Identifying Sources of Aeolian Mineral Dust: Present and Past - Mineral Dust: A Key Player in the Earth System - page 60

Fig. 3.4 Soil geography of western Africa, redrawn and generalized from U.S. Department of
Agriculture, Natural Resources Conservation Service “Global Soil Regions” map ( http://www.
soils.usda.gov/use/worldsoils/mapindex/order.html ) and clay minerals typically found in each soil
type. Also shown are calculated back trajectories of dust samples with contrasting clay mineral
compositions collected off the coast of Africa in 1998 (Redrawn from Stuut et al. 2005 )