1. Department of Geomatics School of Geospatial Sciences and Technology, Ardhi University Dar Es Salaam Tanzania
2. Department of Geosciences UMR CNRS 8538, Ecole Normale Supérieure Paris France
3. Department of Earth and Atmospheric Sciences Purdue University West Lafayette Indiana USA
4. Now at Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology Cambridge Massachusetts USA
5. Royal Museum for Central Africa Tervuren Belgium
6. Umvoto Africa (Pty) Ltd Cape Town South Africa