peneplain

thumb|300px|Aerial view of the almost flat and drowned peneplain at Belcher Islands, Hudson Bay, Canada, cutting across numerous [[geologic folds.]]

In geomorphology and geology, a peneplain is a low-relief plain formed by protracted erosion. This is the definition in the broadest of terms, albeit with frequency the usage of peneplain is meant to imply the representation of a near-final (or penultimate) stage of fluvial erosion during times of extended tectonic stability. Peneplains are sometimes associated with the cycle of erosion theory of William Morris Davis, but Davis and other researchers have also used the term in a purely descriptive manner without any theory or particular genesis attached.