Paradox Formation

In geology, the Paradox Formation Is a Pennsylvanian age formation which consists of abundant evaporites with lesser interbedded shale, sandstone, and limestone. The evaporites are largely composed of gypsum, anhydrite, and halite.

The formation is exposed in anticlines in eastern Utah and western Colorado.

The Paradox is part of the Hermosa Group which is overlain by the Permian Cutler Group.

It occurs in the Black Mesa, San Juan and Paradox Basins in outcrop and subsurface in southwestern Colorado, southeastern Utah, northeastern Arizona and northeastern New Mexico.

...
Wikipedia