铜陵地区古应力场分析及构造演化  

Analysis of Paleo-stress Field and Tectonic Evolution in Tongling Area

作　　者：刘国厅 LIU Guoting(Tongling Nonferrous Metals Group Copper Crown Mine Construction Co.,Ltd.,Anhui Tongling,244000 China)

机构地区：[1]铜陵有色金属集团铜冠矿山建设股份有限公司,安徽铜陵244000

出　　处：《工程建设（维泽科技）》2019年第7期55-61,共7页Engineering Construction

摘　　要：铜陵地区是我国著名的矿集区,前人研究表明其成矿受控于中生代中酸性侵入岩,而这些岩浆岩又受控于区域构造。因此,对铜陵地区古应力场进行深入分析研究,利于揭示该地区构造应力演化及解译复杂构造特征。铜陵地区构造复杂,是不同期次、不同构造活动叠加形成。因此,分析不同地层记录的应力痕迹及其变化是恢复该地区构造演化的重要手段。文章通过野外大量采集断层、擦痕、节理等数据,利用共轭断层、共轭节理分析主应力轴的方法,得出铜陵地区自志留系地层至新近系地层的应力场数据。印支期的应力场为220°→40°,形成了近EW向的铜陵褶皱群主体,同时形成了层间滑脱和顺层断裂构造,为后期的岩浆活动提供了构造空间;燕山期的应力场为170°→350°,伴随着郯庐断裂带NNE向平移运动,使得铜陵地区原近EW向的构造线产生逆时针转动被改造为NE向褶皱群,并使褶皱群产生近EW向的摆尾,同时形成近东西向宽缓褶皱;始新世末期的应力场方向为110°→290°,说明在白垩纪以后中国东部开始由区域性的多向挤压构造转换为伸展构造,在太平洋板块近E-W向的挤压作用下,形成枢纽方向为10°的第三期褶皱。说明利用大量的断层、擦痕、节理等数据,可以揭示铜陵地区构造应力场的变化,从而得出铜陵地区的构造演化,进而为控岩、控矿构造与成矿的关系以及深部找矿提供构造的基础数据。Tongling area is a famous mineral concentration area in China, and previous studies have shown that its mineralization is controlled by middle-acid intrusive rocks in the Mesozoic era, and these magmatic rocks are controlled by regional structures. Therefore, the ancient stress field in Tongling area is deeply analyzed and studied, which is helpful to reveal the evolution of tectonic stress and interpret the complex structural characteristics in this area. The structure of Tongling area is complex, which is formed by different stages and superimposed tectonic activities. Therefore, the analysis of stress traces and their changes recorded by different strata is an important means to restore the tectonic evolution in this area. In this paper, a large number of data such as faults, scratches and joints are collected in the field, and the principal stress is analyzed by using conjugated faults and conjugated joints. The data of the stress field from Silurian formation to Neogene formation in Tongling area is obtained. The stress field of Indosinian period is 220°→40°, forming the main body of Tongling fold group near EW direction, and forming the structure of interlayer slip and bedding fracture, which provides structural space for magmatic activities in later stage. The stress field in Yanshan period is 170°→350°. Along with the NNE translational movement in Tan-Lu fault zone, the tectonic line in the original EW direction in Tongling area is transformed into the NE fold group in counterclockwise direction, and the fold group is formed near EW direction and at the same time, the close east-west wide and gentle folds are formed. Stress at the end of the Eocene. The field direction is 110 °≤ 290 °, indicating that after the Cretaceous, the eastern part of China began to change from a regional multidirectional compression structure to an extensional structure, and the third stage fold with a hub direction of 10 °was formed under the compression of the Pacific plate near E ≤ W direction. It is shown that

关 键 词：铜陵地区 共轭断层 共轭节理 应力场 构造演化 

分 类 号：P618.13[天文地球—矿床学]