Metallogentic Regularity And Prospecting Direction Of Tuoniu Lead-zinc Deposit In Luoping, Yunnan Province

The Tuoniu lead-zinc deposit is located in the southweatern margin of the Yangze block, at the southeastern part of the northeast Yunnan Pb-Zn-Ag polymetallic district, which is an important part of Fule Pb-Zn polymentallic ore concentration. In this paper, based on the results form from previous studies, combining with the field geological survey and comprehensive indoor research, we completed a relatively systematic study in many aspects, such as the geological characteristics of ore deposit, feature of the tectonic, charateristics of ore-forming fluid, geochemical characteristics of soils, stable isotope compositions. Trough the comprehensive research on strata, structure, magmatic rocks and ore-forming relations, deposit genetic model is built; at the same time, we summarized the metallogenic regularities of Tuoniu lead-zinc deposit, which provides a theoretical basis for prospecting work in the next time. The main points are described as follows:(1)Tuoniu lead-zinc deposit was located in the northwest edge of Fule lead-zinc polymetallic deposit. The two deposits belong to the same metallogenic system; both were controlled by interlayer faults that exist in upper Yangxin Formation of Permian. It belongs to Mississippi Valley-type lead-zinc deposit. The layered and lenticular orebody hosted in core of near ns-trending Tuoniu-Duza anticline.(2)The research of fluid inclusions suggested that homogenization temperature of fluid inclusions mainly concentrated in between 114~ 264℃, the salinity and density of ore-forming fluid are mainly 2.1~15.3% and 0.88~0.98g/cm3 respectively, the depth can be determined as 0.47 to 0.95 through calculation. Research shows that Tuoniu lead-zinc deposit is a middle-low temperature, low-shallow, low salinity and middle density deposit.(3)The characteristics of major and trace element shows that the content of Cd, Cu, In, Co and Zn were positive correlation in the ore. The feature of Ga/In reveal sedimentary-reworked type. The surrounding rock generated in the Marine environment, which enrich Cd, Zn, Pb, Bi especially but deplete Ba, Zr, Ce, Li, Rb, Nb.(4)In this paper, we analysed the date of soil geochemistry, determined threshold of anomaly by iterative method and compiled the geochemical anomaly map. The associations of indicator elements were determined by R clustering analysis. The Zn-Pb-Cd combination anomalies were complied and evaluated. Geologic feature anastomosed with Zn-Pb-Cd comnination anomalies of obvious zoning and high concentration.(5)Combined with the previous research on stable isotope, we discussed sources of ore-forming materials, established preliminary metallogenic model and pointed out the prospecting direction.