Abstract: | The concentration of minerals in the crust forms a continuous distribution between the higher grade reserves mined as ore and the low-grade background mineralization of waste rock. A lognormal distribution could be generated by a mineralization process compatible with the theory of plate tectonics. A computer model of this process is demonstrated. The discussion is extended to other base metals and in particular to the distribution of reduced carbon. Neither base metals nor fossil fuels are ever likely to be exhausted, but they may rise in cost and be superseded by cheaper substitutes. |