Diamond resorption in kimberlite and mantle

The majority of gem diamonds are mined from kimberlites - the deeply formed volcanic rocks that bringmaterial from the Earth's mantle to the surface. The diamond quality and grade can vary considerably even inneighboring kimberlite pipes. During residence in the mantle and transportation to the Earth's surface inkimberlite magma diamond and other deep mantle minerals undergo partial dissolution and develop resorptionfeatures, which are sensitive to the conditions of the surrounding media. The existing diamond explorationmethods rely on analyses of chemical composition of mantle-derived minerals, which surface morphology canalso be a valuable source of information for predicting diamond grade and quality in kimberlites. We willexamine micro-diamond populations and samples of other mantle-derived minerals (chromite and olivine) froma number of Canadian and Botswana kimberlites aiming to understand which factors of mantle and kimberlitichistory of diamonds play a major role in diamond preservation. Surface dissolution features on diamond andchromite crystals will be characterized using state-of art equipment for surface studies, an Atomic ForceMicroscope. Our research will provide constrain of fluid history of kimberlite magma with different diamondpopulations linking diamond potential to the behavior of volatiles. We will develop an application of surfacefeatures on an abundant and very resistant to weathering mineral, chromite, for diamond exploration that wouldhelp to determine crystallization conditions of kimberlite and their effect on diamond population. We will alsolook into the mantle part of diamond history to use mantle-derived diamond morphology for understanding thecomplex metasomatic history of continental roots underlying kimberlite fields. Our project will use newdevelopments in experimental and imaging studies of diamond dissolution to better explain diamond potentialof the explored kimberlite bodies and develop new methods for ongoing exploration programs.