Grant: Discovery Grants Program - Individual

Metallogeny of convergent and collisional plate margins through geological time:*Convergent and collisional tectonic plate margins, where one plate subducts beneath or collides with another, are the only locations where crustal materials are returned to the mantle. These materials include volatiles such as water, sulfur, and chlorine, which are critical for the solubilization and transport of metals in mantle-derived magmas, and which are exsolved again as hydrothermal fluids from those magmas upon emplacement in the upper crust. Porphyry Cu±Mo±Au and epithermal Au±Cu ore deposits are formed where the flow of these fluids is sufficiently focused and voluminous to result in precipitation of ore minerals in economic concentrations. While major advances have been made in recent years relating to ore depositional processes, the underlying magmatic and tectonic processes that give rise to fertile magmas (i.e., magmas with the potential to form ore deposits) are less well understood, and less well integrated into metallogenic models. The objective of this proposal is to draw together and extend research on subduction and collision zone tectonics and magmatism, with a focus on constraining the processes that affect the behaviour of metals. This is a large endeavour, and I will work collaboratively with other researchers with specialist expertise to achieve these goals. Specific areas of research will be: Phanerozoic subduction and post-subduction ore-forming processes at an Earth-system scale; the metallogeny of the lower crustal roots of magmatic arcs, where evidence for deep processing of mantle-derived metals can be observed in rare exposures; and rare Precambrian porphyry deposits that may preserve evidence of changing tectonomagmatic processes over geological time, and their effects on metallogeny.*This research has significance for the exploration and discovery of new resources of Cu, Mo, Au, and other metals, which are critical for the maintenance and growth of modern society. Discovery rates of economic deposits of these metals are falling despite increased exploration expenditures, and the industry is looking for new concepts and better models that can help predict the occurrence of ore deposits, especially in previously overlooked or covered terranes. The regional scope of the proposed research provides fundamental information about the prospectivity of magmas and volcanic arcs, which can be used to develop novel exploration strategies in mature mineral belts, and to prioritize and focus exploration in new regions. Parallel research (not part of this proposal) takes this a step further to also consider the environmental and socioeconomic impacts of mining.