Characteristics of ore-forming fluids of the Baguamiao super-large gold deposit, Shanxi, China

摘要

The Baguamiao gold deposit is located in Feng county, Shanxi province. The host formation is the Xinghongpu group of upper Devonian, and the host rock is a set of low-grade metamorphic fine grain clastic rock and pelite, including a set of banded rocks caused by hydrothermal sedimentation. A close relationship between the hydrothermal sedimentary rock series and gold mineralization indicates that the Baguamiao gold deposit belongs to a hydrothennal sedimentary (reformation) type deposit. The Baguamiao gold deposit is one of the largest gold deposits discovered so far within the Devonian sediments in the Qinling orogenic belt with a cumulated Au reserve of up to 117.3 ton, and hence holds a great promise of becoming a super-large deposit.rnGold exists mainly in intergranular form, and the major Gold-Carrying minerals are quartz, pyrrhotite and pyrite which are mainly embedded in 1～10cm wide quartz veins. The gold ore is composed of auriferous quartz and vein-side altered rock, both of them are essential.