The Kaibab and Toroweap Formations of southwestern Utah contain six members which represent transgressive and regressive cycles. The lowest member of the Toroweap Formation is the Seligman, which contains gypsiferous siltstone in the south and sandstone in the north. It represents a transition from a sabkha in the south to a beach in the north and marks the beginning of a marine transgression. Above the Seligman is the Brady Canyon Member which is a fossiliferous limestone containing broken and rounded fossils deposited in a marine environment. Overlying the Brady Canyon is the Woods Ranch Member consisting of gypsiferous siltstone at the bottom with oolitic fossiliferous limestone near the middle and silty limestone at the top. Its

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depositional environmental interpretation is a sabkha near the bottom, an open marine in the middle, and shallow marine near the top representing a regression, transgression, and regression. The lowermost member of the Kaibab Formation, the Fossil Mountain, is a fossiliferous chert-bearing limestone with whole fossils and was deposited in a low-energy marine environment suggesting a transgression. Overlying the Fossil Mountain Member is the Harrisburg Member which consists of a series of alternating gypsiferous siltstones, dolomites, and limestones interpreted as having been deposited in an environment which fluctuated between a sabkha and shallow, open-marine seas.

Overlying the Harrisburg Member is the discontinuous Rock Canyon Conglomerate. It represents erosion and dissection of the Harrisburg Member and resulted from a major marine regression during Late Permian time.

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