MINERALOGICAL CHARACTERISTICS OF DAHUANGHUA COPPER POLYMETALLIC DEPOSIT IN CERTRAL INNER MONGOLIA

The Dahuanghua Cu-polymetallic deposit is located in the south of Chifeng-Chaoyang Au-polymetallic metallogenic belt. The mineralization is occurred in the contact between Yanshanian syenogranite and Carboniferous Jiujuzi marble with Cu/Fe orebodies formed locally. The skarn minerals are mainly composed of garnet, diopside, tremolite, epidote, chlorite, hornblende and actinolite; while the metal minerals include chalcopyrite, chalcocite, tetrahedrite, bornite, covellite and oxidized secondary minerals such as azurite, malachite and limonite. The wall rock alteration is intensive, presenting a clear zonation:strongly-altered tremolite-actinolite zone, strong tremolite-diopside alteration zone, and weakly-altered marble zone outwards from the contact zone. The metallic element association of Cu-Pb-Zn-Au-Ag is obvious. This Cu-polymetallic deposit was formed in the late period of Middle Jurassic and related to the intrusion of syenogranite, which is consistent with the diagenetic-metallogenic age of Au-polymetallic deposits in Chaoyang-Chifeng area.