Regional metallogenetic geochemical distribution models and prospecting prediction of copper in China

More than 6200thousand square kilometers of regional geochemical surveys at a scale of 1∶200000or 1∶250000have been carried out in China,covering most of the feasible areas in the mainland.Enormous basic high quality geochemical data and tens of thousands of geochemical anomalies obtained have played a huge role in geological prospecting;nevertheless,further development and utilization on these data is still an important topic at present.Based on the copper geochemical map of China at the scale of 1∶5000000,which was compiled using the regional geochemical survey data with the scale of 1∶200000,it is indicated that the copper geochemical background of different tectonic units is of great variety.The Cu geochemical background values are significantly diverse from each other for various geochemical landscapes,showing the highest-level in Karst landscape but the lowest in Forest landscape.The distinctions between the dimension and intensity of regional anomalies under different types of landscapes,metallogenesis and outcrop conditions are significantly evident.Two regional metalogenetic geochemical patterns of copper in China can be summarized into two cases,one is that the Cu mineralization is related to the geochemical province while the second is that there is no evident relationship between Cu mineralization and the geochemical province.Moreover,in high and low or very low Cu background areas the distribution of Cu anomalies are different,and the regional metallogenic geochemical characteristics of Cu can be differ obviously.In the mainland some 79Cu geochemical provinces and one geochemical domain have been delineated and 20Cu ore prospecting areas are divided on the basis of the geochemical provinces,tectonic divisions and the distribution as well as the geological background of known ore deposits.