Implications of the structural setting, magma-wallrock interaction and postemplacement evolution of postorogenic carbonatites for their rare-metal (REE, Nb, Zr, U) potential

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Carbonatites and genetically related rocks are an economically important source of rare metals. In recent years, it has been increasingly recognized that carbonatites may have multiple origins and show fundamental differences specific to their tectonic setting and mantle sources. These relations between the petrogenesis and geochemistry of carbonatites have not been systematically studied to date. Although it has been recognized that some carbonatites are linked to orogenic processes, neither the causes nor mineral potential of this magmatism are presently understood. Other inadequately studied aspects of carbonatite petrology are the effect of magma-wallrock interaction on the transport and sequestration of rare metals (rare-earth elements, Nb, Ta, Zr and U), and the impact of postemplacement processes on the geometry and composition of ore bodies hosted by carbonatites. The proposed research program will address these existing knowledge gaps in an attempt to identify the principal factors that contribute to the development of recoverable economic concentrations of rare metals in carbonatites situated in orogenic settings. The novelty of the proposed program in that it will involve a systematic study of carbonatites from orogenic systems of different age and their petrogenetic and metallogenic analysis in a tectonic and structural context. The program will build on applicant's extensive experience with these rocks and his ongoing collaboration with scientists in Canada, Russia, China, Morocco and the European Union. This research will include a large training component and will be based on a multi-analytical approach to ensure that different styles of mineralization can be interpreted in the context of carbonatite evolution. The three major outcomes of this work will be: (1) an improved understanding of the sources and processes responsible for the formation of postorogenic carbonatites; (2) refined exploration criteria for ore deposits hosted by these rocks, and (3) training of highly qualified personnel with a know-how in rare-metal exploration and practical knowledge of field and instrumental techniques. The University of Manitoba has unique instrumental capabilities for providing this type of training.