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Geology & Earth Sciences vocabulary · Plate Tectonics & Structures

Fold

Meaning in geology & earth sciences, with examples

/foʊld/nounCommon term

In geology & earth sciences, fold means: A bend or curve in layers of rock, formed when the rocks are slowly squeezed by tectonic forces without breaking.

In Turkish: kıvrım

How it is used

The basic types are anticlines, which arch upwards with the oldest rocks in the core, and synclines, which sag downwards with the youngest rocks in the core. Geologists measure the fold axis and limbs. Also a verb: folded strata, the rocks were folded.

Example sentences

  1. The limestone layers in this cliff form a tight fold.

  2. Oil often collects at the top of an anticline, a type of upward fold.

Common collocations

  • anticline and syncline
  • fold axis
  • tight fold
  • fold belt
  • folded strata
  • faultA fracture in the Earth's crust along which the rocks on either side have moved. Sudden slip on a fault causes an earthquake.
  • stratumA single layer of sedimentary rock or sediment with similar features throughout, separated from the layers above and below it. The plural is strata.
  • strike and dipTwo measurements that describe the orientation of a rock layer or fault: strike is the compass direction of a horizontal line on it, and dip is its angle of tilt.
  • plate tectonicsThe theory that the Earth's outer shell is broken into large plates that move slowly, causing earthquakes, volcanoes, mountain building and the movement of continents.

More terms: Plate Tectonics & Structures

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