Dr Geoffrey Howarth

Department of Geological Sciences, University of Cape Town
Website: https://ghhowarth.wixsite.com/geoffrey-howarth
Research keyword: Kimberlites; diamonds; large igneous provinces

Dr Geoffrey Howarth is currently a Lecturer at the University of Cape Town. As an igneous petrologist, he is interested in the evolution of ancient (~3 billion-year old) cratonic regions through the study of kimberlites, mantle xenoliths, diamonds, and continental flood basalts (CFBs). In recent years, he has applied his knowledge as a terrestrial petrologist to the study of Mars using meteorites / of Martian meteorites. Through this combined terrestrial and Martian research, he aims to tackle big-picture questions involving plume volcanism and the mantle evolution of both Earth and Mars. Geoff completed his PhD in Geology at Rhodes University under the supervision of Prof. Steve Prevec, following which he held two consecutive post-doctoral fellowships / research positions? at the University of Tennessee, Knoxville, and at the University of Cape Town, respectively. In 2018 he held a position as Assistant Professor at the University of Georgia, Athens, where he taught… Geoff was awarded a ‘P’ (for Prestigious) research rating from the National Research Foundation, South Africa, in 2018. He returned to South Africa in 2019 to take up his current Lectureship at UCT, and in the same year was selected as part of the UCT Vice Chancellor’s 2030 Leadership Project. He teaches courses and runs field trips related to economic geology, and leads his own research group related to terrestrial, planetary, and economic geology.  

  1. Relevant Publications
    1. 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.
    2. Howarth, G. H., & Gross, J. 2019. Diffusion-controlled and concentric growth zoning revealed by phosphorous in olivine from rapidly ascending kimberlite magma, Benfontein, South Africa. Geochimica et Cosmochimica Acta, 266, 292-306.
    3. Howarth, G. H., Moore, A. E., Harris, C., van der Meer, Q. H., & le Roux, P. 2019. Crustal versus mantle origin of carbonate xenoliths from Kimberley region kimberlites using CO-Sr-Nd-Pb isotopes and trace element abundances. Geochimica et Cosmochimica Acta, 266, 258-273. 
    4. 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, 68, 116-126.
    5. Abersteiner, A., Kamenetsky, V. S., Goemann, K., Giuliani, A., Howarth, G. H., Castillo-Oliver, M., … & Cherry, A. 2019. Composition and emplacement of the Benfontein kimberlite sill complex (Kimberley, South Africa): Textural, petrographic and melt inclusion constraints. Lithos, 324, 297-314.
    6. Howarth, G. H. 2018. Olivine megacryst chemistry, Monastery kimberlite: Constraints on the mineralogy of the HIMU mantle reservoir in southern Africa. Lithos 314-315, 658-668.
    7. Howarth, G. H., Day, J. M., Pernet-Fisher, J. F., Goodrich, C. A., Pearson, D. G., Luo, Y., Ryabov, V. V., & Taylor, L. A. 2017. Precious metal enrichment at low-redox in terrestrial native Fe-bearing basalts investigated using laser-ablation ICP-MS. Geochimica et Cosmochimica Acta, 203, 343-363.
    8. Howarth, G. H. & Taylor, L. A. 2016. Multi-stage kimberlite evolution tracked in zoned olivine from the Benfontein sill, South Africa. Lithos, 262, 384-397.
    9. Jean, M. M., Taylor, L. A., Howarth, G. H., Peslier, A. H., Fedele, L., Bodnar, R. J., Y Guan, LS Doucet, DA Ionov, AM Logvinova, AV Golovin, & Sobolev, N.V. 2016. Olivine inclusions in Siberian diamonds and mantle xenoliths: Contrasting water and trace-element contents. Lithos265, 31-41.
    10. Taylor, L. A., Logvinova, A. M., Howarth, G. H., Liu, Y., Peslier, A. H., Rossman, G. R., Guan, Y., Chen, Y., & Sobolev, N. V. 2016. Low water contents in diamond mineral inclusions: Proto-genetic origin in a dry cratonic lithosphere. Earth and Planetary Science Letters, 433, 125-132.
    11. Howarth, G. H., Sobolev, N. V., Pernet-Fisher, J. F., Ketcham, R. A., Maisano, J. A., Pokhilenko, L. N., Taylor, D., & Taylor, L. A. 2015a. 3-D X-ray tomography of diamondiferous mantle eclogite xenoliths, Siberia: A review. Journal of Asian Earth Sciences, 101, 39-67.
    12. Logvinova, A. M., Taylor, L. A., Fedorova, E. N., Yelisseyev, A. P., Wirth, R., Howarth, G.H, Reutsky, V.N., & Sobolev, N. V. 2015. A unique diamondiferous peridotite xenolith from the Udachnaya kimberlite pipe, Yakutia: role of subduction in diamond formation. Russian Geology and Geophysics, 56(1), 306-320.
    13. Pernet-Fisher, J. F., Howarth, G. H., Pearson, D. G., Woodland, S., Barry, P. H., Pokhilenko, N. P., Pokhilenko, L.N. , Agashev, A.M., & Taylor, L. A. 2015. Plume impingement on the Siberian SCLM: Evidence from Re–Os isotope systematics. Lithos, 218, 141-154.
    14. Barry, P. H., Hilton, D. R., Day, J. M., Pernet-Fisher, J. F., Howarth, G. H., Magna, T., & Taylor, L. A. 2015. Helium isotopic evidence for modification of the cratonic lithosphere during the Permo-Triassic Siberian flood basalt event. Lithos, 216, 73-80.
    15. Howarth, G.H., Sobolev, N.V., Pernet-Fisher, J.F., Barry, P.H., Penumadu, D., Puplampu, S., Ketcham, R.A., Maisano, J.A., Taylor, D., & Taylor, L.A. 2014b. The secondary origin of diamonds: multi-modal radiation tomography of diamondiferous mantle eclogites. International Geology Reviews, 56(9), 1172-1180.
    16. Pernet-Fisher, J.F., Howarth, G.H., Liu, Y., Barry, P.H., Carmody, L., Valley, J.W., Bodnar, R.J., Spetsius, Z.V., & Taylor, L.A. 2014. Komsomolskaya diamondiferous eclogites: Evidence for oceanic crustal protoliths. Contributions to Mineralogy and Petrology, 167, 981-998.
    17. Howarth, G.H., Barry, P.H., Pernet-Fisher, J.F., Baziotis, I., Pokhilenko, N.P., Pokhilenko, L.N., Bodnar, R.J., Taylor, L.A., & Agashev, A.V. 2014a. Superplume metasomatism: Evidence from Siberian mantle xenoliths. Lithos, 184-187, 209-224.
    18. Howarth, G.H. & Skinner, E.M.W. 2013. Coherent Kimberlite at the Lace and Voorspoed (Group II) Kimberlite Pipes, Kroonstad Cluster, South Africa: Implications for root zone processes in the development of kimberlite pipes. Journal of Volcanology and Geothermal Research, 268, 1-16.