asked the Secretary of State for Energy what estimates have been made of coal reserves in Scotland which have been sterilised by (a) abandonment of small mines and (b) closure of uneconomic mines; and what proportions these constitute of overall coal reserves in Scotland.

Some 1,300 million tons of coal reserves in Scotland have been abandoned as a result of colliery closures since 1947. None of this tonnage was economically workable. Economically workable reserves in Scotland are currently assessed at 226 million tons. I have no information on the effect of closure of small mines not in the ownership of the National Coal Board.