Past research has focused on constraining the origin and metasomatic history of the subcontinental lithospheric mantle (SCLM) beneath the Slave Craton and the Buffalo Head Terrane in northwestern Canada, using major and trace-element and multi-isotope analyses of peridotitic xenoliths and their constituent phases.
Eclogites and pyroxenites are a minor but important component of the SCLM that may have low (crustal) and high-pressure mantle origins. Again, the compositions of xenolithic eclogites and related rocks are “decrypted” to obtain information on their source(s) and later processes, including subduction-related and during later residence in the SCLM, that led to corruption of primary signatures.
The compositions of accessory phases have proven to be valuable tools. For example, in situ trace-element Re-Os isotope analyses of sulfides have given us constraints on the formation age of the mantle, while the trace-element and Hf isotopic composition of eclogitic rutile has been useful as a dating tool and as a discriminant between subduction-modified and metasomatised eclogites.
My present work explores the usefulness of Li isotope compositions in tracing crustal components and fingerprinting metasomatic agents in the Earth’s mantle using mantle samples from a variety of settings and ages. These data can be combined with radiogenic isotope systems (Sr, Nd, Pb) and other stable isotope systems (O, S) to constrain the compositions of different components in the Earth.