Related Searches
Definitions

peneplain

peneplain

[pee-nuh-pleyn, pee-nuh-pleyn]

Gently undulating, almost featureless plain near sea level. This would form, theoretically, by various erosional processes that reduce areas of initially high relief produced by active uplift to areas of virtually no relief. The lack of present-day peneplains tends to discredit the theory, but some geomorphologists propose that large areas of low relief at high altitude in some mountains are evidence of uplifted peneplains. Others question whether the dynamic relationship between erosion and rock type would ever allow the development of a peneplain, even over very long timespans.

Learn more about peneplain with a free trial on Britannica.com.

A peneplain is the final stage in fluvial or stream erosion.

After the streams in an area have reached base level, lateral erosion is dominant - as the streams erode the highland areas between them. Finally, the upland is almost gone: the stream floodplains merge in an area of very low to no topographic relief. The resulting flat plain is the ultimate stage in the cycle of erosion or geographical cycle.

The streams within a peneplained region show extensive meandering and braiding. If the area is subsequently uplifted due to adjacent orogenic processes, without internal deformation within the peneplain, the streams will again begin downward erosion - creating incised meanders, water gaps, and other unique geomorphic features.

A peneplain can be mistaken for a depositional plain. However, the rocks beneath a peneplain have been folded and tilted by tectonic forces, while the rocks beneath a depositional plain lie in horizontal layers.

The peneplain concept was developed early in the 1900s by the geomorphologists, William Morris Davis and Walther Penck.

Search another word or see peneplainon Dictionary | Thesaurus |Spanish
Copyright © 2014 Dictionary.com, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature
FAVORITES
RECENT

;