Salt deposits of the Paradox Basin, southeast Utah and southwest Colorado

Thick salt deposits are present in the Paradox Member of the Hermosa Formation [Middle Pennsylvanian]. Data suggest that the original thickness was from 5,000 to 6,000 feet, but locally, deformation and flow have resulted in thicknesses as great as 14,000 feet. Each salt bed is part of a series of evaporite cycles showing lateral and vertical facies changes. Varve counts in the salt beds give an indication of deposition rates of time-equivalent carbonate rocks. Black shales interbedded in the salt suggest euxinic conditions. Many of the salt anticlines in the basin were formed along trends of originally thick salt beds, and upward growth of these anticlines possibly began during the late stages of salt deposition.