Erosion Made My Favorite Places

Erosion Made My Favorite Places: Bluff of Little Flat Top Courtesy and Copyright Shannon Rhodes, photographer
Bluff of Little Flat Top
Courtesy and Copyright Shannon Rhodes, photographer

Muddy Creek Courtesy and Copyright Shannon Rhodes, photographer Muddy Creek
Courtesy and Copyright Shannon Rhodes, photographer

North Fork Pleasant Creek Terracing Courtesy and Copyright Shannon Rhodes, photographer North Fork Pleasant Creek Terracing
Courtesy and Copyright Shannon Rhodes, photographer

Blackburn Draw Courtesy and Copyright Shannon Rhodes, photographer Blackburn Draw
Courtesy and Copyright Shannon Rhodes, photographer

Brendan Wenzel says the inspiration for his picture book “A Stone Sat Still” was a familiar boulder nestled in a tidal inlet near his family’s home. This stone was a dining place, a perch, a tool, and a landmark, but dependably there day after day, year after year. When I shared this book as a writing workshop launch with fellow educators, it drew recollections of sandboxes, rock collections, garden pavers, mantle stones, stacked-stone cairns keeping us on the right trail, and deeper connections to fathers. I wrote about how stones definitely don’t sit still when I am around. When my father would take us fishing, my brothers and I would most likely be skipping every flat rock we could find across the lake’s surface instead of manning our poles. Even now I can’t resist rolling a moqui marble down desert slickrock or plucking up a river rock to chase scurrying stonefly larva beneath.

Dr. Eric Newell, director of experiential learning at Edith Bowen Laboratory School and summertime river rafting guide, wrote about the secrets stones hold for him: “I like to pick up rounded river rocks, turn them gently in my fingertips, feel the smooth contours, and wonder where they journeyed from to this resting place—how long did it take for the eons to shape and polish them? And what would rivers be without stones?—the meticulous ways the currents stack and sort boulders to sand grains by size, coming to understand that every wave on the surface of the river is created by stones beneath—and the metaphor that provides for seeing and understanding children, adults, and even myself.”

Mountains, boulders, stones, cobbles, gravels, pebbles, sand grains, silt, mud. If the water is muddy or the wind is dusty, we know erosion is happening. It forms valleys, smooths jagged rocks, and carves unexpected slot canyons in the desert. It also causes black blizzards and landslides. According to Mark Milligan of the Utah Geologic Survey, the early decades of the 1900s saw the Civilian Conservation Corps setting to work not only building canals and roads, but contour terracing to stall mountainside erosion here in Utah. There is a sign on Skyline Drive in the Manti-LaSal National Forest that reminds us that those CCC boys were digging horizontal trenches above our cities well into the 1950s.

Many people equate erosion with the destructive forces that wear down earth. Yet, in her book titled “Erosion,” Terry Tempest Williams pairs eroding with evolving. She wrote, “Water freezes and shatters stone; rocks fall from the force of gravity; new rapids appear in rivers. Storms gather and floods roar through dry washes, cutting and scouring a wider channel…” We have water, ice, wind, and time to thank for the erosion that created Natural Bridges and Arches, Coral Pink Sand Dunes and Goblin Valley, and Muddy Creek and Blackburn Draw.

I’m Shannon Rhodes, and I’m wild about erosion’s role in shaping Utah.

Credits:

Images: Courtesy & Copyright © Shannon Rhodes, Photographer
Audio: Courtesy & © Friend Weller, https://upr.org/
Text:     Shannon Rhodes, Edith Bowen Laboratory School, Utah State University https://edithbowen.usu.edu/
Additional Reading Links: Courtesy Shannon Rhodes

Additional Reading:

Atwood, Genevieve. Geology of Utah. https://www.uen.org/utah_history_encyclopedia/g/GEOLOGY.shtml

Manti-LaSal National Forest Visitor Guide. https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5370798.pdf

Milligan, Mark. What Are Those Lines on the Mountain? From Bread Lines to Erosion-Control Lines. Utah Geologic Survey Notes, v. 42 no. 1, January 2010. https://geology.utah.gov/map-pub/survey-notes/glad-you-asked/erosion-control-lines-on-the-mountains/

Olsen, Beth. Utah’s CCCs: The Conservators’ Medium for Young Men, Nature, Economy, and Freedom. Utah Historical Quarterly, Volume 62, Number 3, 1994 by Utah State History. https://issuu.com/utah10/docs/uhq_volume62_1994_number3/s/163708

Oskin, Becky. Mars on Earth: How Utah’s Fantastical Moqui Marbles Formed. 2014. https://www.livescience.com/47936-how-moqui-marbles-form.html


Wenzel, Brendan. A Stone Sat Still. 2019. San Francisco, CA: Chronicle Books. https://www.youtube.com/watch?v=P11LB4A-pjI

Williams, Terry Tempest. Erosion: Essays of Undoing. 2019. New York, NY: Sarah Crichton Books. https://www.amazon.com/Erosion-Undoing-Terry-Tempest-Williams/dp/0374280061

Utah’s Glacial History

Moraine with erratics, Photo Courtesy and Copyright Mark Larese-Casanova, Photographer
Moraine with erratics
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Little Cottonwood Canyon, Photo Courtesy and Copyright Mark Larese-Casanova, PhotographerLittle Cottonwood Canyon
Photo Courtesy & Copyright
Mark Larese-Casanova, Photographer

Hi, this is Mark Larese-Casanova from the Utah Master Naturalist Program at Utah State University Extension.

It is amazing to see just how much of an impact the large amount of snowfall from last winter still has on the annual cycle of nature. Of recent note, wildflower blooms in the mountains seem to be at least 2-3 weeks behind normal schedule. Hiking through snow in late July had me thinking about colder times when Utah’s mountains were covered with ice that flowed as glaciers.

The most recent period of glaciation in Utah occurred between 30,000 and 15,000 years ago when Utah’s climate was, on average, up to 30?F cooler. At times during this period, much of the western half of Utah was covered by Lake Bonneville, which contributed tremendous amounts of moisture as snow throughout Utah’s mountain ranges. As the snow accumulated at high elevations, its sheer weight caused it to recrystallize into ice. Once the masses of ice became heavy enough, gravity pulled them down slope, carving out characteristic U-shaped valleys.

At the top of the valleys, where the glaciers formed, we can often find large, bowl-shaped cirques. In the Wasatch Range, the Little Cottonwood Canyon glacier formed at the top, creating Albion Basin, and reached the mouth of the canyon where calved icebergs into Lake Bonneville. The Uinta Mountains contained such large glaciers that even many of the mountain peaks are rounded.

As temperatures warmed during the end of the last ice age, glaciers receded and left behind large piles of soil and rocks, known as moraines. Terminal moraines at the end of a glacier’s path, can act as natural dams to create lakes. Enormous boulders, known as glacial erratics, can often be found discarded along canyons.

While glaciers don’t currently exist in Utah, there are several permanent snowfields in shaded high mountain areas. So, if you’re feeling a little nostalgic and missing that extra long winter we had this year, you still a chance to hike up above 9,000 feet and cool your toes in the snow.

For Wild About Utah, I’m Mark Larese-Casanova.

Credits:

Images: Courtesy & Copyright Mark Larese-Casanova
Text:     Mark Larese-Casanova, Utah Master Naturalist Program at Utah State University Extension.

Additional Reading:

Utah Geological Survey https://geology.utah.gov/surveynotes/gladasked/gladglaciers.htm

Parry, William T. 2005. A Hiking Guide to the Geology of the Wasatch and Uinta Mountains. University of Utah Press.

Stokes, William Lee. 1986. Geology of Utah. Utah Museum of Natural History.

Red Rock Country

Red Rock Country: Chinese Wall at Bryce Canyon National Park Courtesy NPS.gov https://www.nps.gov/brca/
Chinese Wall at Bryce Canyon National Park
Courtesy NPS.gov
https://www.nps.gov/brca/

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.

Credits:
Photo: Courtesy NPS.gov: https://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. https://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, https://mountain-press.com/item_detail.php?item_key=366

Chronic, Halka. Roadside Geology of Utah. Missoula, MT Mountain Press Publishing Company, 1990 https://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, https://content.lib.utah.edu/cdm4/item_viewer.php?CISOROOT=/upcat&CISOPTR=1328