GEOLOGY AND METALLOGENIC PREDICTION OF PORPHYRY COPPER DEPOSIT IN NANMU AREA, NORTHERN DAXINGANLING MOUNTAINS

Located in the Linxi-Zhalantun polymetallic metallogenic belt in central-northern Daxinganling Mountains, Nanmu volcanic basin is the intersection between northern continental margin of North China Plate and southeast continental margin accretion zone of Siberian Plate. The intrusive rocks are outcropped as stocks and dikes, lithologically dominated by granite porphyry and quartz porphyry. The main alteration types of sericitization, ferritization, silicification and chloritization form multiple alteration zones. The methods of induced polarization (IP) intermediate gradient and IP sounding are used for metal mineral exploration on the basis of 1:50 000 mineral survey and evaluation. The results show that the low-resistivity and high-polarization anomaly zones are in good agreement with the surface dike mineralization sites and soil geochemical anomalies. Four IP anomalies are delineated in the area, with the deep sounding section passing through the JD2 high-polarization, low-middle resistivity layer. It is inferred that there is copper-bearing quartz porphyry body underground. Combined with the geological, geochemical and geophysical characteristics, the existence of porphyries, malachite mineralization and IP anomalies in Nanmu area suggest a certain prospect of deep exploration.