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

The correct answer is Option 2

Key Points

• ​Black cotton soil in India is the result of weathering of fissure volcanic rock (basalt), primarily from the Deccan Trap region. Hence, option 2 is the correct answer.
• Black Soil:
  • ​Black cotton soil, also known as Regur soil, is a type of soil famous for its high clay content, moisture retention, and dark color.
  • It is rich in iron, lime, calcium, magnesium, and potash but poor in nitrogen and phosphorus.
  • In general, black soils of uplands are of low fertility while those in the valleys are very fertile.
  • The black colour is due to the presence of a small proportion of titaniferous magnetite or iron and black constituents of the parent rock.
  • The black soil is highly retentive of moisture. It swells greatly on accumulating moisture.