimentology,Petroleum Geology, Structural Geology, Seismic Geology and Fault-related foldtheoretic, combining the outcrops of Hala’alate Mountain, two dimensionalseismic data and well data, we select the Hala’alate Mountain and its southern area,Wu-Xia fault belt, as the research objects, doing the research on its structurecharacter and evolution. Through the above research, we get:1. This area is mainly controlled by reverse faults, the faults system can bedivided into two structure system. The upside of upper faults system disappearedin the Jurassic layer, with its attitude from gentle to steep, the lower part isconverged at the decollement in the bottom of Permian. The upside of lower faultssystem, which developed in the Carboniferous or Devonian, disappeared at theunconformity between the Carboniferous and Permian, the lower part is convergedat the decollement in the Carboniferous or Devonian.2. There are many unconformities in this region, such as P1j/C, P2/P1,P2w/P2x, T/P, J/T, J1b/J1s, J1s/J2-3and K/J et al. The P1j/C and T/J are moreobvious, contacting with high angular unconformity. These unconformitiesphenomenon indicate that the research area underwent multi-falling and uplift,which made the overlap and erosion developed widely.3. The formation of Hala’alate Mountain and Wu-Xia fault belt is the result of multi-structure activities, its structure character different from north to south, fromeast to west. There is small-scale thrust in late carboniferous. The main thrustingmovement begins after the middle Permian and strengthened during the end ofPermian to the beginning of Triassic and gradually becomes stable after that. Theclimax of thrusting period is during the end of Triassic to the early of Jurassic. Inthe period of Yanshan-Himalayan adjustment, the structure movement of thisregion is almost stagnant.4. The anticlines in Wu-Xia fault belt region experienced two large-scalesuperimposition of structure deformation. The first stage is that this region waspressed by the force from NW to SE, which formed these gentle folds during themiddle to the late of Permian. The second stage is that the orogeny of Hala’alatemade the deposition of Permian system at the southern of Hala’alate nappe foldedstrongly during the end of Triassic to the early of Jurassic. Finally these anticlines,such as Wu’erhe anticline, Fengcheng anticline and Xiazijie anticline, wereformed.更多还原