Collaborative Research: Testing the hypothesis that iron oxide - copper - gold (IOCG) deposits and iron oxide - apatite (IOA) deposits evolve as parts of the same mineral system

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The sustainability of the human race depends on finding the natural resources necessary to maintain the built infrastructure of the developed world and to build capacity in developing countries. Metals such as iron, copper and gold are among the most important natural resources used by society as they are embedded throughout our built environment. Iron is used to make steel. Copper is used to generate electricity, and copper and gold are used to move electrical current through all electronic products including smart phones, computers, televisions, electric vehicles, airplanes and all medical devices. Two of the most important sources of iron, copper, and gold are mineral deposits known as iron oxide-copper-gold and iron oxide-apatite deposits. Geologists do not yet fully understand the genesis of these mineral deposit types. The lack of a genetic model limits our ability to find new deposits that are necessary to satisfy growing demand for these metals. In this study, we will investigate the formation of both deposit types in Chile and use the results to improve our understanding of a general recipe that can be used to predict the location of undiscovered deposits. The project involves underrepresented graduate and undergraduate students at the University of Michigan and Juniata College and will build new collaborations with the mining industry and academic partners in Chile. The science team will also participate in educational capacity building in West Africa each year. Iron oxide - copper -gold (IOCG) and iron oxide - apatite (IOA) deposits are two of the most controversial ore deposit types in economic geology. Despite having been mined for at least hundreds of years, there is no consensus for how the deposits formed. Despite clear time-space relationships among IOCG and IOA deposits in many districts worldwide, there is no consensus that the deposit types are genetically related. Despite clear time-space relationships with igneous activity, there is no consensus that either deposit type is genetically linked to silicate magma. There is consensus that IOCG deposits formed by purely hydrothermal processes, but the source of the ore fluid(s) is debated. There is no consensus for the formation of IOA deposits, with two very different genetic models proposed: 1) liquid immiscibility, a purely igneous process; and 2) a hydrothermal model that invokes basinal or magmatic brines. The most controversy centers on whether or not the two deposit types are genetically related, wherein a continuum is hypothesized to exist from shallow-level S-Cu-Au-Fe-rich IOCG mineralization that transitions to deeper S-Cu-Au-poor, Fe-rich IOA mineralization. In this study, we will investigate mineralization in the world-class Candelaria IOCG deposit and surrounding Punta del Cobre district in the Chilean iron belt where access to deep (1,000m) exploration drill core will allow us to test the hypothesis that these seemingly separate ore deposit types evolve from the same mineralizing fluid. This project has the potential to significantly change our understanding of IOCG and IOA deposits and has transformative implications for exploration strategies for these deposit types, which are increasingly important strategic sources of their namesake metals as well as rare earth elements (REE), U, P, V, Ag, Co, Bi and Nb, all of which make our built environment - education, medicine, transportation - possible. The project involves underrepresented graduate and undergraduate students at the University of Michigan and Juniata College and will build new collaborations with the mining industry and academic partners in Chile. The science team will also participate in educational capacity building in West Africa each year.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.