Grand Canyon Supergroup

The Grand Canyon Supergroup uncomformably overlies the Vishnu Basement Rocks but was never subjected to metamorphism.

The majority of the Grand Canyon Supergroup geologic members are found in the south and southwest stretch of the Colorado River starting from Marble Canyon, traverses the southeast perimeter of the Kaibab Plateau, and flows northeasterly entering Granite Gorge and regions of the Vishnu Basement Rocks.

Other sections of the Unkar Group reappear downstream due to the general faulting of the Grand Canyon.

The Isis Temple and Cheops Pyramid formation is a part of the Shinumo Quartzite 'island' and made up of the bottom three Unkar Group members.

The Tapeats is a thin cliff-former unit found along Granite Gorge and its side canyons forming a flat surface in locales not dramatically affected by faulting, up-warping (domes), or down-warping.

The Isis Temple with Cheops Pyramid formation contains the bottom three members, a virtual quartzite 'mountain island' in the Tapeats Sea.

Even further to the extreme northeast, at the Marble Canyon (Marble Platform), four parallel faults (2 sets of 2 – including the Eminence Fault), run parallel to the side of the Paria Plateau, striking northeasterly, resulting in the Colorado River's sharp turn to the southwest.

A view looking north. Unkar Group units lying below the Isis Temple /Cheops Pyramid landforms:
Shinumo Quartzite cliffs (lower part shown on top of photo), above
Hakatai Shale (red-orange-purple slopes), above
Bass Formation (finely-layered, dark slopes), sitting on top of (base units).
Vishnu Basement Rocks (black stratum) within the Granite Gorge and side canyons.
Geologic stratigraphic column of strata exposed in and near the Grand Canyon showing stratigraphic units and major unconformities
Stromatolite from the Grand Canyon Supergroup exhibit at Trail of Time
Basalt dike in orange-red Hakatai Shale along Colorado River at Hance Rapid, river mile 76.5, Grand Canyon.
Isis Temple and Cheops Pyramid on a fault-block (horst), sitting on "island" of Shinumo Quartzite, of the Unkar Group. Bottom of the Unkar above Granite Gorge, and Vishnu Basement Rocks. (3.5 mi by 2.0 mi block)
At Apollo Temple landform, the Cambrian Tapeats Sandstone lies above the angular Great Unconformity with strata of the Chuar Group, Nankoweap Formation (the striped), Cardenas Basalt (the dark), and Dox Formation (red) below. (The lower strata are dipping to the right (east), as well as a total regional-dip to the northeast.)