Bryce Canyon National Park

Geology
Gorp.com
Bryce Canyon National Park
Bryce Canyon National Park (Photodisc/Getty)

What has powerfully shaped the landscape here is what has also rendered it less than usable for most human purposes: water. What you see at Bryce Canyon is the product of erosion, and in Bryce Canyon erosion is caused by water—as rain, snow, and ice. It is not caused by wind, a common misconception about how Bryce Canyon was formed. Practically all of southwest Utah is in fact a result of the eternal cycle of uplift and erosion. Right now the land is on top of the struggle. This region began rising about 13 million years ago until parts of it were more than three kilometers (two miles) above sea level. Yet the red rocks you look at here were deposited by vast lakes once covering this area. In earlier times dinosaurs tramped its swamps, foraging tons of plant foods, and left their own story in fossil bones. The topography in this region rises to the north, creating a staircase effect. Descending southward from Bryce Canyon along the staircase, the exposed geological formations become progressively older.

Bryce Canyon is not a canyon at all, but a spectacular amphitheater carved by erosion in the 50- to 60-million-year-old rocks of the Pink cliffs. These cliffs are the upper most step in the Grand Staircase that rises to the north between Grand Canyon and Bryce Canyon National Parks. The Staircase is a series of cliffs, all retreating to the north as the superimposed rock layers of southern Utah are eroded. Some layers formed at the bottom of ancient seas, others on the coastal plains adjacent to the shifting margins of the sea. The layers were uplifted and are now being eroded by the action of water.

The capstone of the Grand Staircase is the Pink Cliffs (elevation 2,800 meters-9,100 feet)—ancient lake deposits once more than 600 meters (2,000 feet) thick but now reduced in thickness by erosion 250 to 400 meters (800 to 1,300 feet). Look south from Yovimpa Point in the southern part of Bryce Canyon National Park and you will see the Grand Staircase stretching backward in time. You will be standing on the upper most of five major steps formed by the eroding cliff faces of tilted sedimentary rock layers, each distinctive in character and color. Now, for a panoramic view of the Pink Cliffs themselves, go to Rainbow Point in the park. Their color is due to the presence of iron particles in the rock that oxidize and impart the resulting pigment to the whole formation.

The Grey Cliffs are of such soft stone that their cliff faces are less perpendicular than those of adjacent formations. They were deposited about 120 to 135 million years ago. The rocks of the Grey Cliffs can be seen at the base of Bryce Canyon and are visible along the road between Bryce Canyon and Zion National Parks.

Zion Canyon is incised into the rock of the White Cliffs. Here, the formations range in age from 135 to 165 million years and total more than 670 meters (2,200 feet) in depth. These are the tallest cliffs among the steps of the Grand Staircase. The White Cliffs are really tan in color, but appear white in sunlight. Their elevation above sea level ranges from more than 1,500 to more than 2,100 meters (5,000 to 7,000 feet). See these spectacular cliffs along the road to Grand Canyon.

The Vermilion Cliffs are a brilliant dark red. These vertical cliffs are 165 to 200 million years old and more than 300 meters (1,000 feet) thick. Look for these red rocks at the base of the canyon walls as you walk through Zion and as you drive along the road to the Grand Canyon.

The rocks of the Chocolate, or Belted, Cliffs are older than those of the Vermilion Cliffs. They formed about 200 to 225 million years ago. They average 550 meters (1,800 feet) in thickness. The Chocolate Cliffs are reddish-brown but have belts of other colors running through them. Look for these near the south entrance to Zion National Park.

The southern edge of the Kaibab Plateau is the north rim of the Grand Canyon, and this top edge of the Grand Canyon is the bottom of the Grand Staircase. The Kaibab Limestone is more than 225 million years old, but this formation is one of the youngest you will see when you visit the Grand Canyon.


Published: 5 Sep 2009 | Last Updated: 9 Nov 2011
Details mentioned in this article were accurate at the time of publication

advertisement

Sign up to Away's Travel Insider

Preview newsletter »