Denudation chronology | Geomorphology | Principle Of Geography

 

Geomorphology

Principle Of Geography

Geography Complete Study Material

(Paper - I)

Denudation Chronology

Denudation chronology simply means reconstruction of denudational history of a given region. This is primarily based on ‘historical or chronological approach of landform study which involves the basic concepts ‘that there is sequential change in landform s through time’, ‘principles of uniformitarianism ,’ ‘cyclic nature o f earth’s history ’, ‘palimpsest topography ’ and Davisian model of ‘cyclic evolution of landforms’. The primary goal of this approach is to reconstruct the chronological history of denudation of a given region know n as denudation choronological and ‘to identify , date and interpret planation surfaces developed in past cycles and subcycles of erosion’ (R .J. S m all, 1970).

Denudation: denudation involves the processes that cause the wearing away of Earth’s surface by moving water, ice, wind, and waves. This leads to a reduction in elevation and in relief of landforms and of landscapes.

• Denudation = (Weathering + Erosion)

This is primarily based on historical or chronological approach of landform study which involves the basic concepts such as:

• ‘There is sequential change in landforms through time’,
• ‘Principles of uniformitarianism‘
• ‘Cyclic nature of earth ’s history ’
• ‘Palimpsest topography ‘and
• Davisian model of ‘cyclic evolution of landforms’.

The denudation chronology approach suffers from certain perceptible weaknesses such as:

• An important criticism which has been levelled against the denudation chronology approach is that it succeeds in explaining directly only very small parts of the existing landscape, namely the fragments of former (erosion) surfaces which have been dissected and almost totally destroyed in some cases by more recent erosion‘.
• Secondly, Historical approach is highly deductive and speculative because the old erosion surfaces and remnant forms have been so greatly modified by subsequent processes that it becomes difficult or say impossible to find out their original forms and initial heights.

• The dating of erosion surfaces is also highly speculative as valid geological evidences are not available.