Utah Geological Survey

10/15/2026

Have you wondered how geologists determine how old rocks are? Here, the colorful volcanic sandstone and mudstone of the Brian Head Formation in the Dixie National Forest record volcanic activity in SW Utah, which is about 38 million years old. Learn more in this "Glad You Asked" article–http://ow.ly/d3g850zlBml

10/14/2026

Photo of the Week: Erosion has exposed and sculpted Jurassic-age sedimentary rocks in the southern San Rafael Swell. Near Goblin Valley State Park, towering Wild Horse Butte comprises the Morrison and Summerville Formations (top cliff layers), Curtis Formation (middle slope layer), and Entrada Sandstone (bottom reddish layer).
San Rafael Swell, Emery County, Utah
Photographer: Taylor Boden

10/13/2026

10/07/2026

Photo of the Week: Fall foliage adorns the already colorful walls of Jurassic-age Navajo Sandstone in the Zion Narrows. The North Fork of the Virgin River has cut the 1000-foot-deep Narrows in a relatively short span of geologic time (about 1 to 2 million years).
Zion National Park, Washington County, Utah
Photographer: Tyler Knudsen

10/06/2026

Rock Spotlight: Carbonate Nodule from Spor Mountain
This nodule showcases the replacement of carbonate rock with chalcedonic quartz and purple fluorite. The center features sharp, euhedral dark purple fluorite crystals, highlighting the stunning mineralogy of the Spor Mountain mining district.

10/05/2026

Did you know Utah is the only landlocked state in the U.S. with an official state crustacean? The brine shrimp plays a key role in the Great Salt Lake ecosystem and boasts an evolutionary history spanning hundreds of thousands of years in the basin. Learn more in the latest Glad You Asked article: https://ow.ly/Kgws50ZUu1j

10/01/2026

The annual Basin Energy Summit brings together energy partners, policymakers, and the community to collaborate, exchange ideas, and explore new growth opportunities across the Uintah Basin region.

This year’s event featured an inside look at northeastern Utah's subsurface geology, with the UGS displaying 17 borehole cores from the Utah Core Research Center collection.

Thank you to the industry experts and government officials who contributed their insight to this year's presentations and discussions.

09/30/2026

Photo of the Week: Neilson Wash, Wayne County, Utah
Photographer: Diane Menuz

Weathering is evident in this small wash near Factory Butte, composed of sandy shale of the Tununk Member of the Cretaceous-age Mancos Shale. The rounded pockets on the walls of the wash are an example of tafoni, created by weathering through wetting-drying and freezing-thawing cycles.

09/29/2026

Topaz, Utah’s state gem, is a semiprecious gemstone that occurs as very hard, transparent crystals in a variety of colors. Larger crystals and clusters can be found within cavities of white rhyolite. Find topaz and other minerals at Topaz Mountain in Juab County, Utah.

09/28/2026

Did you know extreme heat and pressure can stretch solid rock? Tucked in the northwestern corner of Utah in the Raft River Mountains, a stretched-pebble conglomerate found within the late Precambrian-age Elba Quartzite preserves an epic period of tectonic strain. Tectonic strain is the physical change a rock undergoes in response to tectonic forces. Explore more in this latest GeoSights article: https://ow.ly/hek150ZSgNK