Abstract:Zhuoma Pb-Zn deposit is located at the Zhongdian area on the western side of the Ganzi-Litang conjunction zone in northwest Yunnan. The ore is hosted in Zhuoma medium-acidic complex porphyry (porphyrite). Previous studies only focused on the ore bodies related to quartz-monzonite porphyry within the complex rock mass, but there is relatively little research on the ore bodies in quartz-diorite porphyrite. Based on mineralogical observations, in-situ trace elements analysis of sphalerite by laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) was carried out. Combined with in-situ sulfur isotope analysis of pyrite, pyrrhotite, and sphalerite, it aims to determine the genetic type and ore-forming temperature of the deposit. The study found that sphalerite in the Zhuoma deposit is characterized relatively enriched Fe, Mn and depleted Cd, Ga, Ge, In and Sn. Among them, Fe, Mn, and Cd enter sphalerite in the form of solid solutions. Copper and Pb exist in the form of microscopic mineral inclusions, and indium exists in the form of micro-minerals combined with cadmium. The δ34S values of sulfides in this deposit ranges between -1.83‰ and +2.30‰. The Zn/Cd ratio of sphalerite ranges from 200 to 322, indicating a close relationship between the source of ore-forming materials and magmatism. The calculation results of the sulfur isotope equilibrium thermometer are from 271℃ to 517℃. The calculation results of the GGIMFis thermometer, the FAS thermometer and the FA6 thermometer for trace elements of sphalerite are 257±17~366±31℃, 234~296℃ and 245~311℃ respectively. Combined with the characteristics of trace elements ratios of sphalerite, it is considered that the precipitation of Pb-Zn ore-forming materials in the Zhuoma deposit occurs in a mesothermal environment. In the sphalerite trace elements ternary diagrams and t-SNE plot, most of the measured points fall within the area of the deposit type related to magmatic hydrothermal fluids. It is considered that the lead-zinc ore body produced on the top of the complex porphyry in the Zhoma deposit is a shallow-seated hydrothermal vein type. This study provides a geological and geochemical basis for understanding the genesis of lead-zinc ores and the exploration direction in the Zhongdian area.