As used in this subpart, the term:

Combined hydrocarbon lease means a lease issued in a Special Tar Sand Area for the removal of any gas and nongaseous hydrocarbon substance other than coal, oil shale or gilsonite.

Oil and gas lease means a lease issued in a Special Tar Sand Area for the exploration and development of oil and gas resources other than tar sand.

Special Tar Sand Area means an area designated by the Department of the Interior's Orders of November 20, 1980 (45 FR 76800), and January 21, 1981 (46 FR 6077), and referred to in those orders as Designated Tar Sand Areas, as containing substantial deposits of tar sand.

Tar sand means any consolidated or unconsolidated rock (other than coal, oil shale or gilsonite) that either:

(1) Contains a hydrocarbonaceous material with a gas-free viscosity, at original reservoir temperature greater than 10,000 centipoise, or

(2) contains a hydrocarbonaceous material and is produced by mining or quarrying.

Tar sand lease means a lease issued in a Special Tar Sand area exclusively for the exploration for and extraction of tar sand.