Characteristics Of Geophysical And Geochemical Anomalies And Prospecting Criteria Of The Xizhuang Cu Orefield,West Hengshan,Jiangning,Nanjing,Jiangsu Province

The Middle-Lower Yangtze River metallogenic belt is one of the most important metallogenic belts in China.Located at the eastern lower Yangtze fold belt of Yangtze paraplatform,the Nanjing-Lishui area is a part of Fe-Cu polymetallic mineralization belt at the middle-lower reaches of Yangtze River.The West Hengshan ore deposit discussed in this paper is situated in the Nanjing-Wuhu ore district of the Middle-Lower Yangtze River metallogenic belt,between Nanjing-Wuhu volcanic faulted basin and the Maoshan that is the backbone of Nanjing-Zhenjiang reflex arc of Huaiyang epsilon structural system.Therefore,the Huanzidong and Heyeshan Cu-Ag ore deposits,as well as Xizhuang and Fenghuangshan Cu deposits have been the key target studied by geologists in Jiangsu Province.In this paper,for the studied ore area,the geophysical and geochemical anomalies of Xizhuang rock bodies are verified;the petrogeochemistry and pedogeochemistry are studied;the age of the rock bodies are determined,their genetic types,material sources,structural signification and relations with mineralizations are discussed as well.Based on the correlation analysis for the total 193 pieces of collected samples,the major ore-controlling factor is revealed.The elements,such as Zn-Mn,Pb-Ag and Cu-Sb,are well correlated.Based on the collected data,the cluster analysis was carried out for each element.The dendrograms indicated strong correlation between Au andBi,Pb-Zn-Mn-Ag and As are closely related.Au is poorly correlated with other elements.In combination with factor analysis,we considered that the mineralization resulted from the principal ore-controlling factor is the association of(Pb-Mn-Zn-Ag)-As and Au-Cu.An analysis of the 1:5000 IP data of ore-bearing rocks shows low resistivity and high polarization rate.Through the geophysical and geochemical anomaly analysis in combination with the geological characteristics,the authors hold that TR2,TR3 anomalies are the most favorable metallogenic physicochemical positions.2 IP sounding profiles were deployed to carry out the anomaly verification work,and then three drill holes were arranged in the favorable ore-forming places chosen from the anomaly area,which led to the discovery of copper ore mineralized body.According to the geophysical and geochemical anomaly characteristics and metallogenic geological conditions,combined with the validation results of drilling engineering,this paper summarizes the prospecting criteria,and points out that the TR2 anomaly belt should be the next place for engineering validation.