Question

which is the geological age of coal found in north east india ?

Answer 1

Its the Tertiary age, which is about 55 million years old.

Answer 2

There are three separate geological horizons. In Meghalaya, two seams are from the lower eocene period. In upper Assam, one seam has been found which is of the oligocene period. The formations are called Jaintia Formation and Barail Formation respectively. Though from the tertiary age, these coal deposits are of a higher rank than many deposits of later periods. By nature, they are advanced types of meta-lignite approaching bituminous coals in their in composition.