(2)A person working or employed in or in connection with a mine is said to be working or employed—(a)“below ground” if he is working or employed—(i)in a shaft which has been or is in the course of being sunk; or(ii)in any excavation which extends below superjacent ground; and(b)“above ground” if he is working in an open cast working or in any other manner not specified in clause (a).
