摘要
The Jiadanggen porphyry copper deposit was discovered in recent years,but its research is very insufficient.This paper mainly deals with the homogenization temperature of fluid inclusions and the evolution tendency of ore-forming fluid.The fluid inclusions in the pluton and quartz veins are characterized by abundantly daughter minerals-bearing inclusions in which daughter minerals composed of halite,sylvite,gypsum,chalcopyrite,pyrite and hematite.The presence of gypsum and hematite imply oxidation environment at the early stage of magmatic crystallization.The microthermometric analysis of inclusions reveals that the metallogenic fluid consists of both high-temperature,hypersaline fluids and medium-low temperature,low salinity ones.High temperature,hypersaline fluids with temperature of over 440℃,salinity of 30%~82%,and average salinity of 47.3%~67.5% directly resulted from the fluid exsolution from a shallow crystallizing melt at the final stage.The medium-low temperature and low salinity fluid with temperature concentrated in 220~360℃ and salinity lower than 20% was mainly derived from meteoric water,probably mixed with later-stage magmatic hydrothermal fluids.This paper explains the importance of fluid mixing in the ore-forming and unloading process on the basis of the hydrogen and oxygen isotopic composition.The temperature of veined quartz is between 280℃ and 440℃,and the temperature of beresitization is between 240℃ and 340℃,which are the main temperature intervals of mineral precipitation.