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Q120
(IAS/2010)
Geography › Indian Physical Geography › Indian soil types
Answer Verified
When you travel in certain parts of India, you will notice red soil. What is the main reason for this colour ?
Result
Your answer:
—
·
Correct:
C
Explanation
Red soils in parts of India owe their colour to ferric (iron) oxides. Weathering of crystalline rocks leaves iron minerals that, when oxidized to haematite and limonite, coat grains and impart a red hue [1]. Oxidation in aerated conditions promotes formation of these ferric oxides, producing the characteristic red (or yellow when hydrated) colour; reduced conditions turn the colour greenish/grey [2]. Textbooks also note that red soils are deficient in humus and phosphates, so accumulated humus or high phosphate content cannot explain the red colour—rather ferric oxides are the primary cause [3].
Sources
- [1] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 6: Soils > 9. Grey and Brown Soils > p. 12
- [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 6: Geomorphic Movements > Oxidation and Reduction > p. 91
- [3] Geography of India ,Majid Husain, (McGrawHill 9th ed.) > Chapter 6: Soils > 2. Red Soils > p. 10
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