Mineralogy, petrology and isotope systematics of Proterozoic continental rift-related alkaline magmatism, Northwestern Ontario, Canada

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Niobium and rare earth element (REE) deposits are formed from highly differentiated magmatic fluids, such as pegmatites, carbonatites, and some peralkaline igneous rocks. Exploration of carbonatite and alkaline complexes across North America is increasing due to the demand of REEs for technological applications in Nd-magnets and diverse electronic components, and Nb for steel alloys. Each Nb- and REE deposit is unique, commonly presenting a variety of Nb- and REE minerals. Current exploration methods are often based on bulk rock analysis. This method is inadequate due to the compositional variation of Nb- and REE-bearing minerals in carbonatites and related alkaline rocks. It is important to understand the mineralogy of each of the deposits.***This program is an integrated mineralogical and geochemical study of carbonatites and related alkaline rocks from Northwestern Ontario that are part of active advanced exploration programs for Nb- and REEs. It will involve in-situ mineralogical characterization (and chemical analysis of minerals), petrological investigations and isotopic (Nd-Sr-Hf-Pb) studies of tracer minerals occurring in the deposits. Two Northwestern Ontario Nb- and REE carbonatite intrusions, the Prairie Lake carbonatite complex, and the Chipman Lake carbonatite dikes and fenites), and two Nb-, REE-hosted multiphase alkaline intrusions (the Coldwell and Killala alkaline complexes) will be involved in this study. All intrusions share an important relationship to the Proterozoic Keweenawan Midcontinental rifting event. Understanding the unique mineralogy and isotopic variation in this geologically complex area will provide important insights into the source of the magma systems and the emplacement of the complexes during the large-scale continental rifting event. This is both beneficial to the exploration industry, and research into the Proterozoic Keweenawan Midcontinental rifting events, where little is understood with regards to the genetic relationship of the carbonatitic and alkaline complexes to the rifting event.**