徐淮地区构造变形特征与形成机制研究

发布时间：2018-01-15 17:39

本文关键词：徐淮地区构造变形特征与形成机制研究　出处：《合肥工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：徐淮弧形构造位于华北板块东南缘,苏鲁造山带的西侧,东缘以郯庐断裂带与扬子板块相接。研究区内主体褶皱与断裂轨迹平面上表现出一系列向北西西凸出的弧形。本文在系统收集和总结前人已有研究成果资料基础上,通过详细野外地质调查表明,徐淮弧形构造在南北向可分为北、中、南三段,东西向分为锋带、中带、根带三带,垂向分为下部构造层、中部构造层、上部构造层的特征,提出“九宫格”式的构造变形模式。通过对徐淮弧形构造北段和中段断层应力场反演表明,弧形构造形成于区域挤压背景下,主压应力方向为SE-NW向,另外晚期伸展背景下发育正断层,拉张应力方向亦为SE-NW向。在此基础上,结合原始地层沉积环境、区域构造背景,提出了徐淮弧形构造的形成机制属于挤压-重力滑覆动力学机制。对徐淮弧形构造进行数值模拟研究,充分验证了弧形构造形成的动力学背景是来自南东方向的挤压力,肯定了弧形构造形成的挤压-重力滑脱机制,模拟出南北两侧的边界隐伏断裂对徐淮弧形构造形成的限制作用。在上述野外地质调查、断层应力场反演、数值模拟技术的应用,地层间不整合事件与出露岩体的时代综合研究的基础上,总结徐淮弧形构造的演化过程,提出T2-K1时期为主变形期,该时期两个阶段的演化奠定了弧形构造的基本轮廓。K1-E1时期,在区域伸展作用背景下,使得区内先存逆断层复又发生伸展正断,以及东部的断陷盆地发育。而新近纪以来,区域逆冲挤压对徐淮弧形构造的影响较小,区内构造变形微弱。因此,徐淮弧形构造变形的形成起源于华北、华南板块的陆-陆碰撞,指示中国东部早期受控于南北板块汇聚的古特提斯构造向滨太平洋构造转换。
[Abstract]:Xuhuai arc structure is located in the southeastern margin of the North China plate and the west side of the Sulu orogenic belt. In the eastern margin, the Tan-Lu fault zone is connected with the Yangtze plate. A series of arcs protruding northwestward on the surface of the main fold and fault locus in the study area are presented. This paper systematically collects and summarizes the data basis of previous research achievements. Go. The detailed field geological survey shows that the Xuhuai arc structure can be divided into north, middle, south, east and west front zone, middle zone, root zone three zones, vertical divided into lower tectonic layer, central tectonic layer. Based on the characteristics of the upper tectonic layer, a "H5 home page" tectonic deformation model is proposed. The inversion of the fault stress field in the north and middle sections of the Xuhuai arc structure shows that the arc structure was formed in the regional compression background. The direction of principal compressive stress is SE-NW direction, the normal fault is developed in the late extensional setting, and the direction of tensile stress is SE-NW direction. On this basis, combined with the original sedimentary environment, the regional tectonic background. The forming mechanism of Xuhuai arc structure is put forward, which belongs to the mechanism of compression-gravity slip dynamics, and the numerical simulation of Xuhuai arc structure is carried out. It is fully verified that the dynamic background of the arc structure formation is the extrusion force from the south to east direction, and the compression-gravity slip mechanism of the arc structure formation is confirmed. The effect of the boundary hidden faults on the formation of the Xuhuai arc structure is simulated. The application of the field geological survey, the inversion of fault stress field and the numerical simulation technology. On the basis of the comprehensive study of the age of interstratigraphic unconformity events and outcrop rock mass, the evolution process of Xuhuai arc structure is summarized, and the main deformation period of T2-K1 period is put forward. The evolution of the two stages of this period laid the basic outline of the arc structure. K1-E1 period, under the background of regional extension, the overlay of the thrust fault and the extension of the normal fault occurred in the area. Since the Neogene, the influence of regional thrust compression on the Xuhuai arc structure is relatively small, and the tectonic deformation in the area is weak. Therefore, the formation of Xuhuai arc structural deformation originated in North China. The continental-continental collision of the South China plate indicates that the early eastern part of China was controlled by the transition of the paleotesian tectonics converging from the north and south plates to the riparian Pacific tectonic.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P542

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