1. Department of Geology, University of Johannesburg, P.O. Box 524, Auckland Park, 2006 South Africa
2. Saskatchewan Isotope Laboratory, University of Saskatchewan, 114 Science Place, Saskatoon, Canada S7N 5E2.
3. Council for Geoscience, P.O. Box 572, Bellville, 7535 South Africa
4. Council for Geoscience, Private Bag x112, Pretoria, 0001 South Africa
5. National Institute of Polar Research, 10-3 Midori-cho, Tachikawa, Tokyo 190-8518, Japan
6. Direcção Nacional de Geologia, Maputo, Mozambique