GEOLOGICAL CHARACTERISTICS AND PROGNOSIS IN THE PERIPHERY OF DACHANG ANTIMONY OREFIELD IN GUIZHOU PROVINCE

The large scale Dachang antimony orefield is located in the southwest of Guizhou Province. The Upper Permian "Dachang layer" is the major ore-bearing layer. The orebodies occur mainly in the top of the strongly altered secondary quartzite and the lower part of clay rock. The regional NE-trending faults and second-order folds and faults are the major ore-controlling structures. The tenso-shear faults and interstratified faults are developed, serving as important host structures. Based on the ore-controlling factors in the orefield, two prospective targets are delineated.