In which two geological ages did coal occur in India?
In India, coal occured in two geological ages—Gondwana and tertiary deposits.
- Gondwana is a little over 200 million years in age. The major resources of Gondwana coal, which are metallurgical coal, are located in Damodar Valley (West Bengal, Jharkhand). Jharia, Raniganj, Bokaro are important coalfields.
- Tertiary deposits are only 55 million years old. Tertiary coals occur in the north-eastern states of Meghalaya, Assam, Arunachal Pradesh and Nagaland.