Abstract:

The Gongding gold-polymetallic deposit of Cangyuan, western  Yunnan occurs in a fracture zone in inner contact of western margin of  the Gengma granite pluton. The ore bodies are simply vein-shaped. Analyses of S and Pb isotopes, and homogenization temperature and composition of fluid inclusions have been conducted. The results show that the ore-forming fluids likely came from meteoritic water mixed with magmatic fluids, and the metals might be extracted from the Proterozoic strata, with some kinds of deep source metallic components carried by magmatic fluids. The homogenization temperature is 217-353 ℃, belonging to intermediate-high temperature hydrothermal deposit. According to the spatial distribution of the ore deposit, wall-rock alteration and the timing of the ore formation, two types of settings could be of great potential for further prospecting. One is the setting where late-Yanshanian intermediate-acidic dikes, especially dioritic dikes, are concentrated; the other is fracture zones within inner contact of the Gengma granite pluton with the Proterozoic Ximeng Formation.

Key words: Gongding of Cangyuan County, Yunnan Province, gold-polymetallic deposit, metallogenetic chara