1. n. [Geology]

A variety of sealed geologic container capable of retaining hydrocarbons, formed by changes in rock type or pinch-outs, unconformities, or sedimentary features such as reefs. Structural traps, in contrast, consist of geologic structures in deformed strata such as faults and folds whose geometries permit retention of hydrocarbons.

See related terms: fault trap,  hydrocarbon,  pinch-out,  reef,  sedimentary,  structural trap,  subsalt,  trap,  unconformity