1. School of Geosciences, University of the Witwatersrand, Johannesburg, 2050, South Africa Shango Solutions, HHK House, 22 Ethel Street, Johannesburg 2194, South Africa
2. Department of Geosciences, University of Cape Town, South Africa
3. Geo-Consult International (Pty) Ltd. Present address: PO Box 469, Struben’s Valley, 1735, South Africa
4. CIMERA, Department of Geology, University of Johannesburg, Auckland Park 2006, South Africa
5. Research School of Earth Sciences, Australian National University, Canberra, ACT0200, Australia
6. School of Geosciences, University of the Witwatersrand, Johannesburg, 2050, South Africa