The Unkar Group is a sequence of strata of Proterozoic age that are subdivided into five geologic formations and exposed within the Grand Canyon, Arizona...

Unkar Group, which forms the base of Isis Temple, consists of the Shinumo Quartzite, Hakatai Shale, and Bass Formation in descending order. The Unkar...

the eastern Grand Canyon of Arizona. This group comprises the Unkar Group, Nankoweap Formation, Chuar Group and the Sixtymile Formation, which overlie...

shale slopes of the Cambrian Tonto Group, and below that red shale and Shinumo Quartzite of the Proterozoic Unkar Group. Precipitation runoff from Cheops...

underlie the Bass Limestone of the Unkar Group of the Grand Canyon Supergroup and the Tapeats Sandstone of the Tonto Group. These basement rocks have also...

984 ft). In general, the Hakatai Shale and associated strata of the Unkar Group rocks dip northeast (10–30°) toward normal faults that dip 60° or more...

Pennsylvanian-Permian Supai Group. Further down are strata of Mississippian Redwall Limestone, Cambrian Tonto Group, and finally Proterozoic Unkar Group at creek level...

Pennsylvanian-Permian Supai Group. Further down are strata of Mississippian Redwall Limestone, Cambrian Tonto Group, and finally Proterozoic Unkar Group at creek level...

Bass Formation. The Bass Formation is the basal part of the Unkar Group. The Unkar Group is about 1,600 to 2,200 m (5,200 to 7,200 ft) thick and composed...

unconformity between the Tonto Group and the Vishnu Basement Rocks is a nonconformity. The break between the Tonto Group and the Grand Canyon Supergroup...