Glad You Asked: Needing a Great Resource for Teaching Your Students About Utah Fossils?


Needing A Great Resource for Teaching Your Students About Utah Fossils?

by Marshall Robinson

The UGS has many resources and tools for teachers including teaching kits, geologic guides, geology-related videos, and maps. Additionally, our interactive web maps are a great resource to start with as they provide a wide variety of geologic information in one spot that teachers from across the world can access. Over the past several years, the UGS has created these user-friendly, informationrich interactive maps to enable map users to explore and understand geology in a more immersive way.

Screenshot of the Geologic Map Portal showing an oblique view of Mt. Timpanogos and Provo Canyon from the south. The 3-dimensional base map allows the user to see the relationship between the landscape and geologic formations (colored polygons), faults (heavy black lines), and ancient shorelines of Lake Bonneville (blue lines).

The Geologic Map Portal was the first interactive map created for the UGS website, and it displays a collection of over 800 of Utah’s best geologic maps. Every geologic map is available for download in various formats, with some of the more recent maps (and all 30′ x 60′ quadrangles) available in a GIS (geographic information system) format. Each colored polygon (which represents a closely related group of rocks, i.e., formations) is clickable, which opens a pop-up showing detailed rock unit descriptions. An improvement to this application came a couple years ago when the 2-dimensional base map was converted to a more true-to-life 3-dimensional base map. This improvement allows the user to tilt and rotate the map to see the rock units in a way that helps them better understand the relationship between geology and landscape. Elementary school teachers and college professors alike can take advantage of this new visual aid to help them teach their students geology in both the classroom and field. Although experiencing geology in person and in the field is probably the best way to understand difficult geologic concepts, our interactive map can certainly add to the experience as it allows you to see the geology of any given location in Utah whenever you want.

In the past 10 years, the UGS has built over 20 interactive maps focused on many aspects of geology. Some of the more useful applications for teachers are centered around popular geology, geologic hazards, and energy and mineral resources. Every interactive map we have created is on the UGS Interactive Maps web page, but a brief summary of some of our more helpful interactive maps follows.

Screenshot of the GeoSights interactive map. Here, people can find many of Utah’s very unique geologic wonders.

Popular Geology

(click on “Popular Geology” filter on Interactive Maps web page):

This option is for those looking for more “general information” interactive maps. These maps give detailed information about rockhounding, fossil sites, pretty landscaping rocks, and fascinating geologic sites throughout the state (called GeoSights). These interactive maps are a great resource for finding and understanding some of Utah’s more fun geologic resources.

Screenshot of the Utah Quaternary Fault & Fold Database interactive map. The different line colors correspond to how recently the fault last moved and ruptured the ground surface, generating a large earthquake.

Geologic Hazards

(click on “Hazards” filter on Interactive Maps web page):

The Utah Quaternary Fault & Fold Database map shows all of Utah’s active faults. On this interactive map one can find if their home or prospective home is near a fault line. The lines on this map represent faults generally considered to be likely sources of large earthquakes (about magnitude 6.5 or greater). Additionally, a more all-inclusive hazards application is being developed that will display all available geologic hazard data in one interactive map.

Though it is not a true interactive map, we also provide an interactive “story map” of Large Earthquakes on the Wasatch Fault. This teaching tool is great for anyone looking to gain a general understanding of Utah’s most hazardous fault system as you can scroll through and learn when large earthquakes have occurred on the Wasatch fault over time in addition to how we have gathered this information.

Energy Resources

(click on “Energy Resources” filter on Interactive Maps web page):

Many teachers may not know that the UGS houses rock core samples and cuttings from thousands of oil and gas wells in a large warehouse building known as the Utah Core Research Center. We created an interactive map to display all of the data from each well in a user-friendly format. These data include information about well location and depth, rock type, and, in some cases, high-resolution photos of the core. Another useful resource map is about Utah’s mining and industrial resources. This new interactive map shows where all of Utah’s mining districts are located as well as where limestone, gypsum, dolomite, and bentonite resource potential is best in Utah. Seeing the location of these mineral resources is an important step in learning the geologic history of Utah because specific minerals are found in specific geologic environments (for more information on this topic, see the “Glad You Asked/Teacher’s Corner” article in the September 2018 issue of Survey Notes).

The UGS website has interactive maps for a broad audience. Everyone from amateur rock-hounders to teachers to researchers and consultants will find valuable data in our interactive maps. Other UGS interactive maps cover topics ranging from geothermal and wetlands data to groundwater and mineral resources. We continue to work hard on providing the most up-to-date and accurate data in the most user-friendly way possible.

Satellite image of the evaporation ponds at Intrepid Potash Inc.’s mining operation near Moab. Image from Google Earth © 2018 Google.

Glad You Asked: What Are Those Blue Ponds Near Moab?


Glad You Asked: What Are Those Blue Ponds Near Moab?

By Stephanie Carney

If you have ever visited Dead Horse Point State Park, you may have noticed bright blue ponds glistening off to the east. These are not a mirage but are solar evaporation ponds used in the process of mining potash. The mine is currently owned and operated by Intrepid Potash Inc., and the ponds cover about 400 acres of land 20 miles southwest of Moab.

Sylvite from Intrepid's potash mine, Moab, Utah.

Sylvite from Intrepid’s potash mine, Moab, Utah.

Potash, a water-soluble potassium salt, is solution mined from the Paradox Formation more than 3,000 feet below the ground. Water from the Colorado River is injected down through a well into the potash-bearing strata, where it dissolves the salts. The resulting brine is extracted from a different well and pumped into the evaporation ponds. Blue dye is added to the water to enhance evaporation. The dye increases the absorption of sunlight and therefore increases the rate of evaporation. As evaporation progresses, the ponds become shallower and turn shades of light blue while the potash precipitates out of solution and is deposited on the bottom of the pond. The ponds turn a tannish brown color when nearly all the water has evaporated and the potash is ready to be harvested.

Satellite image of the evaporation ponds at Intrepid Potash Inc.’s mining operation near Moab. Image from Google Earth © 2018 Google.

Satellite image of the evaporation ponds at Intrepid Potash Inc.’s mining operation near Moab. Image from Google Earth © 2018 Google.

“Potash” is a general term that refers to a variety of potassium salts, such as potassium chloride (KCl), that are mainly used in fertilizer products, but also in the production of soap, glass, ceramics, and batteries. Historically, the term refers to potassium carbonate (KCO3), which is obtained by combining ash from burned plant material (usually hardwood trees) with water in large iron pots. Through evaporating and leaching of the “pot ash,” a residue of potassium carbonate is left behind that historically was used in the process of making soap or glass and ceramic products as early as A.D. 500. In North America in the 17th and 18th centuries, potash became an important industrial chemical and agricultural commodity. Large asheries were built to process the timber cleared and burned by settlers as they expanded westward across the U.S. By the mid-19th century, however, asheries became obsolete after a large deposit of natural potash was discovered in Germany and the birth of potash mining began. Natural potash deposits occur all over the world, but the largest reserves are in Canada. Other significant deposits are in Russia, Belarus, China, Israel, Jordan, and the U.S.

Schematic diagram of solution mining at Intrepid Potash Inc.’s Moab operation.

Schematic diagram of solution mining at Intrepid Potash Inc.’s Moab operation.

The potash mined near Moab is from the Pennsylvanian-age Paradox Formation, which was deposited between 315 and 310 million years ago in the Paradox Basin. During the Pennsylvanian period, the basin was an embayment to a large ocean and experienced cycles of open-marine conditions with freely circulating ocean water and restricted-marine conditions where access to the open ocean was blocked. During open-marine conditions, layers of shale, siltstone, limestone, and dolomite were deposited. When the basin was closed, the hot and dry climate during this time led to high rates of evaporation, and layers of salt were deposited. The salt is mostly halite (NaCl), but layers of sylvite (KCl) and carnallite (KMgCl3.6H2O) were also deposited.

Geologists have identified at least 29 cycles in the Paradox Formation, each represented by a specific sequence of sedimentary and evaporite rock layers, though only 18 cycles are known to contain potash minerals and only a few of those may have economically viable deposits. Individual salt deposits can be up to 1,000 feet thick in some places in the basin. Under the pressure of overlying strata, salt becomes ductile and because it is less dense than other rocks, it moves upward creating folds and diapirs. The Cane Creek anticline, in which the Intrepid potash mine is located, is a large, broad fold created by salt moving upward and bowing the rock layers above it. The potash mined by Intrepid is from Paradox Formation salt cycles number 5 and 9, which occur near the top of the formation. The salt is about 200 feet thick in cycle 5 and about 150 feet thick in cycle 9. The mined potash zone within each cycle, however, is much thinner, typically less than 10 feet thick.

Paleogeographic map of Utah during the Pennsylvanian period, approximately 308 million years ago, showing the Paradox Basin as an embayment to a western ocean (map modified from Ancient Landscapes of the Colorado Plateau by Ron Blakey and Wayne Ranney).

Though the cyclic deposits of the Paradox Formation were discovered in the 1920s, it was not until the mid-1950s during exploration for oil and natural gas that a potential economic potash resource was discovered within the Cane Creek anticline. By the early 1960s, the Texas Gulf Sulfur Company had built an underground mine and began room-and-pillar mining the potash from cycle number 5. Before operations began in 1964, however, an explosion of methane gas trapped 23 men, 18 of which were killed, during construction of the mine.

Because of hazardous gas pockets, high mine temperatures, and the thin, contorted, and difficult-to-mine potash layer, the operation was converted to solution mining in 1970.

The U.S. Geological Survey estimates that the Paradox Basin contains around 2 billion tons of potash resource, though depth to the resource (more than 5,000 feet in some areas) and complex geology have made exploration for economic deposits challenging. The current market price for potassium chloride, the most commonly produced form of potash, is about $200 per short ton, but price has been quite variable in the last decade. Intrepid’s capacity is about 100,000 short tons per year of potassium chloride, from their Moab operation, which is the only potash mine in the basin. Intrepid’s Moab operation along with two other operations in other parts of Utah (see Survey Notes, v. 44, no. 3, p. 1-3) produced 444,000 short tons of potash in 2017 (which includes both potassium chloride and potassium sulfate), the value of which was approximately $210 million. Utah and New Mexico are the only two states that currently produce potash. Because potassium is an essential nutrient for life and there is no substitute, potash mining in Utah likely has a bright and long future.

Glad You Asked: What Are Ice Caves?

Glad You Asked: What Are Ice Caves?

By Jim Davis

Ice caves are caves in bedrock that host year-round ice. They differ from caves formed within ice, which are designated glacial caves. Ice caves are exceptional because they are not only scarce, but they are located far outside zones of permafrost—at low elevations (near sea level) and low latitudes (between around 30° and 70°), where they maintain a much lower average annual temperature than that of the air above. How cold temperatures persist in these spaces is a matter of cave geometry; the physical properties of air, water, and rock; the weather; and time. In Utah, ice caves are well developed in limestone caves and sinks in the Bear River Range, Uinta Mountains, and other areas such as talus slopes and lava flows.

American explorer Edwin Swift Balch (1856–1927) attributed much of the cause of ice caves to The Winter’s Cold Theory, the idea that the cold of the winter perpetuates through the summer. Balch took the presence of ice at the entrance of caves as evidence for the theory, noting that cold winter air is a requirement for ice cave formation and that ice had never been found beyond 200 meters (650 feet) from the entrance of a cave or deeper than 150 meters (490 feet). Therefore, the presence of year-round ice was due to capture and retention of cold from the previous winter rather than any natural processes operating in the cave.

Ice caves are differentiated into two types by air flow and cave structure: static ice caves and dynamic ice caves. Static ice caves flood with cold air in winter and have little air circulation in the summer, with the chilly, dense air settling in and remaining stable. Entrances in these caves are higher than the downward-sloping body of the cave and are referred to as “cold sock,” “cold pocket,” or “cold trap” caves. Conversely, dynamic ice caves have low entrances, an upward-sloping body, and conduits to the surface at the top of the cave. Dynamic ice caves are cooled by the “chimney effect,” where cold air is sucked up the entrance in winter as warm air exits the above conduits. Air flow is reversed in summer as cold air drains downslope out the entrance and warm air is drawn in through the higher conduits. The result is a continuous annual draft of cold air at the lower section of the cave. Dynamic air circulation also produces freezing talus slopes, which can be thousands of feet below areas of permanent ice.

Ice formation requires a source of water. Fractures and fissures in the bedrock allow water to seep in and freeze, or precipitation or runoff enter directly into the cave or sink. Masses of ice and snow in the cave from previous winters thwart rising temperatures in summer, as available heat energy is sunk into melting or sublimating the ice (latent heat) and warming water (specific heat) rather than warming the cave air. Once a cave builds up a sizable mass of ice and a large volume of the surrounding bedrock becomes cold, thermal inertia propels frigid temperatures through the heat of summer.

Duck Creek Ice Cave, formed in a sinkhole on the Markagunt Plateau, is an example of a cold trap ice cave. Duck Creek is small and, although always cool, does not quite meet the strict definition of an ice cave, often melting out in late summer. Similarly, the namesake of Ice Cave Peak in the Uinta Mountains, previously containing multiyear ice, has reportedly melted out. A classic disappearing stream, Big Brush Creek Cave, estimated at nearly 5 miles in length, is not just a cold air sink but a water sink consuming Big Brush Creek into its lengthy passageways. The Vernal Express wrote in 1893 “. . . it is called the Ice Cave because all summer long the entrance, to a depth of several hundred yards, is half filled with glittering ice . . .” During years of torrential spring runoff, the heat from floodwaters melts all the ice in the cave. An immense bluish ice column just inside the entrance has endured through multiple years in historical times, reported in August 1899 in the Salt Lake Herald as being “eight feet in diameter and reaches from the ceiling to the floor” and “would perhaps remain forever were it not for the rush of an occasional flood, which sweeps it away and into the depths below.”

Ice has been reported beneath talus slopes in the Wasatch Range and Wasatch Plateau, and in the blocky lava flows of the Black Rock Desert. An extraordinary example is in the Ice Springs lava flow “cave” in Millard County where the annual mean air temperature is around 52°F, but the surface temperature of the dark basalt can exceed 140°F in summer. In his 1890 monograph, Grove Karl Gilbert labeled this the “Natural Ice House” and observed ice there in late September. Gilbert hypothesized the ice was a result of (1) accumulation of cold water from melting snow, (2) protection from the sun by “a heavy cover conducting heat poorly,” (3) shelter from wind, and (4) evaporation. Much of the causes of the Ice Springs ice cave can be attributed to the “Balch effect,” where flattish areas with coarse, blocky materials can have ground temperatures that are more than 10°F cooler than the surrounding mineral soils. Winter air descends into the spaces between the blocks, displacing lighter, warm air. In the summer the cold air remains in the spaces between the rocks. The Ice Springs cave has been without ice at times, however, as reported by the Millard County Chronicle on September 10, 1942, as dry and bare as “Mother Hubbard’s Cupboard,” with the Chronicle later reporting 36-inch-long icicles on April 22, 1948.

Akin to ice in blocky fields, humans have reproduced the conditions to make ice in places where the thermometer never dips below freezing. Allahabad, India, has no frost days, but ice was created in winter under the favorable weather of a clear night (for radiative cooling) and a dry, light northwest wind (to utilize the latent heat of evaporation). With these conditions met, small, porous earthen jars were placed on a thick bed of loose, dry rice straw for insulation in a 2-foot-deep hollow dug in the soil. The jars were filled with water, placed 6 inches below ground, and covered with mats. In the morning, thin films of ice were collected from the jars and stored in an ice house. An ice crop could be harvested when overnight temperatures dipped below 52°F. The Indian ice industry thrived in the early 19th century until supplanted by the cheaper, higher-quality New England ice, or “crystal blocks of Yankee coldness,” cut from the coastal ponds of Massachusetts and shipped to tropical ports around the world.

Humans have also unintentionally recreated ice caves as tunnels, mines, shafts, and wells. The Salt Lake Mining Review wrote in 1916 of an ice tunnel near the divide between Little Cottonwood and American Fork canyons known as the “North Pole.” In winter and in summer, the old mine tunnel had a “solid wall of ice.”

Survey Notes, v. 51 no. 1, January 2019

“Glad You Asked” January 22, 2015

This soil might just look like some crusty dirt. However it’s the crust on the dirt that makes this soil so very important. Tread lightly through this “Glad you Asked” article on soil crusts to find out more!


“Glad You Asked” January 15, 2015

Have you ever been on an outdoor adventure when you found yourself faced with some kind of geological feature, only you weren’t sure which one? ..It looks like Paul Bunyan’s Woodpile, but is this it?..

Check out our “Glad You Asked” article where you can learn more about how Geographic Names came to be officially recognized, and explore the online database of where these places are located!


“Popular Geology” December 18, 2014

While the weather has been warm, and there’s not a lot of snow or ice around, it’s a great time of year to look at the Ice Age animals of Utah. Did you know that Great Salt Lake is the remnant of Ice Age lake, Lake Bonneville? Read more about this different age in Utah in our “Popular Geology” subjects HERE.

“Glad You Asked” November 20, 2014

Trilobites are always a fun find when you’re exploring the outdoors, but how much do you know about Trilobites as living organisms? Maybe you’re just interested in finding your own Trilobite fossils. Read more about the little critters in our “Glad You Asked” article HERE!

Glad You Asked: October 23, 2014

Cooler weather is on its way, so we’ve got a cool “Glad You Asked” article to compliment the changing seasons! It’s a beautiful time of the year to get out into Utah’s geology. Maybe some of you have noticed these groovy rocks out on your outdoor adventures. What are those grooves in the rocks, and how did they get that way?

Read more about Glacial Striations and Slickensides HERE!

Glad You Asked: October 9, 2014

We’ve got some Great Salt Lake trivia for you to end the day on—how many think you can answer correctly?? Check out our “Glad You Asked” article below for the answers.

1. What do Great Salt Lake, the Bahamas, the old Hansen Planetarium in downtown Salt Lake City, the Manti LDS Temple, and Hearst Castle in San Simeon, California, have in common?

2. What does the original Saltair resort on the south shore of Great Salt Lake have in common with the coasts of Indonesia, Thailand, and northwestern Malaysia?

3. What two things do Great Salt Lake, Apollo 16, and northern shovelers and common goldeneyes (ducks) have in common?

Find the answers HERE

photo by Stevie Emerson

Glad You Asked: September 18, 2014

When I was a child, my family would often go camping in the summers. I would pick up various rocks and ask my dad what they were. “They’re called Leavarite, so you leave em’ right there.” While this is no “Leavarite,” it is something a lightning strike left behind. Most people have never seen it, and those who have may have never realized what it was at the time. This remnant is called a Fulgurite. Fulgurites are natural tubes or crusts of glass formed by the fusion of silica (quartz) sand or rock from a lightning strike. Their shape mimics the path of the lightning bolt as it disperses into the ground.

Read more about fulgurites in our Glad You Asked article HERE!