A winter storm clears from Superior Peak (11,132 feet) in upper Little Cottonwood Canyon southeast of Salt Lake City. Beneath its thick blanket of snow, Superior Peak is made up of tilted Precambrian-age sedimentary rocks, including the Big Cottonwood Formation and overlying Mineral Fork Tillite.
Ice Age (late Pleistocene) glaciers carved a classic U-shaped valley into granitic rock of the Oligocene-aged Little Cottonwood stock at Little Cottonwood Canyon. Across Salt Lake Valley, the Oquirrh Mountains are home to the Bingham Canyon mine, the largest open-pit copper mine in North America.
Wildflowers on Lone Peak bloom among quartz monzonite (granitic) boulders of the Oligocene-aged Little Cottonwood stock. Near-vertical cliffs on the skyline form part of the glacier-carved cirque near the summit of the 11,253-foot-high peak.
In Christchurch, New Zealand in February, 2011, a magnitude 6.3 earthquake struck six miles from the city center. The sandy type of soil present in the area caused the ground to basically liquefy during shaking.
UGS Geologist Chris DuRoss is interviewed by KCPW: Explore Utah Science to discuss the hazard of liquefaction we face right here in the the Salt Lake Valley.
Little Cottonwood Canyon, Wasatch Range, Salt Lake County
Photographer: Valerie V. Davis
Viewed across Albion Basin from the Secret Lake trail, the southfacing slopes of the Flagstaff Mountain area reveal tilted Cambrian- to Pennsylvanian- age strata. The deformation of these rocks attests to the severe folding, faulting, and tilting undergone by this mountain range.
Geologic Information: The Cottonwood Canyons and many of their tributaries and high-elevation basins were filled with hundreds of feet of glacial ice between 30,000 and 10,000 years ago.
The Little Cottonwood Canyon glacier reached beyond the mouth of the canyon and extended into Lake Bonneville, calving ice bergs into the Ice Age lake. The Big Cottonwood Canyon glacier, however, advanced only about 5 miles down its canyon. Presumably this was due to less snow accumulation in Big Cottonwood’s catchment area.
Valley (alpine) glaciers originate at the head of valleys in high mountain ranges and then flow down preexisting stream valleys. They erode and transport considerable amounts of rock debris, enabling them to significantly modify the landscape. Many distinctive erosional and depositional landforms result; however, this article addresses only the more prominent local features. Beautiful granitic rock that has been sculpted by glacial ice in both canyons enhances the spectacular rugged, mountainous scenery.
Erosional Landforms and Features: Glaciers pluck and abrade a staggering amount of rock from the canyon walls and floors, which is then carried along with the moving ice. Thus, the hefty mass of rock material and ice perform some serious erosion. The valley bottom and walls are scoured vigorously, creating a deeper and much wider U-shaped canyon—one of the most distinctive valley glacial features.
- Utah’s Glacial Geology
- Utah’s Pleistocene Fossils: Keys for Assessing Climate and Environmental Change
- Glad You Asked: Ice Ages – What are they and what causes them?
- Survey News
- Teacher’s Corner: Teaching Kits Available for Loan
- GeoSights: Glacial Landforms in Big and Little Cottonwood Canyons, Salt Lake County, Utah
- Energy News: Uranium – Fuel for the 21st Century?
- New Publications
This CD contains a report (15 pages + 64-page appendices) and three plates (maps at 1:75,000 scale), all in PDF format, that address ground-water quality in Salt Lake Valley’s basin-fill aquifer and provide recommendations for water-resource management and land-use planning. The maps are described in detail in the report and show total-dissolved-solids concentration, ground-water quality classes, and potential contaminant sources.
CD (15 p. + 64 p. appendices, 3 pl.)