| Wescogame Formation | |
|---|---|
| Stratigraphic range: Upper Pennsylvanian, [1] | |
 representative Supai Group 'redbeds' (ridgeline extending north from South Rim, Grand Canyon) | |
| Type | Geologic unit |
| Unit of | Supai Group |
| Underlies | Esplanade Sandstone, (4th member)-Supai Group |
| Overlies | Manakacha Formation, (2nd member)-Supai Group-312 Ma |
| Thickness | 200 feet (61 m) max (100–200 ft typical) |
| Lithology | |
| Primary | sandstone, siltstone |
| Location | |
| Region | Colorado Plateau, southwest and south |
| Extent | Grand Canyon, Verde Valley, and basement rocks of Mogollon Rim and central & east-northeast Arizona |
The (Upper) Late Pennsylvanian Wescogame Formation is a slope-forming, sandstone, red-orange geologic unit, formed from an addition of eolian sand,[2] added to marine transgression deposits (siltstones, etc.), and found throughout sections of the Grand Canyon, in Arizona, Southwest United States. It is one of the upper members of the Supai Group 'redbeds' (member three of four major units), with the Supai Group found in other sections of Arizona, especially in the Verde Valley region, or as a basement unit below the Mogollon Rim, just eastwards or part of the basement Supai Group of the southwest & south Colorado Plateau.
Coeval units of Wescogame Formation and the Supai Group are replaced by geologic units formed from geology deposited in relationship to the former basin to the south-southeast in Arizona, the Pedregosa Basin, of the Pedregosa Sea, which extended northeast to the Verde Valley region, and the earlier deposition of the red rock sandstone of the Schnebly Hill Formation, of the Sedona, Arizona region, (Oak Creek Canyon, Sycamore Canyon, and other related sub-regions).