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Rock veneer
A rock veneer is a geomorphic formation in which rock fragments (clasts) of gravel or cobble size form a thin cover over a surface or hillslope. Rock veneers are typically one or two clasts thick and may partially or fully cover the ground surface.〔Osterkamp, W.R., 2008, (''Annotated Definitions of Selected Geomorphic Terms and Related Terms of Hydrology, Sedimentology, Soil Science and Ecology'' ). U.S Department of the Interior U.S Geological Survey, Reston, Virginia, Open File Report 2008-1217, p. 49〕
Veneers typically form in semiarid and arid regions where chemical weathering rates and the potential for mass wasting are low. Other names for a rock veneer are rock-fragment cover (RFC), stone pavement, desert pavement, stony mantle, hammada and reg.
==Formation==
Rock veneers commonly arise from the weathering of resistant rocks of quartzite, felsic granites, coarse granites, and dense basalts. As these larger rocks are deposited on a surface, smaller sands either are removed by wind or water erosion, or settle and form a fine-grained layer beneath the larger veneer rocks. The larger clasts then rearrange and settle to form the rock veneer.〔Lenart, M.T., Osterkamp, W.R., and Toy, T.J., "Development of partial rock veneers by root throw in a subalpine setting". Wiley InterScience, Sept 27, 2005. 〕
Rock veneers form a variety of ways, with two major types; ''in situ'' veneers form in place by means of weathering, fluvial erosion, deflation (the removal of loose, fine-grained particles) or accretion; other veneers are transported via soil creep, sheet flooding or gully gravure (described below).〔Toy, Terrence, and Osterkamp, W.R., "The Stability of Rock-Veneered Hillslopes." International Journal of Sediment Research, Vol 14, No 3, 1999, pp. 63-73. 〕 Rock veneers are typically distinguished through six variables: particle size, particle density, stability characteristics, potential for storing mobile sediments, degree of abrasion, and varnishing.〔Jones, D.K.C., Cooke, R.U., and Warren, A., 1986. ("Geomorphological investigation, for engineering purposes of blowing sand and dust hazard" ). Quarterly Journal of Engineering Geology, Vol 19, pp. 251-270.〕
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