Professor Lewis Ashwal

Lew Ashwal serves as Distinguished Professor of Geology at the School of Geosciences, University of the Witwatersrand. He holds degrees from the State University of New York (B.Sc. 1971), University of Masachusetts (M.Sc. 1974) and Princeton University (Ph.D. 1979). Before joining academia, he was a post-doc at NASA Johnson Space Center (1979 – 1980) and a Staff Scientist at the Lunar and Planetary Institute (1980 – 1990), both in Houston Texas.  In 1990 he relocated to Johannesburg to take a Professor position at Rand Afrikaans University (now University of Johannesburg), and moved to Wits University in 2001 Prof. Ashwal is considered a world expert on anorthosites and related rocks, but has very broad interests in the geosciences, including tectonics and geodynamics, igneous petrology and geochemistry, origin and evolution of planetary crusts and mantles,  meteorites and their parent bodies, and the origin of magmatic ore deposits. He has been an NRF A-rated scientist since 2011.

Recent publications

Ashwal. L.D. (2020) Anorthosites. Encyclopedia of Geology, Second Edition, (eds. D. Alderton and S. Elias). Elsevier, in press.

Ashwal, L.D. (2019) Wandering continents of the Indian Ocean. Alexander L. Du Toit Memorial Lectures No. 35 (2018).  South African Journal of Geology, vol. 122, no 4, pp. 397-420, doi: 10.25131/sajg.122.0040

Ashwal, L.D. and Bybee, G.M. (2017) Crustal evolution and the temporality of anorthosites.  Earth Science Reviews, vol. 173, pp. 307-330. (INVITED REVIEW PAPER).  On-line version published 21 September, 2017, accessible at:

DOI: 10.1016/j.earscirev.2017.09.002

Hayes, B., Ashwal, L.D., Webb, S.J. and Bybee, G.M. (2017) Large-scale layering in the Main Zone of the Bushveld Complex and episodic downward magma infiltration. Contributions to Mineralogy and Petrology, vol. 172:13,  On-line version published 25 February, 2017, accessible at:       DOI: 10.1007/s00410-017-1334-4

Ashwal, L.D., Wiedenbeck, M. and Torsvik, T.H. (2017) Archaean zircons in Miocene oceanic hotspot rocks establish ancient continental crust beneath Mauritius.  Nature Communications, published 31 January, 2017, open access:, DOI: 10.1038/ncomms14086.

Ashwal, L.D., Torsvik, T.H., Horvath, P., Harris, C., Webb, S.J., Werner, S.C. and Corfu, F. (2016) A mantle-derived origin for Mauritian trachytes.  Journal of Petrology, vol. 57, no. 9, pp. 1645-1675.  doi: 10.1093/petrology/egw052

Ashwal, L.D., Patzelt, M., Schmitz, M.D. and Burke, K. (2016) Isotopic evidence for a lithospheric origin of alkaline rocks and carbonatites: an example from southern Africa.  Special Issue: Uniformitarianism and Plate Tectonics: A Tribute to Kevin C.A. Burke and John F. Dewey, Canadian Journal of Earth Sciences, vol. 53, pp. 1216-1226.   doi:10.1139/cjes-2015-0145

Roelofse, F., Ashwal, L.D. and Romer, R. (2015) Multiple, isotopically heterogeneous plagioclase populations in the Bushveld Complex suggest mush intrusion. Chemie der Erde / Geochemistry, v. 75, pp. 357-364.


Bybee, G.M. and Ashwal, L.D. (2015) Isotopic disequilibrium in Proterozoic anorthosites: insights into lower crustal contamination and the ascent of high-crystallinity magmas.  Geochimica et Cosmochimica Acta, vol. 167, pp. 286-300.

Owen-Smith, T.M. and Ashwal, L.D. (2015) Evidence for multiple pulses of crystal-bearing magma during emplacement of the Doros layered intrusion, Namibia.  Lithos, vol. 238, pp. 120-139.

Owen-Smith, T.M. and Ashwal, L.D. (2015) Geology of the early Cretaceous Doros layered mafic intrusion, Namibia: Complexity on a small scale.  South African Journal of Geology, vol. 118, no. 2, pp. 185-211.

Bybee, G.M., Ashwal, L.D., Gower, C.F. and Hamilton, M.A. (2015) Pegmatitic pods in the Mealy Mountains Intrusive Suite, Canada: Clues to the origin of the olivine-orthopyroxene dichotomy in Proterozoic anorthosites.  Journal of Petrology, vol. 56, no. 5, pp. 845-868.