Glen Canyon Group facts for kids

The Glen Canyon Group is a special collection of rock layers found in the western United States. It stretches across states like Nevada, Utah, northern Arizona, northwestern New Mexico, and western Colorado. Sometimes, people in Colorado and Utah call it the Glen Canyon Sandstone.

This group is made up of four main rock formations. From the oldest to the youngest, they are the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. These rock layers were formed a very long time ago, during the Late Triassic and Early Jurassic periods. This means they are from the time when dinosaurs roamed the Earth! The boundary between the Triassic and Jurassic periods is actually found within the Wingate Sandstone layer. The very top of the Glen Canyon Group is believed to be from the Toarcian stage of the Early Jurassic.

These rocks are an important part of the Colorado Plateau and the Basin and Range areas, showing us what the Earth was like millions of years ago.

The Rock Layers of Glen Canyon Group

The Glen Canyon Group is like a stack of different rock types. Each layer tells a story about the ancient environment.

Key Formations

Here are the main rock layers that make up the Glen Canyon Group:

• Kayenta Formation (found in Arizona, Colorado, Utah)
• Moenave Formation (found in Arizona, Nevada, Utah)
• Navajo Sandstone (found in Arizona, Colorado, New Mexico, Utah)
• Wingate Sandstone (found in Arizona, Colorado, New Mexico, Utah)

These formations are recognized by scientists, including the U.S. Geological Survey (marked with an asterisk * above).

How Scientists Studied These Rocks

Scientists have been studying the Glen Canyon Group for many years to understand its history.

Naming the Group

The Glen Canyon Group was named in 1931 by two scientists, Gregory and Moore. They named it after the amazing rock walls found in Glen Canyon along the Colorado River. These walls are in Coconino County, Arizona and San Juan County, Utah. Other scientists like Gilluly and Reeside had looked at these rocks even earlier. Over the years, many geologists have studied and updated our understanding of these rock layers. They have identified new parts of the formations and refined their ages.

Where You Can Find These Rocks

The Glen Canyon Group is found in several large geological areas across the western U.S.

Geologic Regions

You can find these rocks in places like:

• Black Mesa Basin
• Great Basin province
• Green River Basin
• Paradox Basin
• Piceance Basin
• Plateau sedimentary province
• San Juan Basin
• Uinta Uplift

Dinosaurs and Ancient Life

The Glen Canyon Group is famous for the prehistoric animals found within its layers, especially dinosaurs! Scientists have found both bones and footprints (tracks) of dinosaurs in these rocks.

Dinosaur Discoveries

• In the Wingate and Moenave formations, most of the dinosaur finds are tracks. These tracks show us where dinosaurs walked millions of years ago.
• The Kayenta Formation is a treasure trove of dinosaur bones. Here, scientists have found different types of meat-eating dinosaurs called theropods, like Dilophosaurus and "Syntarsus" kayentakatae. They've also found plant-eating dinosaurs like the Sarahsaurus and armored dinosaurs such as Scelidosaurus and Scutellosaurus.
• The Navajo Sandstone has also given us some dinosaur bones, including the theropod Segisaurus and a plant-eater similar to Ammosaurus. Dinosaur tracks are also common in this formation.

These fossils help us learn about the amazing creatures that lived in this region during the Triassic and Jurassic periods.

Images for kids

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  The amazing rock layers of southeastern Utah, including the Navajo Sandstone, Kayenta Formation, and Wingate Sandstone.

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  A cool alcove (a natural hollow) in the Navajo Sandstone near Moab, Utah.