Research on the source of Au in Bengnazangbu placer gold deposit,Tibet

Placer gold deposits are wide spreading in the northern Tibetan plateau,but rock gold exploration has no penetration yet.Through detailed research on geological environment,placer gold occurrence horizon,placer gold granularity,shape,composition,and correlative heavy mineral assemblage of Bengnazangbu placer gold deposit that is the largest in northern Tibet,we discover that the placer gold enriched horizon and degree are mutually correlated with the content of cryptocrystalline siliceous concretion or siliceous cement.The research shows that in this gold deposit,gold is from deep Earth,and it was carried out by terrestrial hot spring and then turned into surface supergenesis,and gold was transferred and enriched owning to change of water-chemical environment. This embodies a continuous mineralizational mechanism of endogenous and exogeneous mineralization,which has important significance for recognition of the placer gold mineralization and rock gold exploration sign.