Earth Sciences 1022A/B Lecture Notes - Lecture 18: Suspended Load, Deflation, Silt
11 Apr 2016
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Chapter 18 - deserts and winds: deserts are dry places where there is low precipitation and little vegetation. In spite of lack of water and vegetation, processes still occur: weathering. Almost entirely mechanical and very slow due to low precipitation; however, clays and thin soils form by oxidation of ferromagnesian silicate minerals: water. Ephemeral streams and flash floods from short, intense rainstorms do most of the erosion of desert surfaces, especially sediment not anchored by vegetation. Wind can move faster than water and carries sediment farther and higher than streams because flow is not confined to channels: bedload. Sand moves by saltation (grain collisions) and by rolling over the ground. Dust particles are pushed into the air by saltating sand grains, then swept up by the wind in dense clouds and carried high into the air. Occurs by deflation and abrasion: deflation.
