PREDICTION FOR DEEP ORE PROSPECTING BASED ON THE STRUCTURE OF A PORPHYRY METALLOGENIC SYSTEM:ACCORDING TO FENGSHAN Au-Cu ORE FIELD

Prediction for deep ore prospecting is a frontier and key research in metallogeny and metallogenic prognosis.In the recent years,by researches of ore prospecting in the Fengshan orefield,not only Carlin-type gold deposits and some new clues of ore prospecting are discovered,but also some new insights about mineralization of the ore field are obtained.These discoveries and insights provide new opportunity and condition for establishing perfect three-dimensional model similar to entity of porphyry metallogenic system and prediction for deep ore prospecting.There are skarn Cu-Au,porphyry Cu-Mo,hydrothermal vein-type polymetallic(Au) and Carlin-type deposits in the orefield,they often coexist with Yanshanian granodiorite-porphyry and are porphyry metallogenic series formed by the some metallogenic system.Relaxed nappe structures control Yanshanian magmatism-metallization in the orefield.Porphyry metallogenic system possesses obvious zonations at aspects of ore types and others.According to the zonations,target areas and prospecting methods are chosen,and location of hidden ore bodies is ascertained.Rich and thick Au-Cu ore bodies have been discovered by a validating drill hole.