Re-Os ISOTOPIC DATING OF MOLYBDENITES FROM THE YINGWULING POLYMETALLIC DEPOSIT IN GUANGDONG PROVINCE AND ITS GEOLOGICAL SIGNIFICANCE

Six molybdenite samples are selected from the Yingwuling copper polymetallic deposit to perform the Re-Os dating.It yielded weighted average model ages of 82.96Ma to 84.75Ma, with a narrow range variation.It was showed that the Re-Os dating of one sample collected from skarn-type ore yielded a model age of 82.96Ma±1.2Ma,and five molybdenite samples collected from quartz-vein-type ore yielded model ages ranging from 83.78Ma to 84.75Ma,with an average of 84.08Ma±0.54Ma,and give an isochron age of 83.0Ma±1.7Ma.Evidently,model ages are compatible with isochron age in the error within the allowable range,so it constrains the absolute age of Yingwuling copper polymetallic deposit in 82.96Ma～84.75Ma,namely,the Late Cretaceous is the main time for the formation of ore.The molybdenites from Yingwuling copper polymetallic deposit have a low content of Re,indicating a crustal source for ore-forming materials.It was considered that the deposit formed in the Late Yanshanian lithospheric extensional and thinning environment.