The Grand Staircase is an immense sequence of sedimentary rock layers. It comprises six thousand vertical feet of alternating cliffs and slopes that stretch north from the Grand Canyon through Zion National Park and into Bryce Canyon National Park. The western border is the Hurricane Cliffs, and the eastern border is East Kaibab monocline, commonly known as The Cockscomb. The concept of “Grand Staircase” is believed to originate with geologist Clarence Dutton, who in the 1870s first conceptualized this region as a huge stairway ascending out of the bottom of the Grand Canyon northward with the cliff edge of each layer forming giant steps. Dutton divided this layer cake of Earth history into five steps that he colorfully named Pink Cliffs, Grey Cliffs, White Cliffs, Vermilion Cliffs, and Chocolate Cliffs. Each “stair” can rise as high as 2000 feet, and each “step” can be as wide as 15 miles.
The Grand Staircase is unique because it shows layer after layer of sedimentary rock one on top of another. While most sedimentary rock depositions have been obscured by the rise and fall of mountains, destruction by erosion, or other forces, the Grand Staircase demonstrates more than 600 million years of earth history that can be easily viewed. It also encompasses three national parks: Bryce Canyon, Zion, and Grand Canyon. The continuity of the staircase is evident: Kaibab Limestone is the newest and highest layer of the Grand Canyon, but is the lowest and oldest layer of Zion National Park to the northwest. Likewise, the Dakota Sandstone is the is the newest and highest layer of Zion National Park, but is the lowest and oldest layer of Bryce Canyon National Park to the northeast.
The Grand Staircase was formed over millions of years as sediment was deposited by warm, shallow seas. Later, these layers underwent 5000 to 10,000 feet of uplift starting about 66 million years ago. This increased the ability of various river, most notably the Colorado, to cut channels which later formed many of the valleys and canyons. The Grand Staircase is so large that most of the time the various layers are hidden by the earth’s curvature. Two locations; Yovimpa Point in Bryce Canyon, and the north slope of the Kaibab Plateau (this earthcache) allow multiple layers to be seen in a single view.
To log this earthcache, go to the posted coordinates and view the Grand Staircase to the north. Then send me an email or a message with answers to the questions below. You do not have to wait for me to respond in order to log the find. I will contact you if I have issues with your answers.
1. How many “steps” can you see from this location?
2. What color are they
3. Which layers do you think you see based on your answers to questions 1 and 2?
4. Explain why the Kaibab Plateau is higher than steps to the north, even though it lies on the Kaibab Sandstone, which is beneath these “steps.”
5. Bonus Question (Not Required): Which steps make up the bulk of the formations in Zion and Bryce Canyon National Parks?
6. OPTIONAL: Post a picture of your party with the Grand Staircase in the background.
Sources (including posted diagrams):
1. “What is the Grand Staircase?” Public Information Series 64, Utah Geologic Society, http://geology.utah.gov/online/pdf/pi-64.pdf
2. “Grand Staircase”, National Park Service, http://www.nps.gov/brca/naturescience/grandstaircase.htm
3. “Grand Staircase”, Wikipedia http://en.wikipedia.org/wiki/Grand_Staircase
This Earthcache is placed with the permission of the Kaibab National Forest, Fredonia Ranger District. My sincere appreciation to them for their assistance and support.