徐淮地区下古生界—上元古界变形研究及意义

发布时间：2018-03-15 02:18

本文选题：变形分析　切入点：弧形构造　出处：《合肥工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文研究对象属于徐淮弧形构造,其位于华北板块的东南缘,其东部与郯庐断裂带、下扬子板块相接这样一个特殊部位,其研究成果对于正确认识弧形构造的形成机制与演化历史有着一定的科学意义。本文在系统收集和总结前人已有研究成果资料基础上,通过野外地质调查,以构造研究为主线,利用构造解析等手段,重点开展了对弧形构造的中段的地质构造研究。详细研究了下古生界与上元古界的构造变形特征,提出了下古生界主要发育大型斜歪褶皱、倒转褶皱、平卧褶皱、叠瓦扇形及逆冲断层体系；上元古界以大型的宽缓褶皱、侏罗山式褶皱及顺层滑脱断层为主要构造型式,并提出上元古界上部层面属于重要的滑脱层,为上覆构造的形成提供了制约条件。总结了研究区褶皱组合规律,提出了“爬坡—下坡”的褶皱发育模式。利用平衡剖面法计算了下古生界与上元古界变形量,得出下古生界地层缩短量为39.02%-62.86%；上元古界地层变形缩短量为16.13%。通过对研究区内下古生界与上元古界构造变形机制的分析,提出了徐淮弧形构造的形成机制属于运移变形受阻变形机制和挤压—重力滑覆动力学机制,并认为该区主变形阶段的动力来源于单一的SE方向。结合前人区域背景研究资料,总结了弧形构造的演化过程,提出T2-J1时期为挤压—重力滑覆,该时期两个阶段的演化奠定了弧形构造的基本轮廓。K1-E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；而新近纪以来,区内先存呈NNE-NE向构造普遍发生小幅度挤压,随之在区内发育了NW向断层,总体后期运动对该区影响相对较小
[Abstract]:The object of this paper belongs to the Xuhuai arc structure, which is located in the southeast margin of the North China plate, and the eastern part of it is connected with the Tanlu fault zone and the lower Yangtze plate. The research results have certain scientific significance for the correct understanding of the formation mechanism and evolution history of arc structure. Based on the systematic collection and summary of previous research achievements, this paper takes structural research as the main line through field geological survey. By means of structural analysis and other means, the geological structure of the middle segment of the arc structure is mainly studied. The structural deformation characteristics of the Lower Paleozoic and the Upper Proterozoic are studied in detail, and it is pointed out that the Lower Paleozoic mainly developed large skew fold and inverted fold. The main structural types of the Upper Proterozoic are large wide slow fold, Jurassic fold and bedding slip fault, and the upper layer of the Upper Proterozoic belongs to the important slip delamination. This paper summarizes the rule of fold assemblage in the study area, puts forward the fold development model of "climbing downhill", and calculates the deformation of Lower Paleozoic and Upper Proterozoic by using equilibrium profile method. The results show that the lower Paleozoic strata are shortened by 39.02-62.86and the upper Proterozoic strata by 16.13.The deformation mechanism of the Lower Paleozoic and Upper Proterozoic in the study area is analyzed. The formation mechanism of Xuhuai arc structure belongs to the mechanism of migration deformation and the mechanism of compression-gravity slip dynamics. It is considered that the main deformation stage in this area comes from a single SE direction. The evolution process of arc structure is summarized. It is suggested that the T _ 2-J _ 1 period is compression-gravity slip. The evolution of the two stages laid the basic outline of arc structure. K1-E period, under the background of regional extension, Since the Neogene, the preexisting NNE-NE trending structures have generally been squeezed slightly, and then NW-trending faults have developed in the area, and the overall late movement has relatively little influence on the area.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P542

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