Characteristics and Genesis of Two Types of Tectonic Deformation During Caledonian in Eastern Guizhou and Northern Guangxi
Taking place in Eopaleozoic,Caledonian movement caused strong deformation in southern China and was mainly represented by episodic movements of Duyun and Guangxi.Comprehensive research on tectonic deformation and sedimentary environment holds that Duyun movement,as a local one,evidently influenced the middle and southern parts of Guizhou,the western area of Kaili-Sandu fault.Whereas,Guangxi movement orig-inated from the squeezing of the Yangtze block and the Cathaysian block along the Jiangshan-Shaoxing fault. Under the influence of time and space,together the two movement events have formed two types of tectonic char-acteristics bordered by fault fracture.To the west of the fault fracture,this area is mainly influenced by Duyun movement and structures like EW folds and normal faults are developed.To the east,Guangxi movement shows its power,and structures such as NE folds and shear zones can be seen.The time of the occurrence of Guangxi movement is determined by samples collected from the study area.Among which samples from the ductile shear zone in Gaowu show that the plateau age of 40Ar/39Ar of muscovite is (41 6.4 ±1.8)Ma,and isochron dating is (41 7.7 ±1.8)Ma;those from NE cleavage belt in Liping show that the plateau age of 40Ar/39Ar of sericite is (426.5 ±2.3)Ma,and isochron age is (437 ±1 0)Ma.
Caledonian movementEW deformationNE deformation40 Ar-39 Ar geochronologyeastern Guizhou and northern Guangxi
国家科技期刊平台
NSTL
万方数据
维普
