Category: Geology
Erosion Made My Favorite Places
https://wildaboututah.org/podcast-player/13227/erosion-made-my-favorite-places.mp3
Bluff of Little Flat Top
Courtesy and Copyright Shannon Rhodes, photographer
Muddy Creek
North Fork Pleasant Creek Terracing
Blackburn Draw
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.
Images: Courtesy & Copyright © Shannon Rhodes, Photographer
Audio: Courtesy & © Friend Weller, https://upr.org/
Additional Reading Links: Courtesy Shannon Rhodes
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
Posted on February 15, 2021 March 18, 2021
Mirabilite Mounds and The Great Salt Lake
https://wildaboututah.org/podcast-player/12415/mirabilite-mounds.mp3
Download file | Play in new window | Duration: 3:36 | Recorded on March 15, 2021
Mirabilite Mounds
in the Great Salt Lake
Courtesy & © Mary Heers, Photographer
Back in October 2019, the ranger at the Great Salt Lake State Park began to notice a white mound forming on the sand flats behind the visitor center. The white mounds turned out to be hydrated sodium sulfate – known as mirabilite- which was being carried to the surface by the upwelling of a fresh water spring. Since the 1940's geologists have known that in this area, 30 inches below the surface, there was a 3 – 6 foot thick shelf of mirabilite. They knew about the fresh water springs What was new was cold air. Since this stretch of sand was no longer underwater, the mirabilite carried to the surface stayed there as crystals, piling up on each other, puddling and spreading out. One mound rose to the height of 3 feet.
Mirabilite Springs in the shadow of the Kennecott Smelter stack
Courtesy & © Mary Heers, Phorographer
When the mounds started to form again this winter, I jumped at the chance to to go and take a look. I must admit at first I was a little underwhelmed at the size, perhaps because the Kennecott Smelter Stack nearby dominates the view, rising to 1,215 feet – roughly the same height as the Empire State Building. But the park ranger got my attention when she told us that mirabilite mounds have only been seen in four places in the entire world – the Canadian Arctic, Antarctica, Central Spain, – and Utah. Just seeing them turns out to be a rare winter treat. When the air warms to 50 degrees, the mirabilite will crumble into a fine white powder and disappear.
Robert Smithson's Spiral Jetty (1970)
My mind flashed back to a trip I'd made to the other end of the lake ten years ago. I'd just graduated from the docent training class at the Utah Museum of Fine Art, and a friend and I wanted to celebrate by having High Tea at the center of the Spiral Jetty, a 1,500 foot, long, 15 foot wide coil of black basalt rock – a stunning example of land art jutting out from the northern shore. We'd been warned that it might be underwater, but when we arrived we were delighted to find we could easily walk to the very center of the spiral as the lake water gently lapped at the edges of our shoes. We clinked our tea cups, and toasted the greatness of the lake.
Suddenly I wanted to see the jetty again, so I hopped in my car and drove to the remote site. I saw the Spiral Jetty was now high and dry. Drifting sand had already started to bury parts of it. The water's edge was now over 300 yards away. I thought of the millions of migratory birds that would be arriving in the spring to rest and feast on the tiny treasures of the lake, the brine shrimp. I hoped a smaller lake would still be enough for all of them.
The recent words of the director of Friends of the Great Salt Lake, Lynn de Freitas, rang in my head: "The Great Salt Lake is a gift that keeps on giving. Just add water."
This is Mary Heers and I'm Wild About Utah.
Photos: Courtesy & Copyright Mary Heers, Photographer
Featured Audio: Courtesy and Copyright Kevin Colver https://wildstore.wildsanctuary.com/collections/special-collections/kevin-colver
Text & Voice: Mary Heers, Generous Contributor, Utah Public Radio
Additional Reading: Lyle Bingham, Webmaster Bridgerland Audubon Society
Mirabilite Spring Mounds Near Great Salt Lake Marina, Utah Geological Survey (UGS), Utah Department of Natural Resources, https://geology.utah.gov/popular/general-geology/great-salt-lake/mirabilite-spring-mounds/
Mirabilite, Mindat.org, Hudson Institute of Mineralogy, https://www.mindat.org/min-2725.html
Tabin, Sara, Rare salt formations return to Great Salt Lake's shores; take a tour while they last, The Salt Lake Tribune, Jan. 13, 2021, https://www.sltrib.com/news/2021/01/14/rare-salt-formations/
USGS 412613112400801 The Great Salt Lake at Spiral Jetty, Site Map for the Nation, U.S. Geological Survey(USGS), U.S. Department of the Interior, https://waterdata.usgs.gov/nwis/nwismap/?site_no=412613112400801&agency_cd=USGS
Case, William, GEOSIGHTS: PINK WATER, WHITE SALT CRYSTALS, BLACK BOULDERS, AND THE RETURN OF SPIRAL JETTY!, Survey Notes, v. 35 no. 1, Utah Geological Survey (UGS), Utah Department of Natural Resources, January 2003, https://geology.utah.gov/map-pub/survey-notes/geosights/spiral-jetty/
Board & Staff, Friends of the Great Salt Lake, https://www.fogsl.org/about/board-staff
Posted on November 23, 2020 April 8, 2021
https://wildaboututah.org/podcast-player/11793/karst-topography.mp3
Download file | Play in new window | Duration: 4:00 | Recorded on November 23, 2020
Entrance to a Karst Cave
Courtesy & © Josh Boling
Rivers run beneath these hills, carving winding caverns through ancient stone, plumbing a subterranean watershed—a second topography, ever changing. What little we've seen must lead further in, places mythology might only describe.
Karst topography' refers to landscapes cleaved apart by the leaching of water through a soluble bedrock layer comprised of carbonate-rich rocks like the limestone and dolomite found throughout Utah's mountains or the evaporate-type gypsum and rock salt layers found in Utah's redrock country. Over time, this erosion by surface and groundwater creates pinnacles, rippling fissures, gaping sinkholes, or springs on the surface—deep caverns, plummeting vertical shafts, and winding tunnels through which entire rivers can flow below.
We floated one such river once, in complete darkness, guided only by a subtle current and the voice of our local guide. He said he was of Mayan descent, so we listened closely when he relayed stories of Chaac, the Mayan god of rain responsible for the generous flow of water through the caverns we explored. Indeed, it is within these same caverns that he dwells, we were told. Further north, in Mexico and the desert southwest, it's Tlaloc, the goggle-eyed Aztecan deity that controls the rain. He, too, is supposed to reside within the body of the earth.
Karst Cave
There's no mythology I'm aware of for my little corner of the globe. So, scientists and explorers alike descend into the karstic caves of northern Utah to see what they might learn. "Utah is unique," one such explorer told me, "with some of the most difficult caves that exist in the world, then some of the most spectacular, and some of the most benign." Intrigued, I set out to see what I could find in my own back yard. Ribs of bleached limestone called karrens spread across a plateau like a washboard road, sinkholes that occupy the better part of an entire meadow, blind valleys sunken into a void in the bedrock, innumerable unnamed springs, and a small, non-descript cavity in the crust—the thing I had really been looking for this whole time.
Main Drain is Utah's deepest and the nation's 11th-deepest cave. It's also wildly difficult and dangerous to navigate, yet absolutely critical to explore for the sake of furthering scientific understanding. I talked to Larry Spangler of the US Geological Survey in Salt Lake City about the significance of karst landscapes like Main Drain. "The caves that are developed in these terrains," Spangler says, "are…valuable sources of information in regard to changes in climate and landscape evolution over time." The chemistries of these caves are unique to their environment, and analysis of mineral deposits within the caves can provide insights into how average surface temperatures have changed over time and how wet or dry the landscape above was in any given period. Karst caves can reveal climate data for specific locales that may help us predict how a warming planet might affect our local ecosystems.
The water that flows through Main Drain and other cave systems like it in the form of snowmelt and subterranean streams carves its way vertically and horizontally through layers of bedrock hundreds of millions of years old—providing researchers a literal inside look at the formation of mountains. And as a map of these subterranean watersheds begins to come together, we gain a better understanding of the hydrology of an area and its effects on water quality.
When I spoke to Spangler, he wanted to make it very clear just how sensitive these karst landscapes are to surface activities, for the health of ecosystems and the integrity of watersheds, of course, but also for the health of human communities. The US Geological Survey estimates that as much as a quarter of the world's population depends on karst landscapes for their water supply. The city of Logan, where my family and I live, sources its water from one of the larger karst springs in the area. The people are drinking straight from the mountain.
Rivers run beneath these hills, and through us as well.
I'm Josh Boling, and I'm Wild About Utah!
Photos: Courtesy & Copyright Josh Boling, Photographer
Sound: Courtesy & Copyright Josh Boling
Text: Josh Boling, Edith Bowen Laboratory School, Utah State University https://edithbowen.usu.edu/
Additional Reading Links: Josh Boling
Sources & Additional Reading
Author's note: Caves and other karst features are inherently dangerous. You should never enter a cave or other karst feature without the appropriate training, gear, and an experienced person(s) to accompany you.
Shurtz, David K & Shurtz, Ryan K, The Discovery, Exploration of, and Sufferings withing Utah's Main Drain Cave, Utah Grottos, April 2005 http://www.jonjasper.com/TonyGrove/MainDrainCave-NSSApril2005.pdf
Haydock, Adam, Cave Dive Operations in Main Drain Cave, Utah, https://www.even-further.com/dive-expedition-in-main-drain-utah
Caving Main Drain Cave, Logan Canyon, Utah, Outdoor Activities, The Dye Clan, August 31, 2013, https://dyeclan.com/outdooractivities/caving/?id=334
Main Drain Cave, Utah Caving, February 14, 2014, https://utahcaving.wordpress.com/2014/02/14/main-drain-cave/
Karst Topography Paper Model (Learning Activity, Grade Level: 9-12), National Park Service, US Department of the Interior, https://www.nps.gov/subjects/caves/karst-topography-model.htm
Karst Topography Paper Model Background
Soto, Limaris R.(modified by), After: Alpha, Tau Rho, Galloway, John P, and Tinsley III, John C., Karst (U.S. Geological Survey Open-file Report 97-536-A), Topography Paper Model, U.S. Department of Interior, U.S. Geological Survey, National Park Service, https://www.nps.gov/subjects/caves/upload/Karst-Topography-Model-_Written-Section_508c.pdf (formerly: https://www.nps.gov/subjects/caves/upload/Final-Karst-Topography-Model-_Written-Section_5-14-2014.pdf)
Weary, David J. and Doctor, Daniel H., Karst in the United States: A Digital Map Compilation and Database, Open-File Report 2014–1156, U.S. Geological Survey(USGS), https://pubs.usgs.gov/of/2014/1156/pdf/of2014-1156.pdf
Lawrence, Lawrence E., Delineation of Recharge Areas for Karst Springs in Logan Canyon, Bear River Range, Northern Utah, U.S. Geological Survey/The Pennsylvania State University, https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.543.5904&rep=rep1&type=pdf
Francis, George Gregory, Stratigraphy and Environmental Analysis of the Swan Peak Formation and Eureka Quartzite, Northern Utah, (1972). All Graduate Theses and Dissertations. 1684 https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=2683&context=etd
Morgan, Susan K., Geologic Tours of Northern Utah, Miscellaneous Publications, 92-1, Utah Geological Survey, Adivision of Utah Department of Natural Resources, (1992), https://ugspub.nr.utah.gov/publications/misc_pubs/mp-92-1.pdf
Connecting Caves, Karst Landscapes and Climate Around the World, Circle of Blue, January 18, 2010, https://www.circleofblue.org/2010/world/connecting-caves-karst-landscapes-and-climate-around-the-world/
Bahr, Kirsten, "Structural and Lithological Influences on the Tony Grove Alpine Karst System, Bear River Range, North Central Utah" (2016). All Graduate Theses and Dissertations. 5015. https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=6053&context=etd