Nuclear-waste repository impaired by effects of sub-surface salt dissolution

Thirty alkaline lake basins are underlain by Permian salt in West Texas-eastern New Mexico. Early workers thought the basins were created by solution of Permian salt, causing surface collapse. It wasn't until studies by Gustavson and others (1980-85) that salt dissolution beneath several basins was confirmed. Study of alkaline lake basins 240 km south of the main area worked by Gustavson and others (1980-85) shows basins associated and not associated with salt dissolution. Basins associated with salt dissolution are often underlain by Cretaceous formations which are either horizontal or displaced. Thus, evidence indicates many of the large lake basins are antecedent to salt dissolution, that salt dissolution results from infiltration of lake water, and that a certain amount of dissolution occurs before propagation of the cavity to surface. Areas of unusually thick Cretaceous rocks around several lake basins in the central Southern High Plains and unusually thick sections of Tertiary Ogallala in the Northern High Plains indicate regional dissolution of Permian salt beds prior to Cretaceous deposition. Therefore, dissolution of Permian salt in West Texas has been of long-term, regional extent, and formation of sinks, faults and the solute discharge of streams east of the Southern High Plains indicates salt more » dissolution continues. It therefore follows that the geologic integrity of any high-level nuclear-waste repository site in the Permian salt beds may be seriously impaired, and that the geologic suitability of bedded salts for high-level nuclear-waste storage anywhere by seriously questions. « less