out·crop /ˈaʊtˌkrɑp/
  露出,露頭(vi.)露出
  Out·crop n. Geol. (a) The coming out of a stratum to the surface of the ground. --Lyell. (b) That part of inclined strata which appears at the surface; basset.
  Out·crop v. i. Geol. To come out to the surface of the ground; -- said of strata.
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  outcrop
       n : the part of a rock formation that appears above the surface
           of the surrounding land [syn: outcropping, rock
           outcrop]
       v : appear on the surface, come to the surface on the ground;
           "Big boulders outcropped"
       [also: outcropping, outcropped]