The geochemistry and physical volcanology of the East Lake ultramafic zone, Cape Smith belt, northern Québec /

The East Lake Zone is located within the Raglan horizon of the Cape Smith Foldbelt and hosts an ultramafic dyke/sill complex. The ultramafic units intrude both Raglan horizon siltstone as well as volcanic and volcaniclastic rocks of the Povungnituk Group. Magnesium, silica and chromium variation along with analyses of fresh olivine grains from the East Lake Zone indicate the ultramafic rocks were formed by olivine and chromite accumulation in a magma containing 11--13 wt % MgO. Rare Earth Element profiles of intrusive margins and some Chukotat Group pyroxene-phyric basalts show Light Rare Earth Element enrichment consistent with contamination by Raglan siltstone, however the enrichment occurs stratigraphically below the siltstone, reducing the likelihood of contamination having occurred locally. Sulphur concentrations and olivine nickel contents indicate that minor amounts of sulphide liquid (