Outcrop
Outcrop
An outcrop consists of bedrock exposed at Earth–s surface. Geologists often seek out outcrops to learn about the geology of an area, and geology students visit outcrops as illustrations of the principles of geology.
Mountainous regions, where any loosened Earth material is quickly removed by erosion or mass wasting, contain some of the best outcrops because a greater proportion of bedrock is exposed. Rocks crop out especially well across steep slopes, above the tree line (elevation above which trees cannot grow), and on land scraped free of soil by glaciers. Sediment collects and plants grow in flatter areas, obscuring rocks and making outcrops rare in lowlands except where they have been incised by streams. In some areas soil and sediment may completely cover all the underlying rock, such as in the southeastern United States. However, in the desert southwest, the opposite is often the case.