These strata attest to a flat, arid paleoenvironment along the western margin of Pangaea with intermittent marine transgressions from the Panthalassa Ocean. Conditions there may have been analogous to the modern-day Persian Gulf coast of the Arabian Peninsula. As sea levels rose and fell over the course of many millennia, so too did the depositional environment change, resulting in repeating sequences of rock strata distinctive to the late paleozoic. In periods of high sea-level, limestone and shale were deposited, while periods of low sea-level resulted in the deposition of red and green clays and paleosols, giving the exposures at the spillway canyon a colorful layer cake appearance.