Skip to main content
Select Source:

fault

fault, in geology, fracture in the earth's crust in which the rock on one side of the fracture has measurable movement in relation to the rock on the other side. Faults on other planets and satellites of the solar system also have been recognized. Evidence of faults are found either at the surface (fault surface) or underground (fault plane). Faults are most evident in outcrops of sedimentary formations where they conspicuously offset previously continuous strata. Movement along a fault plane may be vertical, horizontal, or oblique in direction, or it may consist in the rotation of one or both of the fault blocks, with most movements associated with mountain building and plate tectonics. The two classes of faults include the dip-slip (up and down movement), which is further divided into normal and thrust (reverse) faults; and strike-slip (movement parallel to the fault plane). The San Andreas fault of California is of this type. In dip-slip faults the term "hanging wall" is used for the side that lies vertically above the other, called the "footwall." A fault in which the hanging wall moves down and the footwall is stationary is called a normal fault. Normal faults are formed by tensional, or pull-apart, forces. A fault in which the hanging wall is the upthrown side is called a thrust fault because the hanging wall appears to have been pushed up over the footwall. Such faults are formed by compressional forces that push rock together and are by far the most common of the dip-slip faults. All types of faults have been recognized on the ocean floor: normal faults occur in the rift valleys associated with mid ocean ridges spreading at slow rates; strike-slip faults appear between the offset portions of mid-ocean ridges; and thrust faults occur at subducting plate boundaries. Active faults, though they may not move for decades, can move many feet in a matter of seconds, producing an earthquake. The largest earthquakes occur along thrust faults. Some faults creep from a half inch to as much as 4 in. (1 to 10 cm) per year. Fault movements are measured using laser and other devices. Faults create interpretation problems for geologists by altering the relations of strata (see stratification), such as making the same rock layer offset in two vertical cross sections of a formation or making layers disappear altogether. Faults are often seen on the surface as topographical features, including offset streams, linear lakes, and fault scarps.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." The Columbia Encyclopedia, 6th ed.. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/fault

"fault." The Columbia Encyclopedia, 6th ed.. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/reference/encyclopedias-almanacs-transcripts-and-maps/fault

Fault

Fault

A fault is a crack or fracture in Earth's crust caused by the movement of landmasses, called plates, on either side of the fault line. Faults are found either at the surface (fault surface) or underground (fault plane). Most earthquakes occur along fault lines. The principle types of faults are: normal, reverse, thrust, and slip-strike.

Normal faults form when two plates are under tension and are being pulled or stretched apart. When this occurs, Earth's crust thins and one plate rises or drops against the other. More than 200 million years ago, North America and Africa were one huge landmass. Plates on either side of a massive fault line ruptured and began drifting apart. Oceanic waters, now known as the Atlantic Ocean, surged into the valley between, and two separate continents were born.

In contrast, reverse faults form from compression: two plates are being pushed into one another. The compression forces one plate up and over the other. (See photo on page 856.)

Thrust faults are low-angled reverse faults. Such faults are noteworthy because they produce great horizontal movement. Thrust faults have created most of the great mountain chains found around the world.

Strike-slip faults move horizontally along the fault line. The edge of one plate grinds against the edge of the other as it slips sideways. Most of these movements are quiet and continuous. Sometimes, however, plates shift with a sudden lurch, causing earthquakes. Such is the case with the San Andreas Fault in the western United States where the North American and Pacific plates meet. Land west of this fault is edging northwest.

[See also Earthquake; Geologic map; Plate tectonics ]

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Fault." UXL Encyclopedia of Science. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"Fault." UXL Encyclopedia of Science. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/fault-1

"Fault." UXL Encyclopedia of Science. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/fault-1

fault

fault / fôlt/ • n. 1. an unattractive or unsatisfactory feature, esp. in a piece of work or in a person's character: my worst fault is impatience. ∎  a break or other defect in an electrical circuit or piece of machinery: a fire caused by an electrical fault. ∎  a misguided or dangerous action or habit. ∎  (in tennis and similar games) a service of the ball not in accordance with the rules. 2. responsibility for an accident or misfortune: an ordinary man thrust into peril through no fault of his own. 3. Geol. an extended break in a body of rock, marked by the relative displacement and discontinuity of strata on either side of a particular surface. • v. [tr.] 1. criticize for inadequacy or mistakes: you cannot fault him for the professionalism of his approach. 2. (be faulted) Geol. (of a rock formation) be broken by a fault or faults. PHRASES: at fault 1. responsible for an undesirable situation or event; in the wrong: we recover compensation from the person at fault. 2. mistaken or defective: he suspected that his calculator was at fault. find fault make an adverse criticism or objection, sometimes unfairly or destructively: he finds fault with everything I do. — to a fault (of someone who displays a particular commendable quality) to an extent verging on excess: you're kind, caring and generous to a fault.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/fault-0

"fault." The Oxford Pocket Dictionary of Current English. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/fault-0

fault

fault Approximately plane surface of fracture in a rock body, caused by brittle failure, and along which observable relative displacement has occurred between adjacent blocks. Most faults may be broadly classified according to the direction of slip of adjacent blocks into dip-slip, strike-slip, and oblique-slip varieties. The term ‘dip-slip fault’ comprises both normal and reverse slip faults, and the special cases of low-angle lag and thrust faults. Strike-slip faults (wrench, transform, transcurrent) result from horizontal displacement (dextral or sinistral movements), and on a regional scale may involve transpression and transtension. See also VOIDS.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." A Dictionary of Earth Sciences. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." A Dictionary of Earth Sciences. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/fault

"fault." A Dictionary of Earth Sciences. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/fault

fault

fault In geology, a fracture in the Earth's crust along which movement occurs. The result of plate tectonics, faults are classified according to the type of movement. Vertical movements in the crust cause normal and reverse faults, while horizontal movements result in tear faults. Faults can occur in groups creating horsts, block mountains, grabens, or rift valleys.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." World Encyclopedia. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." World Encyclopedia. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/fault

"fault." World Encyclopedia. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/fault

Fault

FAULT

Neglect of care; an act to which blame or censure is attached. Fault implies anynegligence, error, or defect of judgment.

Fault has been held to embrace a refusal to perform an action that one is legally obligated to do, such as the failure to make a payment when due.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Fault." West's Encyclopedia of American Law. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"Fault." West's Encyclopedia of American Law. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/fault

"Fault." West's Encyclopedia of American Law. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/fault

fault

fault †lack, default XIII; defect in character, etc.; error; culpability XIV; (geol.) break XVIII. ME. faut(e) — (O)F. faut(e) :- Rom. *fallita, -tum, sb. use of fem. and n. of *fallitus, pp. of L. fallere FAIL2.
Hence faulty XIV.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." The Concise Oxford Dictionary of English Etymology. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/fault-1

"fault." The Concise Oxford Dictionary of English Etymology. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/fault-1

fault

fault See failure.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." A Dictionary of Computing. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." A Dictionary of Computing. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/fault

"fault." A Dictionary of Computing. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/fault

fault

fault •gestalt • asphalt •belt, Celt, dealt, dwelt, felt, gelt, knelt, melt, misdealt, pelt, Scheldt, smelt, spelt, svelte, veld, welt •fan belt • seat belt • lifebelt • sunbelt •rust belt • Copperbelt • heartfelt •underfelt • backveld • bushveld •Roosevelt •atilt, built, gilt, guilt, hilt, jilt, kilt, lilt, quilt, silt, spilt, stilt, tilt, upbuilt, wilt •Vanderbilt • volte •assault, Balt, exalt, fault, halt, malt, salt, smalt, vault •cobalt • stringhalt • basalt •somersault • polevault •bolt, colt, dolt, holt, jolt, moult (US molt), poult, smolt, volt •deadbolt • Humboldt • thunderbolt •megavolt • spoilt • Iseult •consult, cult, exult, indult, insult, penult, result, ult •adult • occult • tumult • catapult •difficult • Hasselt

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"fault." Oxford Dictionary of Rhymes. . Encyclopedia.com. 18 Aug. 2017 <http://www.encyclopedia.com>.

"fault." Oxford Dictionary of Rhymes. . Encyclopedia.com. (August 18, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/fault

"fault." Oxford Dictionary of Rhymes. . Retrieved August 18, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/fault