1. Department of Geosciences, The Pennsylvania State University, State College, PA, USA
2. Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, NY, USA
3. Department of Earth and Environmental Sciences, Tulane University, New Orleans, LA, USA
4. Geological Survey of Malawi, Zomba, Malawi
5. Geological Survey of Tanzania, Dodoma, Tanzania
6. University of Dar-es-Salaam, Dar-es-Salaam, Tanzania
7. Department of Physics & Astronomy, University of Rochester, Rochester, NY, USA