Glen Canyon Group


The Glen Canyon Group is a geologic group of formations that is spread across the U.S. states of Nevada, Utah, northern Arizona, north west New Mexico and western Colorado. It is sometimes called the Glen Canyon Sandstone in Colorado and Utah. There are four formations within the group. From oldest to youngest, these are the Wingate Sandstone, Moenave Formation, Kayenta Formation, and Navajo Sandstone. Part of the Colorado Plateau and the Basin and Range, this group of formations was laid down during the Late Triassic and Early Jurassic, with the Triassic-Jurassic boundary within the Wingate Sandstone. The top of the Glen Canyon Group is thought to date to the Toarcian stage of the Early Jurassic.
Asterisks below indicate usage by the U.S. Geological Survey.

Subunits

Group rank :
There is no designated type locality for this group. It was named by Gregory and Moore in 1931 for exposures in walls that form the Glen Canyon of the Colorado River in Coconino County, Arizona and San Juan County, Utah. An overview of the group was given three years before by Gilluly and Reeside. Baker revised the work and named the Kayenta Formation in 1936. The work was revised again in 1955 by Averitt and others. They assigned the Shurtz Sandstone Tongue and Lamb Point Tongue to the Navajo Sandstone, and Cedar City Tongue and Tenney Canyon Tongue to the Kayenta Formation. In 1957 Harshbarger and others created an overview and revision that assigned the Moenave Formation and divided the Wingate Sandstone into the newly named Rock Point and Lukachukai members. The group's age was modified by Lewis and others in 1961 and the upper contact was revised by Phoenix in 1963. Poole and Stewart attempted to reduce the group's rank to a formation they called the Glen Canyon Sandstone in 1964. Areal extent limits were revised by Wilson and Stewart in 1967 and again by Green in 1974. Peterson and Pipiringos revised the upper contact and created an overview in 1979. In 1989 the age of the group was modified by Padian and separately by Dubiel. Condon modified the areal extent limits in 1992.

Places found

Geologic Province:
Prehistoric animals from the various formations of the Glen Canyon Group include several types of dinosaurs, known from both skeletal remains and tracks. Dinosaur finds in the Wingate and Moenave formations are presently almost entirely tracks. The Kayenta Formation has a diverse skeletal fauna including the theropods "Syntarsus" kayentakatae and Dilophosaurus, the prosauropod Sarahsaurus, an unnamed heterodontosaurid, and the armored dinosaurs Scelidosaurus and Scutellosaurus. The Navajo Sandstone has body fossils of the theropod Segisaurus and an Ammosaurus-like prosauropod, and tracks.

Works cited