Which one of the following is the appropriate reason for considering the Gondwana rocks as most important of rock systems of India?
A
More than 90% of limestone reserves of India are found in them
B
More than 90% of India's coal reserves are found in them
C
More than 90% of fertile black cotton soils are spread over them
D
None of the reasons given above is appropriate in this context
Correct Answer: Option B
Explanation
1. The question asks for the appropriate reason why Gondwana rocks are considered the most important rock systems of India.
2. The Gondwana rock system dates back to the Carboniferous period and later eras.
3. These formations are particularly significant because they contain the vast majority of India's coal reserves. Estimates suggest that more than 90% (often cited as around 98%) of India's total coal reserves are found within the Gondwana formations, particularly in the Damodar, Mahanadi, Godavari, and Wardha valleys.
4. Option A is incorrect; major limestone reserves are found in various other formations (like Vindhyan).
5. Option C is incorrect; fertile black cotton soils are primarily derived from the weathering of Deccan Trap basalts, a different geological formation.
6. Therefore, the primary importance of the Gondwana rocks lies in their massive coal deposits.