(a) that portion of the Lower Churchill Development Area, as described in The British Newfoundland Corporation Limited (Lower Churchill River) Lease Act, 1966-67, that is within the above described area;
(b) areas described in mining leases, mining licences or development licences issued before July 14, 1981 that are within the above described area;
(c) mineral concession areas held by the British Newfoundland Corporation (assigned to Brinex) that are within the above described area; and
(d) the main development area of the Churchill Falls (Labrador) Corporation Limited, as described in The Churchill Falls (Labrador) Corporation Limited (Lease) (Amendment) Act, 1969, that is within the above described area.