Mineralization-alteration zoning regularity and structural ore-controlling role in the Huize super-large sized Ge-Ag-rich Pb-Zn deposit, Yunnan Province

The Huize super-large sized Ge-Ag-rich Zn-Pb deposit is a typical deposit in the Sichuan-Yunnan-Guizhou lead-zinc polymetallic ore-forming area. On the basis of enormous field survey and tunnel measurements and through studies of petrology and geochemistry of ore-bearing dolomite, the authors investigated zonation regularity of mineralization and alteration and structural ore-controlling role, and the results show that ore-bearing dolomite was formed by dolomitization in the ore-forming process, characterized genetically by typical hydrothermal alteration. Its genetic type differs from that of fine-grained dolomite and dolomitic limestone in the Baizuo Formation. According to the mineral compositions of ores and altered wall rocks, the degree of mineralization and alteration and the distribution characteristics, the zoning regularity of mineralization and alteration has been revealed:from the orebody to the wall rock, there exists the zoning of Zn-Pb ores and Zn-Pb mineralized pyrite zone→Zn-Pb and pyrite-mineralized coarse-grained dolomite zone→gray coarse-grained dolomite zone, beige coarse-grained dolomite zone, flesh red coarse-grained dolomite zone, net veined dolomitized limestone zone, and weakly dolomitized limestone zone. Mineralization and alteration zoning is obviously controlled by interlayer faults on the upper wall of the thrust-fold structures (Kuangshanchang, Qilingchang, Yinchangpo oblique faults and its derivatives folds). On such a basis, the mineralization structure of ore -forming structure, altered dolomite and Zn-Pb orebody has been established. The results obtained by the authors not only enrich the metallogenic theory of the HZT-type Zn-Pb deposits but also have important practical significance for comprehensive geological study of the resources crisis mines in the northeastern Yunnan ore concentration area and the Sichuan -Yunnan -Guizhou metallogenic area.