Civil Services Prep

Prelims 2021 · Geography · Question 64

The black cotton soil of India has been formed due to the weathering of

  1. brown forest soil
  2. fissure volcanic rock
  3. granite and schist
  4. shale and limestone

Answer

fissure volcanic rock

  • (a) Brown forest soil: This is itself a soil type, not the parent rock for black cotton soil. Verdict: Incorrect.
  • (b) Fissure volcanic rock: Black cotton soil (regur) is mainly formed by weathering of Deccan Trap basalt, a fissure volcanic rock. Verdict: Correct.
  • (c) Granite and schist: These rocks are more commonly associated with red and other residual soils, not typical black cotton soil formation. Verdict: Incorrect.
  • (d) Shale and limestone: Black soil may occur over some calcareous material locally, but its classic and major origin in India is basaltic lava rock. Verdict: Incorrect.
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