甘肃北山小西弓－红旗山地区中新生代变形构造及其形成机制

本文通过ＴＭ影像解译和野外验证，论证了研究区内近ＥＷ向构造带除在前中生代遭受了强烈的近ＳＮ向挤压变形外，还在中新生代叠加了脆－韧性和韧性两期近水平右扭剪切变形以及一期脆性变形，形成了现今的挤压带、剪切带和脆性断裂叠加的复杂构造格局。文中还对各期变形的最大主压应力方位、变形时代以及构造形成机制和演化进行了探讨。

MESO-CENOZOIC DEFORMATIONAL STRUCTURES AND THEIR FORMATION MECHANISM IN XIAOXIGONGHONGQISHAN AREA, BEISHAN, GANSU PROVINCE

On the basis of TM image interpretation and field identification,this paper has evidencedthat the sublatitudinal structureal zones in the study area not only suffered intense submeridional compression deformation during pre-Mesozoic period,but also brittle-ductile and ductilesubhorizontal dextral wrench deformation and brittle deformation during Meso-Cenozoic period,thus forming the present complicated structureal framework composed of superimposition of compressional zones,shear zones and brittle faults. In this paper,the orientation of themaximum principal compressive stress,deformation age,structureal formation mechanism foreach deformation stage,and structural evolution have been discussed as well.