Fault (geology)

"Fault line" redirects here. For other uses, see Fault line (disambiguation).
"Shatter belt" redirects here. For the concept in geopolitics, see Shatter belt (geopolitics).

Satellite image of a fault in the Taklamakan Desert. The two colorful ridges (at bottom left and top right) used to form a single continuous line, but have been split apart by movement along the fault.

In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic forces, with the largest forming the boundaries between the plates, such as the megathrust faults of subduction zones or transform faults.[1] Energy release associated with rapid movement on active faults is the cause of most earthquakes. Faults may also displace slowly, by aseismic creep.[2]

A fault plane is the plane that represents the fracture surface of a fault. A fault trace or fault line is a place where the fault can be seen or mapped on the surface. A fault trace is also the line commonly plotted on geologic maps to represent a fault.[3][4]

A fault zone is a cluster of parallel faults.[5][6] However, the term is also used for the zone of crushed rock along a single fault.[7] Prolonged motion along closely spaced faults can blur the distinction, as the rock between the faults is converted to fault-bound lenses of rock and then progressively crushed.[8]

  1. ^ Lutgens, Frederick K.; Tarbuck, E.J.; Tasa, D. (illustrator) (2012). Essentials of geology (11th ed.). Boston: Prentice Hall. p. 32. ISBN 978-0321714725.
  2. ^ Ohnaka, M. (2013). The Physics of Rock Failure and Earthquakes. Cambridge University Press. ISBN 978-1-107-35533-0.
  3. ^ "fault trace", Earthquake Glossary, United States Geological Survey, retrieved 10 April 2015
  4. ^ Tristram, Robert (30 April 2003), Where are the Fault Lines in the United States East of the Rocky Mountains?, United States Geological Survey, archived from the original on 18 November 2009, retrieved 6 March 2010
  5. ^ “Fault zone.” Merriam-Webster.com Dictionary, Merriam-Webster. Retrieved 8 Oct. 2020.
  6. ^ Fillmore, Robert (2010). Geological evolution of the Colorado Plateau of eastern Utah and western Colorado, including the San Juan River, Natural Bridges, Canyonlands, Arches, and the Book Cliffs. Salt Lake City: University of Utah Press. p. 337. ISBN 9781607810049.
  7. ^ Caine, Jonathan Saul; Evans, James P.; Forster, Craig B. (1 November 1996). "Fault zone architecture and permeability structure". Geology. 24 (11): 1025–1028. Bibcode:1996Geo....24.1025S. doi:10.1130/0091-7613(1996)024<1025:FZAAPS>2.3.CO;2.
  8. ^ Childs, Conrad; Manzocchi, Tom; Walsh, John J.; Bonson, Christopher G.; Nicol, Andrew; Schöpfer, Martin P.J. (February 2009). "A geometric model of fault zone and fault rock thickness variations". Journal of Structural Geology. 31 (2): 117–127. Bibcode:2009JSG....31..117C. doi:10.1016/j.jsg.2008.08.009.