Abstract
In order to assess Chinese gold resources, more than 1600 deposits of the primary and placer types have been statistically analyzed. The deposits are classified into three independent groups and two summarized groups: primary-main (Pm), primary-accessory (Pa), placer (S), primary (P = Pm + Pa) and all data (T = P + S). Gold metal amount shows lognormal distribution in each of the groups. Grade of each of Groups Pm and Pa shows a single population, but that of Group S two populations. The correlation coefficients among grades, metal amounts and tonnages indicate that metal amounts of deposits largely depend on tonnage and scarcely on grades. The grade-cumulative tonnage relation of every group is approximated by the combination of two or three exponential functions. The critical grades of Groups Pm, Pa, and S are 2.8, 0.20 and 0.10 g/t (or g/m3), respectively. These values suggest that the mines with low grades are operated at the critical condition.
