Despite the lingering heat, another summer in Utah is coming to a close. The canyons will soon be ablaze with fall colors and the valleys won’t be far behind. In this spirit we have selected another photo from Gerard Dauphinais to give us a little taste of fall. This photo was taken near Fremont Indian State Park, located in west Sevier County. The park is famous for containing many instances of Fremont Indian rock art.

The Sevier Formation contains most of the major rock outcrops seen in the park. A notable feature of the Sevier Formation is the 19-million-year-old Joe Lott Tuff. This tuff (a welded is a welded volcanic-ash) was produced by an explosive volcanic eruption. The massive eruption created the Mount Belknap caldera located about 10 miles south of Clear Creek Canyon. The surface of the originally white, pink, and gray tuff has weathered to darker colors and serves as a “blackboard” for Fremont Indian rock art.

In this picture we see some of the sedimentary rocks that overly the Joe Lott tuff. The rest of the Sevier River Formation consists of sandstones, siltstones, conglomerates,  and additional volcanic ashes, and lava flows that were deposited about 5 to 14 million years ago, when the present topography of the Basin and Range area began forming. The Sevier River Formation was uplifted and tilted around 5 million years ago.

Thanks again for the great photo Gerard! Click through for the full resolution image and click here for more information on Fremont Indian State Park. Remember, you can always submit your photos to us at, on Facebook, or on Twitter.

Notch Peak, House Range, Millard County, Utah
Photographer: Michael Vanden Berg

Abundant trilobite fossils, including  Elrathia kingi shown here, can be found  within the Wheeler Shale east of Notch Peak in the House Range.

Many of the dry desert peaks of western Utah tell a story of shallow tropical seas. As much as 500 million years of deep burial, uplift, and erosion have changed layers of organic mud to cliffs and ledges of layered limestone. Closer inspection reveals abundant fossils, evidence of ancient sea life.

Geologic map of the Johnson Lakes quadrangle, Kane County, Utah, and Coconino County, Arizona,

By: Janice M. Hayden

The Johnson Lakes quadrangle includes parts of the Chocolate (Shinarump) and Vermilion Cliff steps of the Grand Staircase in the southwest part of Grand Staircase-Escalante National Monument. Reddish-brown Lower Jurassic strata of the Vermilion Cliffs dominate the map area. Overall, strata dip gently to the northwest. They are cut by the Paunsaugunt fault at the east edge of the map area, and by several minor, mostly down-to-the-west normal faults. A variety of surficial deposits locally conceal bedrock, including broad alluvial and eolian surfaces deeply incised by modern arroyos. “Picture stone” from the Shinarump Conglomerate Member of the Chinle Formation is quarried locally.

This CD contains geographic information system (GIS) files in ESRI file geodatabase and shapefile formats. Also included are two plates-the geologic map at 1:24,000 and the explanation sheet-both in PDF format. The latest version of Adobe Reader is required to view the PDF files. Specialized GIS software is required to use the GIS files.


Hydrogeochemistry, geothermometry, and structural setting of Thermal Springs in northern Utah and southeastern Idaho,

By:Brennan Young, Katherine, Shervais, Moises Ponce-Zepeda, Sari Rosove, James Evans

This CD contains a 29-page report conducted by undergraduate researchers at Utah State University during 2010 and 2011 under the direction of Dr. James P. Evans. It includes data collected from hot springs in northern Utah and southeastern Idaho, including location, temperature, acidity, salinity, cation concentrations, and maximum reservoir temperature estimates acquired through the application of several cation geothermometers.



The Colorado Plateau is a geological wonderland that encompasses 130,000 square miles (337,000 square kilometers) centered around the Four Corners area of the American West and within the states of Colorado, New Mexico, Arizona and Utah. It ranges in elevation from slightly over 2,000 feet (600 meters) along the Colorado River in the Grand Canyon to over 12,000 feet (3,660 meters) in the Henry and La Sal Mountains of southeastern Utah. More than 90 percent of the plateau lands are drained by the Colorado River and its major tributaries, the Little Colorado, the San Juan and the Green rivers.


Notch Peak National Natural Landmark, House Range, Millard County, Utah
Photographer: Matt Affolter

Cambrian- to Ordovician-aged carbonate rocks (limestone and dolomite) make up Notch Peak, where a 2,200-foot cliff (possibly the tallest carbonate cliff in North America) leads to a deep canyon on the west side of the peak. Pink, Jurassic-aged granite is exposed at the foot of the mountain, and scattered deposits of white, clayey marl deposited in Lake Bonneville during the late Pleistocene are present on the valley floor.

Near Moab, Grand County, Utah
Photographer: Carole McCalla

During Jurassic time, a sauropod walked across mud, sinking deeply into it. The footprints can be seen preserved in the rock near Moab in Grand County. BLM interpretive site.

Long ago, when the Earth had only one continent and one ocean, an earthquake rippled through western North America’s great sand sea. The early Jurassic earthquake left its mark in the vast dunes that now form the famous red cliffs of Zion National Park in Utah, a new study finds.


Kirsten Bahr spent much of her summer enduring near-freezing temperatures, visiting the site of an ancient sea, and squeezing through rock passages that twisted and plunged deep into the earth. All without leaving Cache County.


Torrential rains caused a major mudslide in Alpine just before midnight on Thursday, putting 18 inches of mud into the basement of one home. Kaitlyn Dix was home alone around 11:30 p.m. on Thursday when tragedy was compounded by hardship. She had just gotten a call from her mother, Dixie Dix, saying that her grandmother had died. Within five minutes, the mudslide swept through the yard, breaking through a bathroom window and inundating the basement. Firefighters arrived on the doorstep just as her sister, Nicole, arrived home from a concert, and the women were told they had “30 seconds” to evacuate. They spent the night at a neighbor’s home.


Hanksville-Burpee Quarry, Wayne County, Utah
Photographer: James I. Kirkland

Not a logjam, but a “legjam” of dinosaur bones left in a channel of Jurassic-aged river is being excavated at the Hanksville-Burpee Quarry in Wayne County. BLM interpretive site.