1. a Department of Earth Resources Surveys, Geology Division , International Institute for Aerospace Surveys and Earth Sciences (ITC) , 350 Boulevard 1945, Enschede, AA, 7500, The Netherlands
2. b Department of Earth Resources Surveys, Mineral Exploration Division , International Institute for Aerospace Surveys and Earth Sciences (ITC) , Kanaalweg 3, EB, Delft, 2628, The Netherlands