William Moris Davis (1850-1934) was a prominent American geographer who founded the Association of American Geographers in 1904. He also put forward a theory of the cycle of erosion. The main points of his theory are as under:
- A cycle of erosion would affect all landscapes. The cycle consists of three stages. Youth Stage, Mature Stage, and the Old Stage.
- This cycle has three elements: Geologic Structure, Geographic Process, and Time (Stage).
- Every landscape is being acted upon by streams and other erosional processes. This is called the stage of degradation.
- A high mountain is worn down to a near plain surface called a Peneplain.
- In the initial stage, an upland is attacked by the stream and is converted into mountainous terrain.
- Then the mountains are lowered and take the shape of convex hilly interfluves (ridges between stream valleys).
- Finally, the hills are eroded away and a nearly flat plain (peneplain) is left. The remnants (hills left un-eroded) have been given the name of Monadnocks.
Criticism of Cycle of Erosion by Davis:
The theory of the cycle of erosion put forward by W.M. Davis has been criticized by many geographers because of the following reasons:
- W. Penck does not accept the three stages of the cycle of erosion viz., the youth stage, the mature, and the old stage.
- In the opinion of several German Geologists, the term ”Cycle” used by Davis is not correct because the process of erosion does not stop at any point from where it had commenced.
- In the view of Woolridge and Morgon, the cycle does not begin with the erosion of an uplifted mass. Actually, the cycle begins with the first emergence of a landmass on the surface of the ocean.
- According to O.Mall, Davis has ignored geological differentiation by simplifying his cycle of erosion.
- History does not support the theory of Davis that the uplift is sudden because actually, the process of the upliftment is slow and long covering millions of years.