Evaluating portable Raman spectrometers for use in exploration of pegmatite dikes, Wekusko Lake, Manitoba

Abstract

Pegmatite deposits are an important source of lithium, which increasingly is used in battery technologies. The rare-metal pegmatite dikes of the Green Bay group from the Wekusko Lake pegmatite field in Manitoba offer an excellent opportunity to investigate new exploration techniques for lithium pegmatites. The dikes were mapped and sampled during the summer of 2018, and this work revealed that the pegmatite dikes are deformed and folded. The examination of drill core revealed that the pegmatite dikes exhibit five zones, defined by their minerology and grain size: a border zone, wall zone, intermediate zone, central zone and a core zone. The zones vary in width and all zones are not always present in each pegmatite. The crystal habit of muscovite, feldspar and spodumene vary based on the host zone and muscovite mineral chemistry is being examined as a potential vector for Li mineralization. Columbite-group (CGM) minerals are zoned with respect to Nb and Ta values and primary grains have been selected for U-Pb geochronological studies.