Abstract:

 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 originated 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 characteristics 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 (416.4±1.8) Ma, and isochron dating is (417.7±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±10) Ma.

Key words:  Caledonian movement, EW deformation, NE deformation, ⁴⁰Ar-³⁹Ar geochronology, eastern Guizhou and northern Guangxi