1. DSI-NRF CIMERA, Department of Geology, University of Johannesburg, PO Box 524, Auckland Park, 2006, South Africa e-mail: dirkvr@uj.ac.za
2. Department of Geology, University of the Free State, Bloemfontein, South Africa e-mail: clarkmd@ufs.ac.za
3. DSI-NRF CIMERA, Department of Geology, University of Johannesburg, PO Box 524, Auckland Park, 2006, South Africa e-mail: christofasmit@gmail.com
4. Faculty of Life and Environmental Sciences (Earth Evolution Sciences), University of Tsukuba, Tennoudai 1-1-1, Ibaraki 305-8572, Japan e-mail: tsunogae@geol.tsukuba.ac.jp
5. Korzhinskii Institute of Experimental Mineralogy, Russian Academy of Sciences, Academician Ossipian street 4, Chernogolovka, Moscow District, 142432, Russia, and Department of Petrology and Volcanology, Moscow State University, Vorob’evy Cory, Moscow, 142432, Russia e-mail: oleg@iem.ac.ru