geomorphic cycle  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 river drainage systems. It was assumed that, if the stage of
a landform was known, its history followed directly according to
a predetermined framework.  Thou