"Mineralogy and petrology of carbonatites, alkaline rocks and kimberlites"

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The objectives of the proposed research are to understand the origin and evolution of alkaline rocks, carbonatites and kimberlites, together with their associated strategic metal economic mineral deposits. Alkaline and peralkaline syenites are host to Zr, Ti, rare earth element (REE), and P mineralization, carbonates host REE, Ti, Fe, Th, P, F and Nb deposits, and kimberlites are a source of diamond. Although alkaline rocks are of small volume relative to common silicate rocks their parental magmas are typically derived from greater depths in the Earth's upper mantle than those of such rocks, and investigation of their mineralogy and geochemistry provides insights into the metasomatic process occurring in the deeper parts of the lithospheric mantle and the asthenosphere. The research involves a combination of laboratory and experimental work with minor field work. Laboratory work uses electron beam methods (BSE-petrography, energy dispersive X-ray spectrometry, SEM, CL etc) and X-ray diffraction (including Rietveld methods) for quantitative analysis of minerals and their parageneses. Both secondary ion mass spectrometry and laser ablation inductively coupled mass spectrometry are used for in-situ trace and isotopic studies of minerals and melt inclusions. Experimental work includes studies of synthetic analogs of carbonatite magmas at diverse pressures and temperatures using rapid-quench hydrothermal methods, and low temperature hydrothermal experiments using Parr reaction vessels to investigate the decomposition of some rare metal bearing minerals. The outcomes of the work will be a better understanding of the processes which lead to the formation of strategic metal ore deposits. This is of use in prospecting for and evaluation of such ore deposits.