Synthesis of gold compositional data from petrography and detrital gold particles to characterize complex lode gold mineralization

Determining the contribution of individual episodes of mineralisation to the overall metal endowment of a gold deposit may be challenging, especially where veins are complex. We have applied a novel approach to address this problem which utilizes the variance of gold alloy compositions with environment of mineral precipitation. Studies at Curraghinalt (N. Ireland) and Cononish (Scotland) have linked gold compositions to paragenetic stage through classical petrography, and then correlated these compositional ranges to those observed in populations of detrital gold particles derived from erosion of the whole orebody. In this way the gold compositions which relate to the most important phase of mineralisation may be identified. The approach may, in some cases, be limited by the particle size ranges of gold, but can offer an efficient route to targeting the most important ore type and underpin further studies which develop deposit models.