Glen Canyon Group

Glen Canyon Group Stratigraphic range: Late Triassic–Early Jurassic
Type	Group
Sub-units	(oldest to youngest) Wingate Sandstone, Moenave Formation, Kayenta Formation, Navajo Sandstone

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.

Group rank (alphabetical):

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 1955 by Averitt and others. They assigned the Shurtz Sandstone Tongue (new) and Lamb Point Tongue (new) to the Navajo Sandstone, and Cedar City Tongue (new) and Tenney Canyon Tongue (new) 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 newly the 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 (change not recognized by the USGS). 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 (who also revised the lower contact). Condon modified the areal extent limits in 1992.

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