What does outcrop mean?
An outcrop is a mass of rock that stands exposed at the surface, projecting from the surrounding soil, vegetation, or land. The word is especially useful in geology, where it describes bedrock that has become visible through erosion or other natural processes; an outcrop may be a low ledge, an isolated block, or a larger rocky ridge. It can also be used as a verb: a formation “outcrops” when part of it appears at the surface. The related expression “crop out” is common in geological description. Although an outcrop is often associated with steep or rugged terrain, it need not form a cliff; it is simply a visible exposure of rock. The word therefore conveys both a physical landform and the broader geological idea of a hidden layer reaching the landscape's surface.
A visible mass of rock projecting from the surrounding ground or land surface.
"The climbers scrambled up the steep outcrop overlooking the valley."
Common in geology and physical geography for an exposure of bedrock at the surface.
To appear at the surface as a rock formation or exposed mass.
"The fault line outcrops near the northern end of the ridge."
Often used intransitively in geological description; “crop out” is a common phrasal variant.
The regular plural is used for separate exposed rock masses.
"Several outcrops of limestone are visible from the coast."
An outcrop is geology's way of showing where a hidden layer of the Earth has reached the surface.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does outcrop come from?
The word is a compound of “out” and “crop,” with “crop” used in the sense of projecting or protruding. The term developed in English during the 19th century, particularly in geological writing, to refer to a visible exposure of rock. Related forms include “crop-out” and “upcrop,” which also concern the appearance or movement of material toward the surface.
Related word forms
How outcrop is actually used
In geology, the term is especially common in British and American English. As a verb, it is often used with “out” as in “crop out,” meaning to emerge at the surface.