Senior Lecturer

Research

Geoffrey is an igneous petrologist and economic geologist with an interest in general petrological problems and related ore-forming processes; including, kimberlite magma genesis and emplacement, evolution of the sub-cratonic mantle through the study of mantle xenoliths and diamonds, origin of ore deposits in layered intrusions, and evolution of magmatic plumbing-systems on Mars. Kimberlite and mantle related studies are based out of the University of Cape Town making use of the world famous ‘Mantle-room’ collection comprising 1000’s of samples collected over several decades by Prof. John Gurney and colleagues, as well as filed trips to various kimberlite pipe localities in southern Africa and recent project development into West Africa kimberlites. The study of magmatic-systems on Mars was developed during his period as a post-doc at the University of Tennessee (2013-2015) and continues with colleagues in the USA. These studies are based on the petrology of the shergottite meteorites that originate from Mars, which are kindly loaned from the NASA Johnson Space Centre.

Latest Publications

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1. Howarth, G. H., & Nembambula, T. 2021. Petrogenesis of Kaapvaal lamproites (aka orangeites) constrained by the composition of olivine and similarities with kimberlites and other diamondiferous lamproites. Lithos, 406, 106499.
2. Ramsey, S. R., Howarth, G. H., Udry, A., & Gross, J. 2021. Nickel–manganese variability in olivine and Al‐in‐olivine thermometry for olivine‐phyric shergottites. Meteoritics & Planetary Science, 56(8), 1597-1618.
3. Udry, A., Howarth, G. H., Herd, C. D. K., Day, J. M., Lapen, T. J., & Filiberto, J. 2020. What martian meteorites reveal about the interior and surface of Mars. Journal of Geophysical Research: Planets, 125(12), e2020JE006523.
4. Howarth, G. H., & Giuliani, A. 2020. Contrasting types of micaceous kimberlite-lamproite magmatism from the Man Craton (West Africa): New insights from petrography and mineral chemistry. Lithos, 105483.
5. Howarth, G. H., & Büttner, S. H. 2019. New constraints on archetypal South African kimberlite petrogenesis from quenched glass-rich melt inclusions in olivine megacrysts. Gondwana Research. 

Biography

Geoffrey did his undergraduate and postgraduate studies at Rhodes University receiving a PhD in Geology based on a study of Fe-Ti-V oxide formation in the Panzhihua mafic layered intrusion in SW China. He went on to do a post-doctoral research fellowship with Prof. Lawrence Taylor at the University of Tennessee. He then did a second post-doc at UCT from 2015 to 2017. Geoffrey was then appointed as an Assistant Professor at the University of Georgia where he worked for a year before returning to UCT as a Lecturer in the Department of Geological Sciences in 2019.