Associate Professor Stephen Prevec

Dept of Geology, Rhodes University

Makhanda (Grahamstown), South Africa, 6140
s.prevec@ru.ac.za
tel: +27 046 603-8313

 

Dr Prevec was initially educated in Canada, obtaining a B.Sc. and M.Sc. at McMaster University, and a Ph.D. at the University of Alberta, with a research emphasis on the application of radiogenic isotopic tracers and geochronometers to the emplacement history of Proterozoic mafic intrusions. He developed and broadened these interests to granitoids and to impact melts and associated phenomena through employment in isotope research labs at the Geological Survey of Canada (Ottawa), GEOTOP (Montreal), Laurentian University and the Ministry of Northern Development and Mines (Sudbury), and at the University of the Witwatersrand (Johannesburg), before accepting an appointment at Rhodes University in 2004. He is still learning.

His current research interests include the crystallisation, mechanical and thermal evolution of mafic igneous rocks (layered intrusions and sills) and their immediate surroundings, and of impact melts related to large impact structures, using petrography, mineralogy and major and trace element and isotope geochemistry as the primary tools. In his spare time he produces the newsletter of the Mineralogical Society of South Africa (Minsa), among other things.

Research keywords: layered intrusions, chromite, magnetite, radioisotope geochemistry, impact melt, PGE, igneous petrology.

Current projects:

  • Constraining the role of country rock assimilation on spinel stability in the Upper Critical Zone of the Bushveld Complex, South Africa
  • On the origins of graphite mineralisation in the Karoo: fluids, dolerites and the role of granitic fluids.
  • Constraints on the emplacement mechanisms for “saucer-shaped” end-Gondwanan dolerite sills, South Africa: evidence for multiphase emplacement
  • Petrogenesis of chromite-PGE reefs of the Critical Zone, Bushveld Complex, South Africa
  • Genetic relationships between granodiorites and migmatites in the Central Namaqua Belt
  • Constraining the role of crustal contamination in Cu sulphide ore mineralization in the Koperburg suite, Namaqualand, South Africa
  • Melting and shock effects on the geochronology of the Drury Township leucogabbro, Sudbury impact aureole, Canada

Selected publications:

PREVEC, S.A., LARGATZIS, S.A., BROWNSCOMBE, W. and SALGE, T. PGE distribution in Merensky wide-reef facies of the Bushveld Complex, South Africa: evidence for localized hydromagmatic control. Accepted pending revision for The Canadian Mineralogist (July 2021).

HUBER, M.S., KOVALEVA, E., CLARK, M.D., and PREVEC, S.A. (2021) Inhomogeneous distribution of lithic clasts within the Daskop granophyre dike, Vredefort impact structure: Implications for emplacement of impact melt in large impact structures. In Reimold, W.U., and Koeberl, C., (eds.), Large Meteorite Impacts and Planetary Evolution VI: Geological Society of America Special Paper 550, p. 1–267.

BÜTTNER, S.H., PREVEC, S.A., SCHMELDT, G.A. (2021) Petrogenesis of Mesoproterozoic granites of the Swartoup Hills region, Kakamas Domain, Namaqua Belt, South Africa.  Frontiers in Earth Science, 8, 1–23.

PREVEC, S.A. (2019) Igneous Rock Associations 23. The Bushveld Complex, South Africa: new insights and paradigms. Geoscience Canada, 45, 117-135.

PREVEC, S.A., BÜTTNER, S.H. (2018) Multi-phase emplacement of impact melt sheet into the footwall: offset dykes of the Sudbury Igneous Complex, Canada. Meteoritics and Planetary Science, DOI: 10.1111/maps.13076.

MAIER, W., PREVEC, S. A., SCOATES, J. S., WALL, C. J., BARNES, S. -J. and GOMWE, T. (2018) The Uitkomst intrusion and Nkomati Ni-Cu-Cr-PGE deposit, South Africa: trace element geochemistry, Nd isotopes and high-precision geochronology. Mineralium Deposita, 10.1007/s00126-017-0716-x.

HOWARTH, G.H., and PREVEC, S.A. (2013) Trace element, PGE, and Sr–Nd isotope geochemistry of the Panzhihua mafic layered intrusion, SW China: Constraints on ore-forming processes and evolution of parent magma at depth in a plumbing-system. Geochimica et Cosmochimica Acta, 120, 459-478.

HOWARTH, G.H., PREVEC, S.A. and ZHOU, M.-F. (2013) Timing of Ti-magnetite crystallisation and silicate disequilibrium in the Panzhihua Mafic Layered Intrusion: Implications for ore-forming processes. Lithos, 170–171, 73-89.

HOWARTH, G.H. and PREVEC, S.A. (2013) Hydration versus oxidation:  Modelling implications for Fe-Ti oxide crystallisation in mafic intrusions, with specific reference to the Panzhihua Intrusion, SW China. Geoscience Frontiers, 4, 555-569.

CHUTAS, N.I., BATES, E., PREVEC, S.A., COLEMAN, D.S. and BOUDREAU, A.E. (2011) Sr and Pb isotopic disequilibrium between co-existing plagioclase and orthopyroxene in the Bushveld Complex, South Africa: microdrilling and progressive leaching evidence for sub-liquidus contamination within a crystal mush. Contributions to Mineralogy & Petrology, 10.1007/s00410-011-0691-7.