MINERALIZER CONSTRAINT ON GOLD MINERALIZATION OF AILAOSHAN GOLD BELT

After determining that sulfur is the main mineralizer of ore-forming f luid of Ailaoshan gold mineralization belt in west Yunnan Province of China, the S, He and Ar isotope compositions and geological events rel ated to gold mineralization are studied. It is revealed that the ore-f orming fluid of the belt is a mixture of high temperature S-rich deep- seated fluid and low-temperature S-depleted meteoric groundwater. That the gold mineralization occurred in early Himalayan period resulted d ominantly from the mantle degassing which was associated with the trus t extension at that time. The forming and evolving process of ore-form ing fluid can be determined as: S-rich deep-seated fluid ascended and added to S-depleted meteogenic fluid cycling in shallow fracture syste ms of the belt in early Himalayan period -->the S-depleted meteogenic fluid converted to the mixing fluid containing sufficient S-->gold in surrounding rocks was extracted by the mixing fluid, and then precipit ated at a suitable place to form the gold deposits.