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Weathering in geography UPSC


Table of Contents

  • Definition of Weathering
  • Types of Weathering
    • Chemical Weathering
      • Solution
      • Carbonation
      • Hydration
      • Oxidation
      • Reduction.
    • Physical or Mechanical weathering
      • Gravitational force
      • Thermal expansion and contraction
      • Freezing, thawing, and frost wedging
      • Salt weathering
    • Biological weathering
  • Significant of weathering




Weathering? 
Weathering is the breaking up and decay of exposed rocks, minerals, soil, wood, human-made structure by weathering elements such as temperature change, frost actions, plants, animal, and human activities. 
It is defined as the mechanical disintegration and chemical decomposition of rocks via weather and climate action



Types of Weathering:


Chemical weathering process:


Solution:
  • When content such as rock is dissolved in water or acid, this dissolved content is called a solution.
  • After contact with water, many solids disintegrate and mix up with Water.
  • Minerals like calcium carbonate and limestone are soluble in water.


Carbonations:
  • Carbonic acid is formed after the reaction of carbonate minerals and Co2 from air and soils.
  • Calcium carbonate and magnesium carbonate are dissolved in carbonic acids; resulting in cave formation.



Hydration:
  • Hydration is the chemical addition of water. 
  • When rock takes up water, it expands when temperature increase; as a results volume increase. This process gets reversed when the temperature cools. Continued replication of this process causes fatigue in rocks and leads to disintegration.


Oxidation:
  • The breaking of rocks occurred due to disturbances caused by the addition of oxygen. The minerals involved in the oxidation process are iron, magnesia, and sulfate.
  • Over time, the red color of oxides iron turns to yellow color. When oxide iron is put in below water where oxygen is absent, it turned into greenish and blushing color.



Physical or Mechanical weathering process
Physical or mechanical weathering is dependent on the following factors:

Gravitational force:

  • Gravitational force such as the overburden process leads to the disintegration of rocks.

Thermal expansion and contraction:
  • Rocks expand when temperature increase and rock shrink when temperature decrease. Shrinking and expansion of rocks lead to a fraction of rocks.
  • Water pressure is controlled by the wetting and drying cycle
  • Unloading and expansion lead to the removal of overlying rocks and cause the release of vertical pressure; as a result, upper layer rock expands and leads to the disintegration of rocks.

Freezing, thawing, and frost wedging:

  • Frost weathering, is due to the growth of ice within pores and cracks of rocks happened.
  • This type of weathering happened in high altitude and latitude regions.
Salt weathering:

  • Salt in rock expands due to thermal action and causes the splitting of individual grains


Biological weathering
  • Weakening and breaking of an object into the smaller object by plants, animals, and microbes.
  • The growth or movement of an organism leads to the removal of minerals and ions from the environment. Organisms like earthworms, termites, and rodents help in exposing new surfaces to chemical attacks and assist in the penetration of moisture and air.
  • Decaying plants and animals helps to produce humid, carbonic, and other acids that enhance chemical weathering.
  • Vegetables release acids that enhance the chemical weathering because of bacterial activities enhanced.
  • Algae extract the mineral from rocks.




Significant of weathering:
Weathering is responsible for soil formation.
Forest gets minerals from weathered materials.
Erosion only starts after weathering.
Weathering helps the extraction of valuable ore like iron, and magnesium which helps to increase the economy.

Try to solve the following questions:
  • Explain weathering and mass wasting and describe their geomorphic significance.  (UPSC 2014, 250 words, 20 marks)
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Unknown
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29 August 2022 at 15:31 ×

Very heplfull though

Congrats bro Unknown you got PERTAMAX...! hehehehe...
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