Question

A penneplain is the- of the classical geomorphic cycle of erosion

Answer 1

Geomorphic cycle, also called geographic cycle, or cycle of erosion, theory of the evolution of landforms. In this theory, first set forth by William M. Davis between 1884 and 1934, landforms were assumed to change through time from “youth” to “maturity” to “old age,” each stage having specific characteristics. The initial, or youthful, stage of landform development began with uplift that produced fold or block mountains. Upon dissection by streams, the area would reach maturity and, ultimately, would be reduced to an old-age surface called a peneplain, with an elevation near sea level. The cycle could be interrupted by uplift during any period of the life cycle and thus returned to the youthful stage; this return is called rejuvenation. The geomorphic cycle could be applied to all landforms such as hillslopes, valleys, mountains, and riverdrainage systems. It was assumed that, if the stage of a landform was known, its history followed directly according to a predetermined framework.