GENERAL FEATURES OF THE WESTERN GUANGDONG NAPPE TECTONIC SYSTEM AND ITS CONTROL ON THE NOBLE METAL AND POLYMETALLIC DEPOSITS

The western Guangdong nappe tectonic system was formed in the Hercynian and Indosinian epech. Its tectonic styles belong to the folding and thrusting nappe structure, the extended way is piggyback propagaton. The allochthon consists of the Presinian, Sinian and Cambrian Systems. The autochthon comprises the Devonian and Carboniferous Systems. The most of the subsidiary thrusting fracture shows the plough-shaped with the upper steep and the lower flat form. The structure assemblage of the nappe tectonic system is perfect in the cross section, and the structure belts andthe tectonic units show the mineralization and controling ore deposits, which can be divided into the five-types according to the occurrence condition:①the ore in the flat of gliding nappe belts-the Xinrong manganese ore, silver and gold mineralization;②the ore in the ductile shear zones of the basement detachment nappe doming-the Hetai gold deposit;③the ore in the ductile shear zones of the ramp rise-the Dagougu gold deposit;④the ore in the nappe folding and thrusiting belts-Dajiangping pyrite deposit; ⑤the ore in the folding and thrusiting belts in the basin-Shijing gold deposit; ⑥the ore in the front stripping extension fault belts-Changkeng gold and silver deposit. The correlation and harmony of the different typical deposits suggest the mineralization and controling ore deposits are governed mainly by the nappe tectonic system besides the strata and lithology.