滇西地区构造形变特征  

CHARACTERISTICS OF TECTONIC DEFORMATION IN WESTERN YUNNAN AREA

作　　者：钟嘉猷[1] 

机构地区：[1]中国科学院地质研究所

出　　处：《地质科学》1992年第A12期50-59,共10页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学基金"滇川西部特提斯带岩石圈构造演化"的部分研究成果

摘　　要：作者根据多年来在滇两地区的野外考察和大量物理模拟实验结果,提出:1.本区处在印度板块向北推移时的东北端点的强烈挤压、剪切部位;2.由于这种特殊的受力形式,使得该区构造形变随挤压块体推进过程中几何形态在空间上的变化而改变着它们的活动方式和各部位的形态特征;3.由于受来自西南部印度板块与东部扬子断块的相向挤压,使得该区构造形变特征从北部开始,逐步向南由蠕滑变为冲断推覆,再过渡演变为走滑剪切带,区域上并伴有顺时针的旋扭作用;4.该区主要形变期为喜马拉雅期。The Southeastern part of Qinghai-Xizang plateau and Sangjiang area of Western Yunnan are Situated in a transitional region between the Circum-Pacific belt in Eastern China and Paleo-Mediterranean belt in Western China where the tectonic deformation and geological structures are very compliented. Based on mangyear field investigation data and results of model experiments, the structural deformation modes and characteristics of tectonic activity of the area are suggested in the following:1. The area is just located at the position of violent compression and shearing during northward movement of India Plate.2. Due to the special stress field, the tectonic deformation of the area with the spatial variation of geometric shapes of the compressed blocks, resulted in change of their movement modes and shapes of each parts. For example, a swarm of nappe structures the stress transform areas and deformation transform zone were formed.3. Due to the relative compresscion between the India and Yangtze plates, the tectonic deformation of Western Yunnan area is characterised by a geadual change from +he creep-slip in the north southwards to thrusting and napping and then to the strike-slip shearing along the Red River zone. Regionally, the clockwise rotation of the blocks occurred, with the largest angle of rotation about 120 °.4. The main deformation period is Himalayan Orogeny.

关 键 词：滇西地区 推覆构造 构造变形 

分 类 号：P542.3[天文地球—构造地质学]