Fantasy Canyon, UT 2008


In October of 2008, I took a group of students to Fantasy Canyon, Utah. Fantasy Canyon is an area composed of unique erosional features located about 40 km south of Vernal, in northeastern Utah. Even though the area is somewhat small (10 acres and it is not really a canyon) it contains some of the most unique geologic features in the world.

Government map of the Vernal, Utah area

With intricate rock formations, eroded by wind and rain over millions of years, the dramatic stone figures stand out from the many other rock formations in Utah’s eastern wilderness.

Fantasy Canyon overlook

The stunning pinnacles, pillars, arches, and knobs that form Fantasy Canyon are formed from the sandstone layer formed from ancient river channel sediment deposits, (pictured below).

Fantasy Canyon Overlook

Pictured above, both the rock above and below the sandstone trapped the sandstone layer resulting in the classic badland topography found in and around the main Canyon.

Fantasy Canyon Oct. of 2008
Fantasy Canyon, Utah

During the Eocene Epoch, 55 to 34 million years ago, the Fantasy Canyon area was at the fringe of a vast subtropical lake – Lake Uinta – that at peak level stretched from the Wasatch Plateau to western Colorado.

Map of the Eocene Epoch of Lake Uinta and Gosuite. (Public Domain image)

Lake Uinta was in a drying phase and retreating westward by the end of the Eocene.

Amazing Geological Formations of Fantasy Canyon, Utah.

Rivers en route to the dwindling lake deposited sand, silt, and clay shed from nearby mountains.

Fantasy Canyon, Utah 2008

Eventually more and more sediment was deposited in lake Uinta, and the once-loose sands, silts and clays were forged into rocks of sandstone, siltstone and shale.

An alien’s head at Fantasy Canyon, Utah

Collectively these rocks are a part of the Uinta Formation that spans extensive areas of the Uinta Basin and nearby Colorado.

Strange Formations of Fantasy Canyon, October of 2008

Differences in the rate of weathering and erosion between dissimilar rock types ultimately shaped Fantasy Canyon.

The mudstone and claystone of Fantasy Canyon, Utah

Pictured above and below, the mudstone and claystone have been stripped away by water and wind, leaving the slightly more durable sandstone to be carved into bizarre, melted wax-like forms.

Wax-like rock formed in Fantasy Canyon

Although the sandstone is more resistant to erosion relative to adjacent rocks, it is in fact extremely fragile.

Fantasy Canyon sandstone in Utah.

The sandstone is fine grained, porous, soft, poorly cemented, brittle, and crumbly.

The bizarre formations of Fantasy Canyon

Because of different rates of weathering, the more durable sandstone remain while the more easily weathered siltstone and shale washed away, yielding this spectacular scenery at Fantasy Canyon.

A coyote looking toward it side in the Fantasy Canyon Formations.

Today’s geologic formations of Fantasy Canyon will eventually give way to weather and then topple and erode into sand, but new formations will appear as the topsoil washes away.

Fantasy Canyon

Because the delicate formations are so fragile the area is referred to as “Nature’s China Shop.”

A rhino looking creature at Fantasy Canyon, Utah

There are inch-wide, black-colored, subvertical, northwest-southeast trending gilsonite dikes that have intruded the rocks at Fantasy Canyon.

Fantasy Canyon 2008, Utah
Intricate Formations at Fantasy Canyon, Utah

Gilsonite, named after U.S. Marshall Samuel H. Gilson, is a type of asphaltite – solidified hydrocarbons. Gilsonite was discovered in the early 1860s.

An impossible reach for a naturally occurring geological formation

The Eocene-aged Uinta Formation is fossiliferous. It contains widely scattered bones, mostly mammals, which roamed the Basin during the Eocene. Fossilized turtle shells are visible in the area.

Another impossible geological reach at Fantasy Canyon, 2008

A similar ancient lake, named Lake Gosiute, existed to the north in the Green River and Washakie Basins of Wyoming.

A filtered view of the geological formations at Fantasy Canyon

Some seams of iron staining do appear but they are very oxidized. The mineral being oxidized could be magnetite or hematite.

Another filtered view of the geological formations at Fantasy Canyon, Utah

The rocks of the Eocene Green River Formation preserve a record of these ancient lakes, including world famous fish and leaf fossils, (pictured below).

Nearby, Maple-leaf fossil found in the Green River Formation. Found in Cowboy Canyon
Leaf fossil found near Fantasy Canyon in the Green River Formation; Found in Cowboy Canyon of the White River
Green River Formation fossils that my students found in Cowboy Canyon October, 2008. (Near Fantasy Canyon and Bonanza)

Additionally, Utah’s much-talked-about oil shale resources, as well as significant conventional oil and gas reserves, are within the strata that accumulated in ancient Lake Uinta.

Palm leaf fossil in the Green River formation near Fantasy Canyon

Within Fantasy Canyon boundaries, you can see 5 different gas-wells in all directions.

My trekking buddy and additional student advisor, (Marc Curtis), taking a picture at Fantasy Canyon, 2008

Because rocks from these ancient lake systems are major oil and gas sources and reservoirs, research conducted here by the University of Utah will help us predict the petroleum development potential of ancient lake deposits in Utah and around the world.

The “White River” in Cowboy Canyon; nearby Bonanza, Utah and Fantasy Canyon. (A good look at the Green River Formation)
In the bottom of Cowboy Canyon near the White River in Utah
My favorite image of the “Two Witches” at Fantasy Canyon, Utah 2008

Fantasy Canyon is one of Utah’s most unique and delicate destinations.

Man-made experiment for the Center of Gravity at Fantasy Canyon on a student field-trip in 2008
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