An escarpment is a geologic formation caused by faulting or erosion where a cliff or very steep slope is formed over time. Escarpments can be found on every continent and they are also present on a number of planets and moons, as astronomers have learned with the assistance of close flybys and robotic exploration. Their size and composition can be quite variable, and sometimes the escarpment marks a border between different climate zones and other features of interest, making it an important landmark.
In the case of an escarpment caused by faulting, a series of earthquakes over time pushes one section of ground up or allows another to fall away. Different geological layers can be seen in the face of the escarpment, illustrating different periods in the area's geologic history. Often, the lowland area becomes covered in deposits of rich, silty soils and may support a variety of plants and animals, while the exposed highland may become more barren and rocky as a result of erosion.
Erosion of escarpments is a gradual process, and it is usually seen near geologic boundaries, where rocks of different types start to wear unevenly. Soft sandstone may be eaten away, for example, leaving harder granite behind. The wear of the weaker stone can be the result of scouring winds, water, ice, and other weather events. Often, the soft features of the raised section of earth are worn away and can leave behind bizarre and visually interesting formations.
Escarpments can present significant barriers to travel, as they may be very high, and it will be necessary to either bridge lowlands, create a road up the face of the rock, or travel around to more level ground. They can also provide shelter from wind and rain, making the area at the foot of an escarpment a popular area for human settlements. The tendency to accumulate topsoil in the lowlands can be useful for agriculture as well.
For people like geologists and paleontologists, an escarpment can represent a prime opportunity. People can see geologic history neatly mapped out in the layers of the rock face and may take samples to learn more about the geologic history of the area. Fossils can be identified to see what kind of organisms lived there and to collect information about the climate during previous geologic eras. This information can be applied to the understanding of other rock formations in the area as well.
