武陵山区中新生代古构造应力场分析

发布时间：2018-03-29 09:02

本文选题：共轭节理　切入点：断层擦痕　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：我国南方地区海相油气历经了多轮油气勘探和研究,取得的共识认为,中上扬子整体结构、构造运动演化过程对古生界的改造保存条件是目前最突出的关键问题之一。中上扬子地区中新生代以来发生过多期次不同性质的褶皱运动和升降运动,构造演化过程十分复杂,存在不同方向、不同力学性质的构造形迹,构造形迹的成生发展过程存在很大争议,其主要原因是各期构造运动的性质及古构造应力特征(大小和方向)不明确。本文选取武陵山区典型共轭节理为主要研究对象,以区域构造背景为主要研究主线,在野外调查研究的基础上,通过古应力状态恢复,结合前人各方面资料,获得本区中新生代3期古构造应力场序列,从早到晚依次为:印支期、燕山早期、燕山晚期-喜山早期,其中构造应力场最大主应力主要为挤压,方向依次为近N-S向、近E-W向、近NWW-SEE向。通过区域地质背景分析,在结合共轭节理反演基础上,对武陵山区晚燕山-早喜山期构造应力场进行数值模拟,并进一步与该区构造地质相关现象进行对比,探讨武陵山区构造演化特征和地球动力学背景。模拟结果显示:最大主应力高值区主要分布在思南-印江断裂带和慈利-保靖断裂带相间部位以及齐岳山断裂中间位置;最小主应力低值区主要在断裂带内转折部位富集;剪应力带主要在断层处、断层产状变化处、断裂交汇处等处集中;齐岳山断裂带东北部和思南-印江断裂带西南部存在小区域正值,处于剪张应力状态,其他区域为负值,处于挤压应力状态;东西边界位移量最大,为3.39*10-8m,南北边界位移量中等,中心区域位移位移量最小,最小值接近于0。
[Abstract]:Marine oil and gas in the southern part of China have undergone many rounds of oil and gas exploration and research, and the consensus reached is that the overall structure of the upper and middle Yangtze, At present, one of the most prominent key problems is the transformation and preservation of Paleozoic during the evolution of tectonic movement. Since the Meso-Cenozoic in the Middle and Upper Yangtze area, there have been many times of fold movement and uplift movement with different properties, and the process of tectonic evolution is very complicated. The existence of different directions, different mechanical properties of structural traces, tectonic traces of the process of formation and development is very controversial. The main reason is that the nature of tectonic movement and the characteristics of paleotectonic stress (size and direction) are not clear. In this paper, the typical conjugate joints in Wuling Mountain area are selected as the main research object, and the regional tectonic background is taken as the main research thread. On the basis of field investigation, through the restoration of paleo-stress state and combining with the previous data, the three Paleotectonic stress field sequences of Mesozoic and Cenozoic in this area are obtained. The sequence from early to late is: Indosinian period, early Yanshanian period, and early Yanshanian period. In the late Yanshanian and early Himalayan periods, the maximum principal stress of the tectonic stress field is mainly squeezed, followed by near N-S direction, near E-W direction and near NWW-SEE direction. Based on the analysis of the regional geological background, combining with conjugate joint inversion, the maximum principal stress of tectonic stress field is obtained. The tectonic stress field of the late Yanshan-early Himalayan period in Wuling Mountain area is numerically simulated and further compared with the tectono-geological related phenomena in this area. The characteristics of tectonic evolution and geodynamic background in Wulingshan area are discussed. The simulation results show that the maximum principal stress region is mainly located in the interphase part of the Sinan-Indo-Jiang fault zone and the Cili-Baojing fault zone and the middle position of the Qiyueshan fault zone. The minimum principal stress is mainly concentrated at the turning point in the fault zone, and the shear stress zone is mainly concentrated at the fault, where the fault occurs and where the fault intersects. In the northeast of Qiyueshan fault zone and the southwest of Sinan-Injiang fault zone, there are small positive regions, which are in the state of shear tension stress, negative value in other regions, and compression stress state, the maximum displacement of east-west boundary is 3.3910 ~ (-8) m, and the displacement of north and south boundary is moderate. The displacement in the center region is the smallest and the minimum value is close to 0.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P542

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