A Study of Wall-rock Alteration in the Zhongdian Pulang Porphyry Copper Deposit

The Pulang porphyry copper deposit discovered recently is an important copper deposit.On the basis of collection of a large number of field geological data,comprehensive analyses in laboratories,and combination of the results of drilling,physical and geochemical explorations,and remote sensing technology,our preliminary conclusion is that the hydrothermal alteration of India Support phase Pulang porphyry copper deposit,which has the surface-type alteration features of silicified core,potassic silicification zone,sericite rock band,propylite band,and angle rock-oriented band arranging regularly from core to out surface,is a result of Multi-periods and multi-phases construction hydrothermal events.The potassium-based silicification and sericite alteration zones were found to have close connection with the copper deposit;the alteration has effects on the rock(ore) structure which controls the contents of main oxides of rocks and the grade changes of the Cu deposit.Meanwhile,the physical-geochemical anomalies caused by mineralization and alteration showed very good correlation with the anomalies of remote sensing.The anomalies,which have great significance in searching and exploring of the same type deposit in the Zhongdian area,are the direct indicators for ore exploration and the guider for mine engineering layout.