The Research Of Tectonic Evolution In Southern Guizhou Depression

Southern Guizhou depression is mainly a residual basin which filled from Paleozoic to Triassic. The evolution of the role of being multi-stage tectonic movements, from the Late Triassic after the Depression by the Indo-China, Yanshan, Himalayan movement role, early formation, where a strong uplift and denudation, tectonic deformation is more intense, complex tectonic conditions. Depression at the same time, oil and gas geological exploration and research at an early stage, depression tectonic framework, structure and evolution of deformation characteristics of knowledge was not clear enough. I predecessors in collecting and collating information on the basis of the results through the integration of surface geological and geophysical (gravity, magnetic, MT and seismic) data, combined with sedimentary facies and palaeogeographic information, etc., using the theory of plate tectonics, basin analysis, marine carbonate sedimentary theory and balanced cross-section technology, methods and means to study the tectonic pattern of depression, tectonic deformation and evolution characteristics of depression.At the regional geology, geological field surveys, heavy, magnetic and seismic data on the basis of the study, obtained southern Guizhou depression in the Pacific, Tethyan tectonic domain with a combination of flat areas, while development of Tethys (NW direction) and the Pacific Ocean coast (NE-NNE direction) structural characteristics. Their basement in Upper Proterozoic metamorphosed strata, depth of basement depth southwestern large buried depth of the Northeast, where the greatest depth Changshun depression.Based on different periods of depression filling characteristics and tectonic line direction, can be divided into southern Guizhou depression Upper Paleozoic, Lower Paleozoic and Middle Mesozoic-Cenozoic structural layer and the three "three-convex a concave one-off bands" five tectonic units,Depression cap rock deformation to reflect the characteristics of a typical mountain forward setting off, the more close to the Xuefeng uplift the greater the intensity of ground deformation. Deformation characteristics according to differences in depression can be divided into the eastern thrust deformation zone, the southern fold and thrust deformation zones, the western double synclinal deformation zones in the north and central parts of fault block deformation zone folding compartment trough five deformation zones of deformation zone. Tectonic style dominated by fault-related fold, multi-developmental basement involved thrust folds.Formation and evolution of depression experienced four Fort, Wuling, Caledonian, Hercynian, Indo-China, Yanshan, seven Himalayan tectonic events, divided into basal formation (Proterozoic), peaks the western edge of a passive continental margin rift basin (Aurora-Middle Ordovician), foreland basin (Late Ordovician-Silurian), Yangtze ancient land south-west margin rift basin (Devonian-Middle Triassic), foreland basin (Late Triassic-Early Jurassic), land reform within the basin (Late Jurassic-present) six stages. Caledonian and Hercynian in which the main filling for the Depression period, Indo-China and Yanshan major transformation for the Depression period.