TYPOMORPHIC MINERALOGY AND GOLD-BEARING PROPERTY OF PYRRHOTITE IN HUANGLONG GOLD DEPOSIT, SOUTHERN QINLING MOUNTAINS

The tectonic belt in the south of Southern Qinling Mountains is a large-scale gold ore belt with good metallogenic conditions. The Huanglong gold deposit mainly consists of Jingou ore block, in which pyrrhotite and pyrite are developed. The pyrrhotite ores contain the highest sulfide in the deposit. The pyrrhotite minerals, majorly monoclinic pyrrhotite by component analysis, occur in two statuses, i.e. early-formed disseminated and lumpy type and later vein-type. The deposit belongs to epi-mesothermal type. The trace element analysis results show the pyrrhotite is characterized by rich Co and poor Ni, closely related to gold mineralization. In terms of gold-bearing property, the vein-type pyrrhotite is superior to lumpy type. The finer the vein is, the higher the gold content is. Therefore, veinlet pyrrhotite can serve as an important prospecting indicator in the area.