Systematics, development and applications of sulfide mineral geochronology using rhenium-osmium isotopes

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The proposed research is focused on geochronology - the science of determining absolute geological time using radioactive decay. It will develop, test and apply the 187Re-187Os radioactive decay scheme to date sulfide minerals that form in economically-important ore deposits of copper, lead and zinc from Canada and other locations internationally. The research has the potential to develop tools that will revolutionize our understanding of when these ores form, and thereby better identify how these ores form – to identify the causative geological processes and events that formed ore.***Testing the accuracy and reliability of these mineral chronometers is a critical and integral part of the work proposed. Not all minerals yield accurate geological ages, and defining the conditions for which minerals do and don't yield accurate ages is an essential part of the planned research program. Rigorous testing will include two of the most common sulfide minerals; pyrite and chalcopyrite, to evaluate how they behave during episodes of younger thermal disturbance. Copper is a critical metal in modern society, but the origin of some ores of copper formed in sedimentary basins is poorly understood. A second objective will test whether the copper sulfide minerals provide meaningful age information using Re-Os isotopes by firstly undertaking systematic projects, and then applying the knowledge gained to sediment-hosted copper ore deposits to better understand their formation mechanisms and processes. Regional-scale fluid flow in Earth's sedimentary basins forms important metallic ores of zinc and lead, and can contribute to porosity development in petroleum reservoirs, but the underlying causes of fluid flow remain controversial. Proposed research will develop the mineral pyrite as a chronometer to test competing ideas for the geological processes that drive fluid flow in sedimentary basins. ***The derived ages of ore formation will allow a far better understanding of the often complex series of processes required to form these critical resources, and allow geologists to test and evaluate competing hypotheses for ore formation. In turn, this may allow minerals exploration programs to better identify prospective and non-prospective areas of Earth's crust for evaluation of resource potential.**