Weathering

A natural arch produced by erosion of differentially weathered rock in Jebel Kharaz (Jordan)

Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs in situ (on-site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity.

Weathering processes are either physical or chemical. The former involves the breakdown of rocks and soils through such mechanical effects as heat, water, ice and wind. The latter covers reactions to water, atmospheric gases and biologically produced chemicals with rocks and soils. Water is the principal agent behind both kinds,[1] though atmospheric oxygen and carbon dioxide and the activities of biological organisms are also important.[2] Biological chemical weathering is also called biological weathering.[3]

The materials left after the rock breaks down combine with organic material to create soil. Many of Earth's landforms and landscapes are the result of weathering, erosion and redeposition. Weathering is a crucial part of the rock cycle; sedimentary rock, the product of weathered rock, covers 66% of the Earth's continents and much of the ocean floor.[4]

  1. ^ Leeder, M. R. (2011). Sedimentology and sedimentary basins : from turbulence to tectonics (2nd ed.). Chichester, West Sussex, UK: Wiley-Blackwell. p. 4. ISBN 9781405177832.
  2. ^ Blatt, Harvey; Middleton, Gerard; Murray, Raymond (1980). Origin of sedimentary rocks (2d ed.). Englewood Cliffs, N.J.: Prentice-Hall. pp. 245–246. ISBN 0136427103.
  3. ^ Gore, Pamela J. W. "Weathering". Georgia Perimeter College. Archived from the original on 2013-05-10.
  4. ^ Blatt, Harvey; Tracy, Robert J. (1996). Petrology : igneous, sedimentary and metamorphic (2nd ed.). New York: W.H. Freeman. p. 217. ISBN 0716724383.