Some New Grasp of the Shuiyindong Gold Deposit in Guizhou Province

The Shuiyindong mine is one of the largest and richest Carlin-type deposit in the Yunnan-Guizhou-Guangxi gold triangle area, whose orebodies occur in the high-porosity bioclastic limestone of the Permian Longtan Fm.. Microscope observations see five kinds of pyrites: framboidal, fine-grained, coarse-grained, bioelastic and banding ones. The framboidal pyrite is of sedimentary genesis, little related with the mineralization. The fine-grained, bioclastic and banding pyrites are of hydrothermal genesis, while the coarse-grained pyrite is of sedimentary and hydrothermal genesis. The coarse-grained euhedral pyrite has a sedimentary-type core that is enclosed by the hydrothermal arsenic pyrite. The backscattered images show that the mainly occurs in the hydrothermal arsenic-rich pyrite. The distribution of pyrites and gold-bearing sulfide suggests that adsorption and electrochemical processes are the possible mechanism for the formation of the Carlin-type deposits.