Metallogenesis Of The Giant Luziyuan Pb-Zn Polymetallic Deposit In The Baoshan Block,Yunnan Province, SW China

Baoshan block which under goes compositely orogenic and collisional orogenesis process of Paleozoic and mesozoic is located at the south of the Sanjiang tethyan orogenic belt.Active crustal movement makes the zone having superior minerogenetic conditions. It form a large-scale Skarn type lead and zinc polymetallic ore deposit. And Luziyuan is a typical example. Luziyuan is located at the south plunging crown of the Zhenkang anticline that is at the south of the block. Ore body which is hosted by marbleization-limestone of Upper Cambrian is in vein-like,stratford and rotelliform structures. And it is controlled by NE fault.There are strong wall rock alteration. It mainly include skarnization, choritization, silicification, pyritization, marbleization, ect. Ore minerals are manlygalena, sphalerite, chalcopyrite, magnetite, ect. Ore structure are dominated by disseminate, banding and nervation.The texture of ores are mostly metasomatic texture, idiomorphic granular texture, intersertal texture.Fluid inclusions have wide temperature ranges. And They are different instage of mineralization. The homogenization temperature of magnetite’s mineralization stage is over 600℃; the Pb-Zn sulfide stage is 106℃~330℃. And the formation of lead-zinc orebody comes through meso-low temperature stage of 100~240℃ and meso-high temperaturestage of 240~300℃. Based on the sequence of mineral formation and mineralization in space distribution, it believe that hydrothermal solution’s temperature change from high to meso-low with the mineralizationfollowing the mineralization proceeding and the migration upward of ore-forming hydrothermal solution. It causes that metals illuviate that is controlled by temperature. The precipitation ore-forming materials is mainly affected by temperature.Electron microprobe analyses show that the garnet is mainly iron and calcium-calcium aluminum garnet series, zonation, reflecting the which is formed through the early diffusion metasomatism and late infiltration metasomatism; The Mn/Fe ratio of pyroxene mostly higher than 0.1, and the Pb-Zn mineralization in leading line; amphiboles belong to calcic amphibole series, actinolite, reflecting the calcareous skarn characteristics; Amphiboles belong to calcic amphiboles series, actinolite, reflects the calcareous skarn characteristics.Galena, sphalerite and chalcopyrite δ34S values vary from +9.10 to +14.89 per thousand between, sulfur isotope values decreased with the increase of the depth of, in mining formation without sulfate minerals(Cambrian seawater δ34S per thousand lower limit to +15%), the sulfur isotope composition than(+3 per 1000) and granitic magmatism related to the average sulfur isotopes in sulfides, the inference is due to away from the rock of ore-forming fluid oxygen fugacity due to reduced, the sulfur of the metallogenic system mainly came from the magma.In summary, zhenkang Luziyuan Pb-Zn deposit in Cambrian carbonate strata of ore, NE trending faults of diversion and guide ore and deep concealed acidic rock heating and metallogenetic elements, typical silicon card rock type, lead, zinc, iron and polymetallic deposit.