Abstract for: Modelling the Skinner Thesis: Consequences of a Lognormal or a Bimodal Resource Base Distribution

The copper case is often used as an example in resource depletion studies. Despite these studies, several profound uncertainties remain in the system. One of these uncertainties is the distribution of copper grades in the lithosphere. The Skinner thesis promotes the idea that copper grades may be distributed with a bimodal distribution instead of a lognormal distribution. This paper presents a System Dynamics implementation of both the lognormal and the bimodal distributions. By simulating this model for different demand scenarios, it was demonstrated that in case of a bimodal distribution, a slower degradation of copper grades is to be expected. This is in contrast with the common believe that the bimodal distribution, and the ‘mineralogical barrier’ between the two modes, limit the availability of affordable copper.