From mantle to crust and exosphere in volcanic arcs

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This research program is directed at understanding the formation and evolution of mantle-derived magmas and lithosphere in settings where two tectonic plates collide (arcs or convergent margins). The research focuses on the partition of fluid and metals between mantle, crust and atmosphere during the egress of magmas from their mantle source regions to eruptions in arc volcanoes where they degas into the atmosphere. The research effort seeks to understand the distribution and geochemical behaviour of key metals (Fe, Cu, Re, As, Sb, In, Sn, W) during the ascent, emplacement and cooling of arc magma, and is underpinned by systematic high pressure-temperature experimentation on: (a) mantle melting as a function of oxygen fugacity (fO2), and (b) fluid/melt/crystal partitioning in primitive arc-derived magmas. Some of the experimental data are compared with an ongoing field study of mid-upper crustal igneous rocks in Jurassic-aged arc crust exposed in oblique section on Vancouver Island, B.C.