A study of peridotite xenoliths from Voyageur kimberlite, Slave craton, Canada

Twenty two peridotite xenoliths from the Voyageur kimberlite were studied to characterize the mantle rocks from the northern part of the Slave Province and to provide information regarding their conditions of origin. Major and minor element compositions of the constituent mineral phases were determined using electron microprobe techniques (EPMA) and selected garnet and clinopyroxene grains were analyzed for trace and ultra-trace elements by laser-ablation inductively coupled plasma mass spectroscopy (LA-ICPMS).; The study showed that "depleted" garnets are completely absent. Trace element data suggest pervasive metasomatic enrichment beneath Voyageur and different stages of equilibration of an initial harzburgitic composition with low volume percolating melts. Geothermobarometry results define an array representing equilibration of the Voyageur peridotite xenoliths along a 40mW/m 2 geotherm and a thickness of at least 170km of the subcratonic lithospheric mantle at the time of kimberlite emplacement.