Geology

Geology

Professor
Geochemistry and Petrology

Head of Department

Ph.D.   University of Alberta (Canada)
M.Sc.   McMaster University (Canada)
B.Sc. (Hons) Geology   McMaster University (Canada)
PGDipHE   Rhodes University

Phone: +27 (0)46 603-8313 or -8309

E-mail:  s.prevec(at)ru.ac.za

GOOGLE SCHOLAR

RESEARCH INTERESTS

My interests involve the study of mafic intrusions and associated high grade metamorphic rocks, based on field and thin section petrography, major, trace and radioisotope geochemistry, and geochronology. Often associated with these rocks is Cu-Ni±PGE sulphide and oxide mineralisation in various settings, whose origins and distribution are closely tied to the magmatic petrogenesis and/or subsequent metamorphism. A more detailed description of my research interests can be found under Projects 2023.

• Rift-associated mafic intrusions (mostly Precambrian) and associated rocks
• Large meteorite impact melt evolution

TEACHING

• EAR101: Introductory Earth Sciences
• GLG102: Petrology
• GLG2 and 3: Igneous petrology
• Honours: Magmatic ore-forming processes
• Honours field course: Impacts, intrusions and greenstone belts

POST-DOCTORAL EMPLOYMENT

• Senior Research Officer, BPI Geophysics / Hugh Allsopp Laboratory, University of the Witwatersrand, Johannesburg, South Africa (1998-2004)
• Laurentian University, Sudbury, Canada (funded in part through a research/exploration contract with Inco Ltd.) (1994-1998)
• GEOTOP, University of Quebec at Montreal, Canada (funded by analytical contracts with Cominco) (1992-1994)
• Geochronology Section, Geological Survey of Canada, Ottawa, Canada (1991-1992)

SELECTED PAPERS

>30 published papers in refereed journals, internally-reviewed outputs, and book chapters. Selected recent offerings listed here.

• BARNES, S.-J., MANSUR, E.T., MAIER, W.D. & PREVEC, S.A. (2022) A comparison of trace element concentrations in chromite from komatiites, picrites and layered intrusions: Implications for the formation of massive chromite layers. Canadian Journal of Earth Science 60, 97–132. dx.doi.org/10.1139/cjes-2022-0064.

• PREVEC, S.A., LARGAZIS, S.A., BROWNSCOMBE, W., SALGE, T. (2021) PGE distribution in Merensky wide-reef facies of the Bushveld Complex, South Africa: Evidence for localized hydromagmatic control. The Canadian Mineralogist, 59(6), 1305–1338. 

• 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.

• GANINO, C., HARRIS, C., ARNDT, N., PREVEC, S.A. and HOWARTH, G.H. (2013) Assimilation of carbonate country rock by the parent magma of the Panzhihua Fe-Ti-V deposit (SW China): evidence from stable isotopes. Geoscience Frontiers, 4, 547-554.

• ZHOU, M.F., CHEN, W.T., WANG, C.Y., PREVEC, S.A., LIU, P.P. and HOWARTH, G.H. (2013) Two stages of immiscible liquid separation in the formation of Panzhihua-type Fe-Ti-V oxide deposits, SW China. Geoscience Frontiers 4, 481-502.

   

  Abstracts

  Fifty-five odd abstracts published in international and national conference proceedings, accompanying oral presentations, and occasionally posters.  Details for some recent ones are provided here: 

• DYAN, S. and PREVEC, S.A. (2023) Assimilation of siliceous and carbonaceous xenoliths in the Upper Critical Zone of the northern limb, Bushveld Complex: Implication for hybridization reactions. GSSA GEOCONGRESS, Stellenbosch, Jan. 2023.

• JOHNSTONE, S.D., VAN NIEKERK, D. and PREVEC, S.A. (2023) Petrography, geochemistry, and remote sensing of an anomalous Karoo diorite. GSSA GEOCONGRESS, Stellenbosch, Jan. 2023.

• PREVEC, S.A., LARGATZIS, S.A., SALGE, T. and BROWNSCOMBE, W. (2023) Evidence of localized hydromagmatic control on PGE distribution in the Merensky Reef, Bushveld Complex, South Africa. GSSA GEOCONGRESS, Stellenbosch, Jan. 2023. Keynote presentation.

• PREVEC, S.A., LETETE, K., MOLYNEUX, D., NCHEE, M. and NTANTISO, M. (2023) Evidence for temporal shifts in basaltic magma compositions in the Karoo dolerites, and the implications for the role of cumulus processes. GSSA GEOCONGRESS, Stellenbosch, Jan. 2023. Keynote presentation.

• PREVEC, S.A. (2022) On the importance of Geoheritage. GSSA GEOHERITAGE CONFERENCE. Johannesburg, May 2022. Invited keynote presentation.DYAN, S., PREVEC, S.A. and TONNELIER, N. (2020) Modelling the role of carbonate assimilation on the stability of spinels: a focus on the Northern Limb chromites, Bushveld Complex, South Africa. Geological Society of America Annual Meeting. Nov. 2020.

• BARNES, S.-J., MANSUR, E., PAGÉ, P., MERIC, M., ARGUIN, J.P. and PREVEC, S. (2020) Major and trace element compositions of chromites from the Stillwater, Bushveld and Great Dyke intrusions compared with chromites from komatiites, boninites and Large Igneous Provinces. 14th International Ni-Cu-PGE Symposium, virtual conference (August 2020).

• PREVEC, S.A. and BÜTTNER, S.H. (2019) Emplacement of melt sheet injection into impact crater footwall: implications from offset dykes of the Sudbury Igneous Complex, Canada. Proceedings of Large Meteorite Impacts VI (Brasilia, Brazil, Sept. 2019).

• PREVEC, S.A., DE BRUYN, J.A. and NXESI, B. (2019) Shocked and juvenile zircons in impact crater footwall, Sudbury, Canada: partial melting of a reactivated footwall mylonite zone. Proceedings of Large Meteorite Impacts VI (Brasilia, Brazil, Sept. 2019).

• NTSALUBA, B. & PREVEC, S.A. (2017) Petrogenesis of the Mount Ayliff Complex: evidence from Cr–spinel geochemistry. Igneous and Metamorphic Studies Group 9th Annual Conference (IMSG), South Africa.

• ARUNACHELLAN, Y. & PREVEC, S.A. (2017) Constraints on mineralisation in the MG 1 and 3 chromitites, Bushveld Complex, South Africa.. Igneous and Metamorphic Studies Group 9th Annual Conference (IMSG), South Africa.

• NTANTISO, M. & PREVEC, S.A. (2017) Constraints on the emplacement of the Colesberg Sill, Karoo Supergroup. Igneous and Metamorphic Studies Group 9th Annual Conference (IMSG), South Africa.

• PREVEC, S.A., LARGATZIS, S.A. and RAINES, M.E. (2016) Constraints on the origins of PGE-mineralized chromitite reefs from PGE distributions and isotopic compositions of the Merensky Reef, Bushveld Complex, South Africa. Geological Society of America Penrose Conference, Red Lodge, Montana, U.S.A., August 2016. (invited keynote presentation).

• PREVEC, S.A. and BÜTTNER, S.H. (2016) Multi-phase emplacement of impact melt sheet into the footwall: offset dykes of the Sudbury Igneous Complex, Canada. Igneous and Metamorphic Studies Group 8th Annual Conference (IMSG), Langebaans, South Africa.

• PREVEC, S.A. (2015) Chromite and PGE coprecipitation by crustal contamination or magma mixing revisited: genetic and exploration implications. PACRIM 2015 Hong Kong, China (March, 2015).(invited keynote presentation).

CURRENT POSTGRADUATE STUDENTS

1. Ms Emmanuella Ikwen (2021- 2024) MSc student, Rhodes University, “Origin and metallogenic significance of alkali metasomatism in the Paleoproterozoic Mapedi Formation, Kalahari Manganese Field, South Africa”. Funded by PRIMOR. Currently in review by external examiners. Expecting to graduate in April 2023.
2. Ms Siyasanga Dyan (2021- ) PhD student, Rhodes University, “Constraining the role of contamination on spinel stability in the Upper Critical Zone of the Bushveld Complex, South Africa”, funded by CIMERA grant to SP, NRD bursary to candidate, and supported by Ivanplats (Pty) Ltd., South Africa/Canada.
3. Mr Shawn Johnstone (2021- 2025) MSc student, Rhodes University, “Characterisation of a mineralised igneous intrusion in the Chris Hani district (Cradock, Eastern Cape, South Africa)”, (cosupervisor, with Dr van Niekerk).
4. Mr Royston Lobow (2020- 2024) MSc student, Rhodes University, “Developing a model for financing ore and resource development sale by hedging future sales (futures market principles)”. (Supervisor, with Prof. Keeton, Dept of Economics). Submission planned for mid-2023.
5. Ms Nosibulelo Zilibokwe (2023- ) Ph.D. student, “Trace element concentration and distribution in Cu-Sulphides: Implication for the genesis of Cu mineralization in carbonatites at the Phalaborwa Igneous Complex, South Africa”. (Supervisor, with Dr N. Hammond, U. Limpopo, as cosupervisor). Part-time student, employed by Council for Geoscience.