Studies On The Ore Fluid Of Hetaoping And Jinchanghe Deposits In Sanjiang Region,Yunnan Province

Hetaoping lead-zinc and Jinchanghe iron-copper-lead-zinc polymetallic deposits are located in the northern of Wayao town Baoshan city,Yunnan province,and they are of typical polymetallic skarn deposits in the Baoshan block.The main ore-rich terrane are Cambrian stratas in the Hetaoping and Jinchanghe deposits,where folds and fracture structures developed with,but less magmatic rocks exposed.Collected samples in this work are metal sulfides and gangue mineral samples like quartz in Shangchang,Benbu and Huizidong ore block of Hetaoping deposit,and those of 1810,1750 and 1720 heights of Jin-changhe deposit.Detailed microthermometric,laser Raman and HO-isotopic analyses have been made for fluid inclusions of main metallogenic stage.Similar fluid characteristics have been found for the main metallogenic stage of the Hetaoping and Jinchanghe deposits.Fluid incluisons can be divided into pure-liquid,pure-vapor,vapor-liquid and CO₂-bear three-phase inclusions.Their shapes are of oval,negative crystal,square,irregular and so on.Sizes of fluid inclusions are usually around 5-20 ?m,distributed as groups or singles.The microthermometric analysis show that homogenization temperatures and salinities of the vapor-liquid inclusions are relatively low.In the Hetaoping deposit,homogenization temperatures and salinities of inclusions focus on 150-230 ?,three intervals of 1-5,6-13 and 14-17 wt% NaCl.eqv,respectively.In the Jinchanghe deposit,homogenization temperatures and salinities focus on 150-210 ?,1-9 and 10-14 wt% NaCl.eqv.Laser Raman analysis of fluid inclusions in the Hetaoping and Jinchanghe deposits indicate that N2,CH4,CO₂ and H2 O are in the vapor phase and H2 O is the main component of liquid phase.By combining oxygen-isotopic thermometer and isochores of fluid inclusions,the average ore-forming temperatures and pressures are estimated to be 160-210 ? and 16.23-41.81 MPa for the Hetaoping deposit,and 184 ? and 27.87 MPa for the Jinchanghe deposit.Source of ore-forming fluid can be directively obtained from the HO-isotopic compositions in sulfide.On the ?D-?¹⁸O diagram,the HO-isotopic data points are located between the meteoric water line and magmatic water,which suggests that the ore-forming fluid mainly originates from the meteoric water,simultaneously mixing with magmatic water.