The Grand Staircase in Arizona and Utah
March 04, 2019
Photographer: Patti Weeks
Summary Author: Patti Weeks
The Grand Staircase is a geologic phenomenon consisting of tilted sedimentary rock layers that cover millions of acres of land, stretching more than 100 mi (162 km) northward from the Grand Canyon National Park in northern Arizona to Bryce Canyon National Park in southern Utah. The staircase image was first conceptualized by geologist Clarence Dutton in the 1870s. It's actually a series of cliffs (risers) and plateaus and benches (steps). The cliffs are named for their general color. In order of ascending elevation, they include chocolate, vermilion, white, gray and pink. The staircase’s gentle downward tilt toward the north has exposed the softer rock of each layer to erosion, thus displaying its stair-step appearance.
This magnificent landscape has evolved over millions of years from rising seas, shifting desert sands, meandering rivers, lakes, the tectonic uplift of the Colorado Plateau and continual erosion. The rock layers range in age from approximately 270 million years in the Permian Period at the North Rim of the Grand Canyon to 50 million years in the Cenozoic Era at Bryce Canyon. It's interesting to note that there are intervals of million-year gaps in the geologic history of the staircase (unconformities), most likely due to complete erosion of the missing strata.
The top photo is a panorama of the Grand Staircase taken from the LeFevre Overlook on the Kaibab Plateau about 50 mi (80 km) north of the Grand Canyon’s North Rim. From this viewpoint looking north, one can envision a span of nearly 165 million years of geologic activity and view the south-facing escarpments of the staircase. The inset photo is a close-up of a portion of the Grand Staircase, showing the five main cliff layers.
Click here to see a diagram published by the Zion Natural History Association that illustrates a cross section of the formations. Click here to see a simulation of an overhead view of the Staircase's geologic layers. Photos taken November 4, 2018.
Photo Details: Top - Camera: SONY DSC-RX100M4; focal length: 25.7mm; aperture: f/5.6; exposure: 1/800 second; ISO 125. Bottom - Camera: SONY DSC-HX400V; focal length: 83.53mm; aperture: f/5.6; exposure: 1/640 second; ISO 80.