Tertiary coal
Topic: Energy Resources of India: Conventional and Non-conventional · NCERT: Class 10, Ch 5 "Minerals and Energy Resources"; Class 12, Ch 5 "Mineral and Energy Resources"
Meaning
Tertiary coal is younger coal. It is about 15–60 million years old, and Class 10 NCERT gives about 55 million years. It has less carbon and more sulphur than the older Gondwana coal, so it is lower in quality and more polluting when burnt. It makes up only a small share of India's reserves and is found mainly in the North-East. In Meghalaya, it was dug from narrow, family-dug tunnels called rat-hole mines. The National Green Tribunal (NGT) banned this method in 2014.
Example
Tertiary coalfields include Darangiri, Cherrapunji, Mewlong and Langrin (Meghalaya), Makum, Jaipur and Nazira (upper Assam), Namchik-Namphuk (Arunachal Pradesh) and Kalakot (Jammu and Kashmir).
Don't confuse with
- Gondwana coal: Gondwana coal is about 250–300 million years old and makes up about 98 per cent of reserves. It is mostly bituminous and lies in the Damodar, Sone, Mahanadi and Godavari valleys.