Earth Sciences 1022A/B Lecture Notes - Lecture 18: Deflation, Mafic, Bed Load
10 Jan 2017
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Document Summary
Deserts are dry places where there is low precipitation and little vegetation. Geologic processes 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 from 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. Bed load sand moves by saltation (grain collisions) and by rolling over the ground. Suspended load dust particles are pushed into the air by satiating sand grains, then swept up by the wind in dense clouds and carried high into the air. Wind erosion - occurs by deflation and abrasion.
