Identifying the Median Grade-Tonnage Curve from the Global Database of VMS Copper Mining Projects

This paper presents a statistical analysis of the global database of Volcanogenic Massive Sulphide (VMS) mineral deposits. The paper shows the joint and partial probability distributions for copper equivalent grade and total tonnage based on current metals prices for copper, zinc, lead, and gold. The article develops a new method using the joint distribution to identify the set of quantile values for grade and tonnage that have approximately 50% probability; this set of quantile values represents the median grade-tonnage curve for VMS deposits around the world. The article also shows how to analyze individual projects in comparison with the global database. For example, the size of the Shamlugskoe mine in Armenia is ranked according to the global database. For another example, a model of the exploration project called Mount Sicker is presented and compared to nearby projects that are in the global database.