The Late Mississippian-Early PennsylvanianSurprise Canyon Formation is a conglomerate, sandstone, limestone and dark purplesiltstone type formation, occurring as 'channel fill'. The Surprise Canyon Formation was deposited upon a mostly horizontal, much eroded Redwall Limestonesurface, the Redwall originally deposited as marine- limestone, ; when the Surprise Canyon Formation was being deposited, the Redwall Limestone surface existed under karst topography conditions, in a "warm, and humid" -environment. The karst topography created "sinks, caves, and underground channels", and created "deep ravines and stream valleys developed as caverns collapsed". Some valleys probably filled with " 'clayey red-orange soil' similar to that known in the Tropics today." Below the Redwall surface, solution-cavern deposits of the Surprise Canyon, have a Redwall Limestone geologic layer, now expressed above them. The Surprise Canyon Formation is found extensively in regions below Grand Canyon Village, Arizona, South Rim, regions northwest, north, and northeast. It is discontinuous, but is found in geologic sequences below the South Rim, and its various landforms, and also especially at the Inner Gorge in specific landforms that have cliffs, and upper surface platforms of the Redwall Limestone. Example landforms near Grand Canyon Village, are Pattie Butte-, Tower of Set,, and Brahma Temple's southern Redwall Limestone points, Johnson and Sturdevant Points, due east of Isis Temple. Fossils of plant material, marine shells, where some fossils may have been 'derived fossils' from the Redwall Limestone, are found in the formation; also fossil logs, showing the erosion, or valley and canyon topographies and the erosional forces of the time period. Besides the easily recognized locations of the Surprise Canyon Formation on the Redwall Limestone platforms, it is found in more vertical sequences where the lowest Supai Group member, the Watahomigi Formation, major sub-unit 1 of 4, transitions, and sits upon the Surprise Canyon, upon the Redwall Limestone. As stated, the Surprise Canyon in the Grand Canyon Village region is discontinuous, but occurs in all sub-sections, further explaining a many-channeled paleo-surface of the eroding Redwall Limestone. The supplementing, and later hypothesis is that marine conditions, to the west of the proto-North American continent, had created an estuarine region, with accumulations from continental erosion. With apparent uniform thicknesses of the Surprise Canyon, as opposed to a highly variable thickness, near sea-level conditions, and a probable lack of high terrains on the eroding Redwall surface, these are all suggested factors leading to creation of the thin, discontinuous accumulations, and thin lenses, that appear regionally extensive in the estuary region. The Redwall Limestone member itself is massive, and is very continuous, and is found as a base geologic unit for much of Grand Canyon; it also forms the walls of Marble Canyon in the northeast canyon, where the Colorado River makes its entrance, about 30-mi, north-northeast of the Grand Canyon Village region, South Rim.
In the central Grand Canyon, the Surprise Canyon and Temple Butte formations have equivalent thicknesses, averaging 75–150 ft. The major difference between the two is that the Devonian Temple Butte was deposited in the western Grand Canyon, and regions in Nevada, on the passive margin of the North American proto continent; the continental shelf was subsiding, and the Temple Butte reached a thickness of about in west Grand Canyon at the Grand Wash Cliffs, and even greater thicknesses ) in the Frenchman Mountain region of Nevada. Both the Temple Butte and Surprise Canyon Formations were deposited on erosional unconformities, on karst terrains of the Muav and Redwall limestones. The following is a chart of the Surprise Canyon Formation, Redwall Limestone, Temple Butte Formation, and other related geologic units across the Colorado Plateau:
