612 SEDIMENTARY PROCESSES/Aeolian Processes Aeolian Processes N Lancaster, Desert Research Institute, Reno, NV, and United States Geological Survey, Reston, VA, USA ß 2005, Elsevier Ltd All Rights Reserved Introduction Aeolian processes, involving erosion, transportation, and deposition of sediment by the wind, occur in a variety of environments, including beaches, semi-arid and arid regions (e.g., cold and hot deserts), agricultural fields, and some terrestrial planets, notably Mars and possibly Venus Common features of these environments are a sparse or non-existent vegetation cover, a supply of fine sediment (clay, silt, and sand size), and strong winds Aeolian processes are responsible for the emission and/or mobilization of dust and formation of areas of sand dunes They largely depend on other geological agents (e.g., rivers, waves) to supply sediment for transport Despite assertions by many early workers, erosion of bedrock by the wind is not a significant process in most regions settling velocity, and hence particle size, and wind shear stress and turbulence intensity Very small particles (