Weathering

(GS PAPER-1 Geomorphology

Source-gsi.in)

Context-

Weathering is an in-situ process of disintegration and decomposition of rocks, where the movement of debris is not involved (though some downslope movement under gravitational force is possible). Weathering is an important phenomenon of degradation of mountains and plateaus, which results in the development of soil.

Various types of weathering include: 

1. Physical weathering- It is the disintegration of rocks due to physical forces by various geomorphic agents. 

      • Effects of changing temperature, impact by water, wind or glacier, freeze and thaw mechanism in colder regions are more pronounced effects – leading to physical weathering.
      • Such weathering is more common in hot and dry areas

2. Chemical Weathering- Here the disintegration of rocks occurs due to the exchange of ions and chemical alteration in the composition of rocks through various chemical reactions.

    • They are more pronounced in wet regions as water forms acid and rocks disintegrate through the processes like a solution, carbonation, hydrolysis, hydration, etc.
    • Other ion exchange methods are oxidation, leachates, etc.

3. Biological weathering is done by biological agents like flora, fauna, and above all humans. This involves processes like burrowing, mining, etc.

Ecological significance

  • Soil formation is the most important consequence of weathering which is important for the growth and survival of autotrophs, driving the entire food web.
  • Roots of trees get essential minerals from parent rock through microorganisms present in pores, created by weathering.
  • Weathering is important for the modification of landforms, giving rise to different biomes and ecosystems.

Economic significance

  • The formation of soil is the basis of agriculture, which forms the backbone of many world economies.
  • Help in mining and concentration of ores, which has commercial importance.

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