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Erosion surfaces geography UPSC | Geomorphology | Physical Geography

Erosion surfaces geography UPSC | Geomorphology | Physical Geography

16:05

Table of Contents

  • What is erosion surface?
  • How to find out the erosional surface
  • Examples of Erosion surfaces:
    • Peneplains
    • Endrumpf
    • Panplain
    • Pediplain
    • Base level
  • Erosional Surface Vs erosional Landforms
What is erosion surface?

 The surface is created by the process of erosion and formed in the last stage of the erosional cycle, and is not formed by deposition and tectonic fault.
The following point will clarify the erosional surface in India:
  • The erosional surface can not have in the Himalayan region, because they are in the youthful stage and still uplifting and going through the glacial cycle.
  • The erosional surface can not be found in the Great Indian plains, because it has been made up by deposition.
  • Western coastal plains are not an erosion surface because it has been made up of tectonic fault.
  • The possibility of the erosional surfaces is in the Aravali range, Chota Nagpur Plateau, and Deccan Plateau region because:
    • They are very old.
    • No tectonic upliftment or faulting is happening as of now.
    • No large-scale construction activities such as sedimentary deposition are happening.

 How to find out the erosional surface?
The erosional surface can find out by making a superimposed profile of geographical landforms in given areas.
The erosional surface may be found on the point where two or more geographical profiles cuts.
The below diagram is a linear profile of the different heights of geographical areas:
Erosion surface
Erosion surface
When we combine these linear profiles that combined profile will be called a superimposed profile, and cutting points at different heights will be the erosional surface of given geographical areas.

The following are examples of erosion surface that are made up of different processes:
  • Peneplains
  • Endrumpf
  • Panplain
  • Pediplain
  • Base level
Peneplains
It is almost featureless plains after the final stage of the erosion cycle as explained by Davis.
Peneplains is not a flat plain but a very faint relief where the river flows in wide valleys with a very gentler slope. This erosional surface is found in a humid climate and is made up of fluvial erosion.
50 % of the river channel is the first upper part made up of erosion and the other half or lower part of the river channel is made up of depositional.  Peneplain erosional surface is found in the first upper part of the river channel.
Endrumpf:

It is also found in the Humid region and propounded by W. Penck in the erosional cycle.
Panplains
It is also found in humid and semi-humid climates. Panplain is much flatter than peneplains due to lateral erosion in the erosion cycle. The concept of Panplain is given by C H Crickmay(1933).
A Plain is formed by joining more than one flood plain.
Pediplains
The concept of Pediplain is given by LC king in 1948. It is found in arid, semi-arid, and savanna areas and is characterized by rocky boulders, and isolated hills. It is formed by the merger of many pediments.
Base level:
After reaching the base level river stream can not erode further.
If the base level is sea level then it is called the ultimate base level.




Difference between Erosion surface and erosional Landforms:

Erosion surface is formed by the last stage of the erosional cycle in the old stage fluvial or other landforms whereas erosional landforms can be formed in any stage of the erosional cycle.
The following are the erosional landforms:
  • Erosional landform by running water:
    • River Valleys
    • Potholes and Plunged pool
    • River Terrace
    • Waterfall
    • Meanders
    • Oxbow lake
    • Braided Channel
  • Erosional landform by Groundwater
    • Sinkhole
    • Caves
    • Karst Valley
  • Erosional landforms by Sea wave
    • Bay
    • Lagoon
    • Sea cave
    • Sea Arches
    • Stacks
    • Sea Cliff
  • Erosional landforms by Glaciers
    • Cirques
    • Horns
    • U shaped Valleys
    • Hanging Glacial Valley
  • The erosional landform in the desert
    • Pediment
    • Inselbergs
    • Zeugen
    • Pediplains
    • Balson
    • Deflection basin or blowout
    • Playas
    • Mushroom rock
Try to solve the following questions:
  • State the concept of erosion surfaces and highlight the factors responsible for their development.  (UPSC 2014, 200 words, 15 marks)

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