Abstract

Metals concentrate in fluids and magmas within the Earth’s crust. For example, interaction between magmatic intrusions, fluids and the surrounding rocks causes enrichment of metals such as copper, gold and molybdenum in porphyry style deposits. In these settings, the metals are intimately associated with veins containing minerals such as quartz and calcite. In order to develop predictive models for mineralised systems it is imperative to understand the timing of emplacement of these veins. Dating of hydrothermal veins, however, has proved challenging due to lack of suitable ‘datable’ material. Here we use the newly-developed U-Pb calcite dating technique to test the capabilities of calcite dating for providing robust and critical timing constraints for ore-deposit models using the Yukon in NW Canada as an example. The results represent a significant contribution to tectonic and mineralisation models for the region and explore the role of major strike-slip faults for hosting and facilitating deposition of economic Cu-Au deposits. Furthermore, our results demonstrate the potential for calcite U-Pb dating to provide timing constraints for hydrothermal mineralisation processes in a variety of deposit-type settings.

Please contact James at jac293@cam.ac.uk for Zoom details