相山火山盆地北部地区构造特征研究

发布时间：2018-04-03 08:14

本文选题：相山火山盆地　切入点：褶皱　出处：《东华理工大学》2015年硕士论文

【摘要】：江西相山早白垩世火山盆地位于近东西向赣-杭构造火山岩型铀成矿带与南北向大王山-于山花岗岩型铀成矿带的交汇处,发育于青白口系浅变质岩组成的雪峰-加里东期北东东向潭港-相山复式背斜的核部。本论文依托中国地质调查局“相山火山盆地三维地质调查”项目,在详细收集分析相山火山盆地地层、构造等资料的基础上,通过野外精细构造剖面测制、路线勘查、探槽揭露、节理统计分析,结合近年来获得的钻孔资料,系统研究了相山火山盆地,特别是北部地区的主要构造特征。论文主要取得了以下几点成果与认识:(1)相山火山盆地发育于青白口纪浅变质基底之上,经南北向挤压的雪峰-加里东期构造运动,基底变质岩系形成北东东向褶皱,由北向南分别为培坊倒转向斜、潭港-相山复式背斜和南美峰向斜。相山火山盆地发育于潭港-相山复式褶皱东端核部。(2)相山火山盆地北部地区发育有三条北东向主干断裂,即邹家山-石洞断层和巴前-袁家山断层和布水-上泥浆断层,受遂川-德兴深断裂的影响,这些北东向断层为研究区的主要构造行迹,其活动具有明显的阶段性,加里东期-燕山期主要以左行走滑为主,燕山晚期表现为伸展拉张作用,喜山期则主要体现为区域挤压作用。(3)相山火山盆地北部地区近东西向逆断层为一系列产状一致,性质相似的高角度逆断层,形成时间可能早于早白垩火山活动时间。该断层可能形成时代可追溯致加里东期,伴随近东西向复式背斜的形成而产生,具有多期活动的特征。相山火山盆地北部近东西向逆断层可能经历了以下演化阶段:加里东期,在基底复式褶皱形成过程中,形成与褶皱枢纽产状一致的纵向逆断层。后期随着北东向遂川断裂及其旁侧同向的断层活动,这些近东西向断层作为北东向断层的次一级断层也发生活动。由于北东向断层的左行走滑,导致沿其旁侧的近东西向断层在局部应力场下发生逆冲作用。燕山中期,由于大规模的岩浆活动使得地壳深部岩浆上涌并产生侧向挤压,在北部盆地边缘先存的这些近东西向断层进一步发生逆冲活动,并在火山活动晚期,次火山岩随断裂面侵入形成岩墙。燕山晚期至喜山期,在区域内挤压、拉张作用的影响下,这些近东西向断裂随着其旁侧主断裂一起复活,在局部拉张和挤压的应力场下发生逆断层活动。
[Abstract]:The early Cretaceous volcanic basin of Xiangshan, Jiangxi Province, is located at the junction of the near east-west tectonic volcanic rock-type uranium metallogenic belt and the south-north Dawangshan-Yushan granite type uranium metallogenic belt.The core of the Xuefeng-Caledonian East-West Xiangtan-Xiangshan anticline developed in the Qingbakou shallow metamorphic rocks.This paper relies on the project of "Three-dimensional Geological Survey of Xiangshan volcanic Basin" of China Geological Survey, on the basis of collecting and analyzing the stratigraphic and structural data of Xiangshan volcanic basin in detail, and through the fine structural profiling and route exploration in the field,The main structural characteristics of Xiangshan volcanic basin, especially in the northern part of China, are systematically studied by means of trench disclosing, joint statistical analysis and drilling data obtained in recent years.The main achievements of this paper are as follows: (1) the Xiangshan volcanic basin developed on the Qingbakou shallow metamorphic basement. The basement metamorphic series formed east-west fold through the south-north compressional Xuefeng-Caledonian tectonic movement.From north to south, they are Peifang inverted syncline, Tangang-Xiangshan anticline and South American peak syncline.The Xiangshan volcanic basin is developed in the core of the eastern tip of the Xianggang Xiangshan fold.) in the northern part of the Xiangshan volcanic basin, there are three main faults in the NE direction, namely, the Zoujiashan-Shidong fault, the Ba-Qian-Yuanjiashan fault and the Bushui-Upper mud fault.Influenced by the Suichuan-Dexing deep fault, these faults are the main tectonic tracks in the study area, and their activities have obvious stages. The Caledonian to Yanshanian periods are mainly left strike-slip, and the late Yanshanian faults are extensional and extensional.The Himalayan period is mainly reflected by regional compression. 3) the near east-west thrust faults in the northern part of Xiangshan volcanic basin are a series of similar high angle thrust faults, which may be formed earlier than the early Cretaceous volcanic activity.The fault may be formed in the Caledonian period with the formation of the near east-west composite anticline and has the characteristics of multi-stage activity.The near east-west thrust faults in the northern Xiangshan volcanic basin may have undergone the following evolution stages: in Caledonian period, longitudinal thrust faults were formed in the process of the formation of the basement composite folds, which are consistent with the occurrence of the fold hinge.In the latter stage, with the activity of NE-trending Suichuan fault and its flanking faults, these near-EW-trending faults are also active as the subprimary faults of NE-trending faults.Due to the left strike-slip of the NE-trending fault, the near-east-west fault along the side of the fault thrust under the local stress field.In the middle Yanshanian period, because of the large-scale magmatic activity, the deep crust magma upwelled and produced lateral compression. These near-east-west faults that existed in the northern margin of the basin occurred further thrusting, and in the late period of volcanic activity,Subvolcanic rocks intrude into the fault surface to form a rock wall.From the late Yanshanian to the Himalayan period, under the influence of regional compression and extension, these near-east-west faults were revived along with the main faults, and the thrust faults occurred in the local stress field of Zhang He.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P542

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