The Paradox basin (Colorado Plateau province) is an intracratonic depression developed on continental crust. The elongate northwest-trending rhombic-shaped basin of Middle Pennsylvanian age is bounded on the northeast by the Uncompahgre-San Luis segments of the Ancestral Rocky Mountains and on the southwest by the less prominent Four Corners lineament. The basin sagged along intersecting basement fractures by strong east-west extension during Middle Pennsylvanian time. The master fracture system was the northwest-trending Olympic-Wichita structural lane.

Oblique divergent strike-slip faulting along the Uncompahgre-San Luis segment created a tension-releasing bend where the Paradox pull-apart

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basin nucleated and subsequently developed throughout Middle Pennsylvanian time. Smaller subbasins developed by orthogonal spreading along intersecting northeast-trending transform faults, where the rate of basin-floor subsidence was related to combinations of normal and strike-slip faulting. The greater Paradox basin was episodically deepened during Middle Pennsylvanian time by rejuvenated extensional basement faulting. Vertical displacement was greatest along the Uncompahgre front, which caused tilting of the basin and deposition of an asymmetrically thick sedimentary sequence.

By mid-Desmoinesian time, the rate of divergent strike-slip faulting slowed considerably. Folds caused by minor wrench movements provided shoaling conditions along the southwest shallow carbonate shelf where porous algal mounds developed. Meanwhile, continued tectonic movement and space-reduction of the basin floor may have triggered salt flowage and diapirism in the deep eastern pull-apart trough. As wrench tectonism diminished from late Desmoinesian through Early Permian time, the eastern portion of the basin continued to subside and was filled with marine and continental sediments.

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