Outcrops

An outcrop, in geology, is an exposure of bedrock or an ancient surface at the Earth's surface. Outcrops occur when bedrock or surficial deposits are not hidden by soil, vegetation, or sediment and can be seen or walked upon.

Outcrops form when overlying material is removed by weathering and erosion, or when tectonic forces uplift bedrock. They can appear as cliff faces, river cuts, road cuts, quarries, or mountaintop exposures. The exposed rock may be sedimentary, igneous, or metamorphic.

Outcrops provide direct access to rock types, textures, structures, and fossils. They are crucial for mapping geological formations, interpreting depositional environments, and constraining the timing of geological events. They also influence soil development, landscape patterns, groundwater flow, and resource exploration.

Study methods include field observation, stratigraphic logging, mapping of structural features, and laboratory analysis of rock samples. In sedimentary outcrops, fossils help date strata and reconstruct past environments. Preservation of outcrops depends on climate, rock strength, and human activity, and their study remains a core part of field geology.