define peneplain in geography
Answers
Explanation:
The existence of some peneplains, and peneplanation as a process in nature, is not without controversy, due to a lack of contemporary examples and uncertainty in identifying relic examples.[1][4] By some definitions, peneplains grade down to a base level represented by sea level, yet in other definitions such a condition is ignored.[4] Geomorphologist Karna Lidmar-Bergström and co-workers consider the base level criterion crucial and above the precise mechanism of formation of peneplains, including this way some pediplains among peneplains.[5][6]
While peneplains are usually assumed to form near sea level it has also been posited that peneplains can form at height if extensive sedimentation raises the local base level sufficiently[7] or if river networks are continuously obstructed by tectonic deformation.[8] The peneplains of the Pyrenees and Tibetan Plateau may exemplify these two cases respectively.[7][8]