Rock veneer
A rock veneer is a
Formation
Rock veneers commonly arise from the weathering of resistant rocks of
Rock veneers form a variety of ways, with two major types; in situ veneers form in place by means of
Gully Gravure
Gully gravure is a transportation process by which rock veneers can be formed. Valleys formed of
Root Throw
Root throw is the process that occurs when a tree topples, raising its rootwad and the rock fragments in it. Fine sediment falls back into the rootwad pit or travels downstream, but coarse sediments form a local rock veneer around the rootwad. This local rock veneer is larger than the pit of the rootwad, as falling clasts extend the area of veneer. In a study[
Root throw produces a rock veneer when there are a large number of clasts near the surface, where there are: a slow rate of chemical weathering, insufficient precipitation to move the large clasts, high velocity winds, conditions favorable to shallow-rooted trees, and trees large enough to embed coarse rock in their roots.
Effects
Hillslopes with a rock veneer are more stable than those without and have lower erosion rates. Rock veneers form a rocky armor on the hillslope which prevents the erosion of smaller sediments and stabilizes the slope. Rock veneers, forming when influx and outflux sediment rates are equal, indicate a hillslope in equilibrium, partly due to their protective cover on the slope. Erosion rates on veneered hillslopes are low to moderate.
Notes
- ^ 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
- doi:10.1002/esp.1222
- doi:10.1002/esp.1222
- ^ 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.