(a) Unless otherwise specified in the leasing notice, a lease for OCS minerals shall include rights to all minerals within the leased area except the following;

(1) Minerals subject to rights granted by existing leases;

(2) Oil;

(3) Gas;

(4) Sulphur;

(5) Minerals produced in direct association with oil, gas, or sulphur;

(6) Salt deposits which are identified in the leasing notice as being reserved;

(7) Sand and gravel deposits which are identified in the leasing notice as being reserved; and

(8) Source materials essential to production of fissionable materials which are reserved pursuant to section 12(a) of the Act.

(b) When an OCS mineral lease issued under this part limits the minerals to which rights are granted, such lease shall include rights to minerals produced in direct association with the OCS mineral specified in the lease but not the rights to minerals specifically reserved.

(c) The existence of an OCS mineral, oil and gas, or sulphur lease shall not preclude the issuance of a lease(s) for other OCS minerals in the same area. However, no OCS mineral lease shall authorize or permit the lessee thereunder to unreasonably interfere with or endanger operations under an existing OCS mineral, oil and gas, or sulphur lease.