Characteristics of ore minerals for the Changtuxili Ag-Pb-Zn-Mn deposit in the middle-southern segment of Da Hinggan Mountains and its constraints on the genesis of the deposit

The Changtuxili Ag-Pb-Zn-Mn deposit is a newly discovered polymetallic deposit in Xilinhaote-Huolinguole Pb-Zn-Ag-Cu-Mo polymetallic metallogenic subzone of the middle and southern Da Hinggan Mountains polymetallic metallogenic belt in recent years.In order to explore the mineral type, mineral occurrence state, and genesis of the Changtuxili deposit, the occurrence of silver minerals, sulfides and manganese minerals were studied by mineral phase observation and electron probe analysis.The silver minerals in the deposit are freibergite, polybasite, pyrargyrite, which are distributed as separate silver minerals in metal sulfides.The Ag content of freibergite ranges from 8.25% to 13.11%(10.54% on average), and the Cu content of freibergite ranges from 27.65% to 31.43%(29.64% on average).The element X-ray mappings show that Ag is present in freibergite in the form of isomorphism.The silver content of polybasite is relatively high(average 68.99%), mainly distributed in the edge of galena and its fissures, indicating that galena is an important silver-carrying mineral.The black manganese cap is a geological sign for finding Ag-Pb-Zn deposits.Sphalerite belongs to low iron sphalerite, and the content is 0.30%~0.38%, with an average value of 0.33%.Cd has a good correlation with Zn in sphalerite and can be used as a geochemical marker for sphalerite prospecting.Rhodochrosite is the product of late low-temperature quartz-carbonate stage.MnCO₃ is the main mineral component and rhodochrosite belongs to hydrothermal genesis.Manganese oxides are mainly pyrolusite and psilomelane.Pyrolusite shows ring and colloidal structure, and it enriches high-grade Pb and Zn besides Mn.Comprehensive analysis of the mineralogical characteristics and ore geological characteristics of the Changtuxili deposit, which is considered to be a hypothermal hydrothermal Ag-Pb-Zn-Mn polymetallic deposit.