川东南构造几何学与运动学特征及其与雪峰山西段的构造关系探讨

发布时间：2018-05-13 07:48

本文选题：川东南构造带 + 湘鄂西构造带　；参考：《中国地质大学(北京)》2016年博士论文

【摘要】：雪峰山陆内复合构造系统是目前研究的热点问题,而川东南-湘鄂西地区位于该系统的西界,对于川东南-湘鄂西地区的构造特征和构造演化的研究是深入研究雪峰山陆内复合构造系统的基础,同时川东南地区是油气资源勘探的重点区,研究其构造特征和演化对油气勘探有一定的指导作用。本文以构造地质学和断层相关褶皱理论等为基础,综合应用野外地质考察资料、地震剖面资料和钻井资料,将野外实测剖面、浅表地质剖面与地震剖面结合分析川东南构造带和湘鄂西构造带的构造几何学特征,并应用运动学分析方法建立动态的构造运动学模型分析其构造演化特征,探讨川东南构造带与湘鄂西构造带的构造关系。同时对野外采集的样品进行磷灰石裂变径迹实验分析来进一步厘定川东南地区的构造变形时间。川东南褶皱带及湘鄂西西北部在燕山期以来主要经历三次抬升:在约89Ma达到最大埋深并进入缓慢抬升阶段,在约28Ma进入快速隆升阶段,在约20Ma隆升速率减慢。川东南大部分地区白垩系及新生界的沉积都被剥蚀。川东南构造带划分为四个褶皱带,主要受4套滑脱层控制:基底前震旦系变质岩滑脱层、深部寒武系泥页岩和膏岩滑脱层、中部志留系泥页岩滑脱层和浅部三叠系嘉陵江组膏岩滑脱层。四个褶皱带的所有背斜的构造均可划分为浅层构造层、中层构造层、深层构造层和基底构造层。川东南构造带各层的缩短量不同,川东南地区空间收缩变形最大达到四分之一,最小为七分之一,大部分地区的空间收缩变形为六分之一到五分之一之间。四个褶皱带的背斜构造变形时间为晚白垩世-古近纪和新近纪,构造变形主要受到晚燕山运动和喜马拉雅运动的影响。湘鄂西构造带垂向上主要发育三套滑脱层,分别是震旦系的滑脱层和前震旦系的两套滑脱层。湘鄂西地区的向斜和背斜构造的形成时间主要是加里东期-海西期和印支期。湘鄂西构造带褶皱形态为隔槽式褶皱形态,而过渡带褶皱形态为等宽箱状褶皱形态,川东南构造带褶皱形态为隔档式褶皱形态,这三个相邻褶皱带的褶皱形态为褶皱形态发展的不同形态阶段。川东南地区存在着多期次多层滑脱变形的特征,川东南-湘鄂西地区处于雪峰山陆内造山带的逆冲推覆构造带,推覆构造受到南东-北西向的水平挤压作用下沿滑脱层滑动,从南东向北西发生递进衰减变形。
[Abstract]:The complex tectonic system in Xuefeng Mountain is a hot research topic at present, and the southeast of Sichuan and the western part of Hunan and Hubei are located in the western boundary of the system. The study of the structural characteristics and tectonic evolution in the southeast of Sichuan and the western part of Hunan and Hubei is the basis for the in-depth study of the complex structural system in the Xuefeng Mountains, and the southeast part of Sichuan is the key area for the exploration of oil and gas resources. The study of its structural characteristics and evolution has a certain guiding role for oil and gas exploration. On the basis of tectonic geology and fault-related fold theory, this paper synthetically applies field geological survey data, seismic profile data and drilling data. The structural geometry characteristics of the southeastern Sichuan tectonic belt and the western Hunan Hubei tectonic belt are analyzed in combination with the shallow geological profile and the seismic section, and the dynamic tectonic kinematics model is established to analyze the tectonic evolution characteristics by using the kinematics analysis method. The structural relationship between the southeast Sichuan tectonic belt and the western Hunan-Hubei tectonic belt is discussed. At the same time, the fission track analysis of apatite was carried out to determine the tectonic deformation time of southeast Sichuan. Since the Yanshanian period, the southeast Sichuan fold belt and the northwest of Hunan and Hubei mainly experienced three uplifts: at about 89Ma reaching the maximum buried depth and entering the stage of slow uplift, at about 28Ma entering the stage of rapid uplift, and at about 20Ma, the rate of uplift slowed down. The Cretaceous and Cenozoic deposits in most parts of southeast Sichuan were denudated. The southeast Sichuan tectonic belt is divided into four fold zones, which are mainly controlled by four sets of slip beds: basement Psinian metamorphic detachment, deep Cambrian mudstone and gypsum detachment. The central Silurian shale slippage layer and shallow Triassic Jialingjiang formation gypsum detachment layer. All the anticlines in the four fold belts can be divided into shallow layer, middle layer, deep layer and basement layer. The shortening of each layer in the southeast Sichuan tectonic belt is different. The spatial shrinkage deformation of southeast Sichuan is 1/4, the minimum is 1/7, and the shrinkage deformation of most areas is between 1/6 and 1/5. The anticline tectonic deformation of the four fold belts occurred in the late Cretaceous Paleogene and Neogene. The tectonic deformation was mainly influenced by the late Yanshanian and Himalayan movements. There are three sets of slip layers mainly developed in the vertical direction of the western Hunan and Hubei tectonic belt, which are the slippage layers of the Sinian system and the two sets of slippage layers of the pre-Sinian system. The formation time of syncline and anticline in the west of Hunan and Hubei is mainly Caledonian-Hercynian and Indosinian. The fold form of Xiang-Hubei structural belt is secluded fold form, while that of transitional zone is equal-width box fold form, and that of southeast Sichuan structural belt is separated fold form. The fold morphology of the three adjacent fold zones is different morphological stages of fold morphology development. There are many times and multiple layers of slip deformations in southeast Sichuan. The southeast Sichuan-Xiang-Hubei area is located in the thrust nappe tectonic belt of the Xuefengshan intracontinental orogenic belt, and the nappe structure is sliding along the slip layer under the action of horizontal compression in the south-east-northwest direction. Progressive attenuation deformation occurs from south to east to north and west.
【学位授予单位】：中国地质大学(北京)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P542

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