Magmatic assemblages and metasomatic overprints

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In broad terms, I focus on the mineralogy and petrology of crustal rocks, in particular those rocks formed in an extensional tectonic environment. I document what the magma produced, and how an aqueous phase exsolved from the melt or from outside interacts with the just-formed hot rocks as they cool and contract. Evolved igneous rocks like granites, nepheline syenites and carbonatites commonly involve a mixed crust + mantle provenance, which can best be evaluated using isotope geochemistry. The hydrothermal mobility of high-field-strength elements like Ta, Zr and Ti remains a contested area, and requires much more documentation in field-based studies. More basic rocks also bear the hydrothermal imprints, and mobility in those cases may well involve the platinum-group elements, of great economic importance. Field studies will focus on the Bancroft area of Ontario, the classic anorogenic Younger Granites of Nigeria, the granitic pegmatites of the Borborema Province, Brazil, and of Catalunya, Spain, the catazonal rocks of southern Madagascar, and the alkaline rocks of the Monteregian Province of Quebec. The crust also bears the imprint of localized impact-generated melting; a project on the Clearwater Lake craters in northern Quebec will shed light on the remelting of the metamorphic Archean basement and the limestone cover in the area. Many of the research projects address topics at the "cutting edge", about processes that shaped of crust of the Earth. At the same time, they touch on economic aspects, in particular those studies that address the platinum-group elements and the high field-strength elements, and thus have the potential of an impact on the optimization of mineral exploration for those commodities in Canada and elsewhere.