Undiscovered unit regional resources of Gondwana coals in India

Abstract

A parameter called Undiscovered Unit Regional Resources was formulated and studied for the Gondwana coal resources of India with a view to developing a quick method of estimating undiscovered mineral resources of a region superior to that of Unit Regional Value and Unit Regional Weight. Unit Regional Value and Unit Regional Weight have been used for the evaluation of undiscovered mineral resources of a region, but they give only a broad outlook and can sometimes lead to biased conclusions, particularly over small regions. Weighted Unit Regional Weight for a mineral or minerals based on the area of exposure of the relevant geological formation (s), together with the Unit Regional Reserves computed from already identified reserves yields a measure of greater accuracy in the form of Undiscovered Unit Regional Resources. The Undiscovered Unit Regional Resources of Gondwana coals in India were evaluated for different coal-bearing states of India taking West Bengal as standard, since the Ranigunj coalfield, the only producing coalfield in West Bengal, was found to have reached stage II of the economic life and could be considered as well developed in regard to coal exploitation. The study reveals that Undiscovered Unit Regional Resources give a more reliable estimate of the undiscovered resources of Gondwana coals in the different states of India than Unit Regional Weight and consequently shifts the priority of exploration. The Unit Regional Weight method highly underestimates the total undiscovered coal resources of India at less than 10 billion tonnes, which is very small compared to the already identified reserves of 157.4 billion tonnes.