Abstract:
The Wangzhuang gold deposit is a newly discovered deposit in South Qinling in 2021. The ore type is a fine disseminated type. The ore body is controlled by both structure and stratum, and it is produced in an interlayer fracture zone. The main metallic minerals of the Wangzhuang gold deposit are arsenopyrite and pyrite, According to microscopic identification and electron probe analysis, the gold is mainly invisible gold in arsenopyrite and arsenian pyrite, and no natural gold is found. Based on the field work, the Wangzhuang gold deposit can be divided into four ore-forming stages: I, the early ore-forming-stage of pyrite quartz veins; II, the main stage of arsenopyrite, pyrite, and quartz veins; III, quartz veins with a small amount of polymetallic sulfide stage; IV, late carbonate stage. The pyrite in different stages has different characteristics of trace elements: stage I pyrite is poor in As and Au, rich in Fe and S; the pyrite of stage II and III are characterized by high As, Au, low S and Fe, and there is a positive correlation between Au and As in pyrite of this stage. The average Co/Ni ratio of pyrite in the Wangzhuang gold deposit is 2.03 and the median is 1.34, indicating that pyrite formed in the ore-forming master stage has the addition of magmatic fluid. In addition, there are two gold-bearing areas in the range of Co/Ni < 1 and 1.2 < Co/Ni < 2.5, indicating that there may be mineralization of two different fluids. Based on the geological and mineral fabric characteristics of the deposit, it is preliminarily concluded that there is multi-stage mineralization in the Wangzhuang gold deposit.