Stephy D. Makungwa
School of GeoSciences The University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP, UK
Bunda College of Agriculture, Lilongwe University of Agriculture and Natural Resources, Lilongwe, Malawi
Iain H. Woodhouse
School of GeoSciences The University of Edinburgh, Drummond Street, Edinburgh, EH8 9XP, UK