Straddling the 4 corners region is a massive geologic province known as the Colorado Plateau. Varying from 5 to 10,000 feet in elevation the region covers an area larger than the state of New Mexico, and is composed of thick horizontal layers of sedimentary rock . Terrain here is flat compared with Basin and Range country to the west and the Rocky Mountains to the east. Yet wind and water have whittled Plateau rock into dramatic cliffs and steps as well as fanciful domes, towers, turrets, and arches. The Plateau is dissected by the Colorado River and its tributaries exposing a deep and colorful geologic history. A predominance of red bed deposits in the central area of the Plateau has prompted the nickname “red rock country.”
So what’s behind the spectacular hues for which Utah is so famous? The color of rock is primarily influenced by trace minerals. The red, brown, and yellow colors so prevalent in southern UT result from the presence of oxidized iron–that is iron that has undergone a chemical reaction upon exposure to air or oxygenated water. The iron oxides released from this process form a coating on the surface of the rock or rock grains containing the iron.
Just think of what happens to a nail when you leave it outside. Upon prolonged exposure, the iron in the nail oxidizes and rust is formed as a coating on the surface of the nail. So basically what we have in red rock country is a lot of rusting sandstones and shales. Hematite is an especially common mineral form of iron oxide in Utah, the name coming from the Greek word “heama” or red blood. It only takes a tiny bit of hematite make a lot of red rock.
Geologists refer to rock layers of similar composition and origin within a given geographic area as “formations.” Certain formations in Utah are especially known for their beautiful reds or pinks. The Permian Period gave us Organ Rock shale which caps the buttes and pinnacles of Monument Valley. The deep ruddy browns of the Moenkopi formation were formed in the Triassic. In the early Jurassic, eastern Utah was a vast sea of sand with wind-blown dunes. These dunes became the red bed deposits of the Wingate Formation which today forms massive vertical cliffs. Entrada sandstone, from the late Jurassic, forms the spectacular red, slickrock around Moab.
Well anyway, now you know what I’m thinking of when I hear Utah referred to as a Red State. I’m picturing the extraordinary beauty of the red, salmon and rust- brown rocks that help to form the massive geologic layer cake in the south and east of our state.
For Wild About Utah and Stokes Nature Center, I’m Holly Strand.
Photo: Courtesy NPS.gov: http://www.nps.gov/brca/
Text: Stokes Nature Center: Annalisa Paul
Sources & Additional Reading
Chan,Marjorie A. and William T. Parry Rainbow of Rocks . Public Information Series 77. Utah Geological Survey. http://geology.utah.gov/online/pdf/pi-77.pdf (Accessed July 2008)
Geology Underfoot in Southern Utah by Richard L. Orndorff, Robert W. Wieder, and David G. Futey, Missoula, MT Mountain Press Publishing Company, 2006, http://mountain-press.com/item_detail.php?item_key=366
Chronic, Halka. Roadside Geology of Utah. Missoula, MT Mountain Press Publishing Company, 1990 http://mountain-press.com/item_detail.php?item_key=48
Fillmore, Robert, The Geology of the Parks, Monuments and Wildlands of Southern Utah, University of Utah Press, 2000, http://content.lib.utah.edu/cdm4/item_viewer.php?CISOROOT=/upcat&CISOPTR=1328
“A roadrunner up in a tree? Couldn’t be!” was the comment I got upon describing this unusual sighting to some BLM employees in St. George, Utah. But sure enough, there it was, most likely a juvenile trying out it’s new wings as it’s lesser siblings scrambled through the desert scrub near a wet hollow. I too was amazed to see this quirky bird in a tree, but then stories I had accumulated from those who have lived in roadrunner territory bore testimony to its strange ways.
Their ungainly and rather comical appearance, combined with their eccentricities, have endeared them to many, and find myself no exception. And yes, as you have heard, they are very quick on their feet attaining sustained ground speeds of 17 MPH, not quite as fast as Canis Latrans, the wily coyote. Another peculiarity- for whatever reason, they have a propensity for running into buildings, perhaps hoping to corner their prey.
A member of the cuckoo family, the Roadrunner is uniquely suited to the hot desert environment found in southern Utah. This is because of a number of physiological and behavioral adaptations. Its carnivorous habits offer it a large supply of very moist food. It reabsorbs water from its feces before excretion. A nasal gland eliminates excess salt instead of using the urinary tract like most birds. An it reduces its activity 50% during the heat of midday.
Its extreme quickness allows the roadrunner to snatch a humming bird or dragonfly from midair. Snakes, including rattlers, are another favorite food. Using its wings like a matador’s cape, a roadrunner snaps up a coiled rattlesnake by the tail, cracks it like a whip and repeatedly slams its head against the ground until lifeless. It then swallows its prey whole, but is often unable to swallow the entire length at one time. This does not stop the Roadrunner from its normal routine. It will continue to meander about with the snake dangling from its mouth, consuming another inch or two as the snake slowly digests.
I can scarcely wait for my next encounter with the roadrunner!
Photo: Courtesy and Copyright 2013 Jeff Cooper Jeff Cooper
Text: Bridgerland Audubon Society: Jack Greene
For More Information:
Desert USA – The Roadrunner, http://www.desertusa.com/road.html (accessed 22 July 2008)
Animal Diversity, University of Michigan Museum of Zoology, Geococcyx californianus –
greater roadrunner, http://animaldiversity.ummz.umich.edu/site/accounts/information/Geococcyx_californianus.html