Discovery of lead–zinc polymetallic veins and its implications for prospecting in the Sumochaganaobao supergiant fluorite deposit, Inner Mongolia

This paper is the result of mineral exploration engineering.

Objective The Sumochaganaobao supergiant fluorite deposit is considered as the largest single fluorite deposit in the world. In recent years, large–scale polymetallic veins of lead and zinc revealed by tunnel engineering, this indicates that in addition to fluorite ores, the deposit may also have great potential for metal mineralization. Based on the newly discovered lead-zinc polymetallic vein, this paper found out its ore mineral development characteristics, discussed its mineral components, spatial and temporal evolve regulation of the elements and the genetic type of the deposit, which provide a basis for the prediction of deep polymetallic prospecting and provide a reference for the deep polymetallic prospecting of similar fluorite deposits in the region.

Methods Based on the metallogenic conditions of study area and geological characteristics of the veins, combined with mineralogy study and electron probe test, this paper has discussed the characteristics and genesis of polymetallic veins of lead and zinc.

Results The polymetallic veins of lead and zinc are veins, lenticular and irregular. The main ore minerals are sphalerite, galena, pyrite, chalcopyrite, arsenopyrite, and a small amount of bismuth, cassiterite, silverzoisite, etc. The ore structure focus on disseminated, brecciform and reticulated vein, and the mineral structure is mainly euhedral to semi–euhedral granular, skeleton crystal and veinlike, etc. According to the characteristics of vein pattern and the ore mineral combination, combined with electron microprobe analysis, it shows the polymetallic veins by down with sphalerite–pyrite–chalcopyrite–arsenopyrite–galena–silverzoisite low temperature mineral association → galena–sphalerite–pyrite–cassiterite–bismuthinite high mineral assemblage zoning features. With the deepening of mineralization depth, the content of low temperature mineralization elements decreases, while the content of high temperature mineralization elements increases.

Conclusions Features of geological and ore show that the lead–zinc polymetallic veins formed earlier than surrounding fine crystalline fluorite the which in gray, light brown color. According to the ore–body development and mineral characteristics, the lead–zinc polymetallic vein shows magmatic hydrothermal genesis. The stable extension of the veins and the spatial variation of ore–forming elements suggest that there may be large–scale lead–zinc polymetallic veins in the deep of the Su–Cha ore area.