GEOLOGICAL FEATURES AND GENESIS OF MACHANGQIN Cu-Mo-Au DEPOSIT RELATED TO THE RICH-ALKALI MAGMATIC ROCK,YUNNAN PROVINCE

The Machangqin Cu-Mo-Au deposit is a type deposit related to the Himalayan epoch rich-alkali intrusive rock. There are several obviously alteration zones in the ore district. The occurrence of orebodies or ore veins had intimate relationships with the rich-alkali rock-body (vein) in space-time and genesis. Based on the gold content in different type rocks, isotope and REE, it is concluded that the origin of the gold and fluid was not from the rich-alkali rocks, but mainly from the depth of the Earth or may be from mantle or the mixing zone of mantle and lower crust. The relationship between magmatic evolution and gold mineralization was discussed.