Abstract
The feasibility of using Permian bedded salts in the Palo Duro Basin of the Texas Panhandle for nuclear waste disposal is in part dependent on maintaining the integrity of the repository throughout a geologically significant length of time, possibly as long as 250,000 years. Geologic processes such as, scarp retreat erosion, and denudation decrease the thickness of protective overburden above an underground repository. Bedded salts that may be suitable for a waste disposal site occur primarily beneath the Southern High Plains. Eastward of the High Plains salts beneath the Caprock Escarpment and the adjacent Rolling Plains are undergoing dissolution and are probably not suitable as disposal sites. The bedded salts beneath the Southern High Plains, where they are adjacent to the Caprock Escarpment, may eventually be affected by erosional processes as the Caprock Escarpment retreats westward and as the Rolling Plains are denuded. Regional rates of westward retreat of the escarpment were determined for time periods that range from 7,900 to 3,000,000 years and vary from 11 to 18 cm/yr (4.3 to 7.1 in./yr). Surface denudation rates are available for 19 drainage basins on the Rolling Plains and range from 0.50 to 2.97 mm/yr (0.02 to 0.118 in./yr). Under present land use and climatic conditions the erosion and denudation along the Caprock Escarpment and on the Rolling Plains are proceeding at near maximum rates.
