A TRIAL STUDY ON THE BASIC GEOLOGICAL FRAMEWORK IN SOUTHERN CHINA

摘要

The southern part of China includes Jiangsu, Zhejinag, Anhui, Shanghai, Hubei, Hunan, Jiangxi, Yunnan, Guangxi, Fujian, Guangdong, Hainan provinces, with a total area of 2,010,000 square kilometers. Since 1990's, many institutions within China have explored the area by means of magnetotelluric sounding with an emphasis on geological structures. The number of explored points amounts to more than 3,000, and dozens of geoelectric profiles deep to the bottom of lithosphere have been made. According to the data based on magnetotelluric sounding and surface geological survey, the basic geological framework in the southern China probably can be reconsidered and the structural units there be redivided. The crust and upper mantle in the southern China is characterized by multi-layers of conductivity. Vertically, they can be generally divided into such high conductivity layers as inter-crust, crust-mantle and inter-mantle. The inter-crust high conductivity layer can be subdivided into two upper crust high conductivity layers, layer 2-3, and one middle crust high conductivity layer; the high conductivity in the crust-mantle is distributed near the Moho, occasionally two layers; the high conductivity inside the mantle can usually be divided into the first high conductivity and the second high conductivity, occasionally a third can be found in the deep part of the mantle.