Tag Archive for: geology

By: Peter D. Rowley, Robert F. Biek, Edward G. Sable, Jonathan T. Boswell, Garrett S. Vice, Stanley C. Hatfield, David J. Maxwell, and John J. Anderson

The Brian Head Quadrangle straddles the west edge of the Markagunt Plateau and is roughly centered on Brian Head Peak, at 11,307 feet (3446 m) the highest mountain in southwestern Utah. The peak, encompassing an area of great natural beauty and recreational use, is capped by volcanic rocks that erupted from calderas on the Utah-Nevada border. These volcanic rocks overlie landslide-prone local volcaniclastic strata, which in turn overlie colorful strata of the Claron Formation, centerpiece of Cedar Breaks National Monument in the southwest corner of the map area. The plateau is capped by remnants of the 20-million-year-old Markagunt Megabreccia, Utah’s largest catastrophic gravity slide.

This CD contains geographic information system (GIS) files in ESRI file geodatabase and shapefile formats. Two plates, a geologic map at 1:24,000 scale and an explanation plate, and a 38-page booklet are also included in PDF format. The latest version of Adobe Reader is required to view the PDF files.

GET IT HERE

Uinta Basin, Uintah County, Utah
Photographer: Michael Vanden Berg

The exceedingly rare Graham’s penstemon grows exclusively on the sparsely vegetated outcrops of Green River Formation oil shale deposits and can be found only in the Uinta Basin of Utah and the Piceance Creek Basin in Colorado. Federal protection for this scarce plant could be forthcoming as petroleum development becomes more prevalent in the basin.

stgeorgeutah.com

A swarm, or cluster, of 24 earthquakes have been recorded Tuesday, the first about 37 miles west-northwest of St. George in Nevada, and the others within about a 10-mile radius of the first, see map inset. The earthquakes have ranged from local magnitude 4.1 at both 8:20 a.m. PST and 6:30 p.m. PST, and various lesser amounts throughout the day with the most recent registering local magnitude 3.2 at 6:38 p.m. PST.

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And another great article on Utah quakes and other worldly shakes—
decodedscience.com
Nevada and Utah Earthquakes; Greece, Mid-Atlantic Tremors: January 2014

The world seemed to wake up this week, seismically speaking.

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By: Tyler R. Knudsen and William R. Lund

Historically, the communities of La Verkin, Virgin, Rockville, and Springdale have been affected by a variety of geologic hazards. Recent damaging rock falls, riverine floods, recurrent flash floods and landslides, and problems associated with collapsible soil and expansive soil and rock demonstrate that the communities are vulnerable to geologic hazards, and that public officials require reliable hazard information as they plan for future growth. The Utah Geological Survey has prepared GIS-based information on the kinds and locations of geologic hazards that may affect existing and future development in the State Route 9 Corridor Geologic-Hazard Study Area (SR-9 study area). The SR-9 study area encompasses 97 square miles, and consists of a 2- to 8-mile-wide corridor centered on SR-9, that extends from the eastern part of La Verkin City to the Town of Springdale’s eastern boundary with Zion National Park.

This 13-page report includes nine 1:24,000-scale geologic-hazard maps that cover flooding and debris flows, rock fall, landslides, surface faulting, liquefaction, collapsible soil, expansive soil and rock, gypsiferous soil and rock, soil piping, erosion, and wind-blown sand. Each geologic-hazard map provides information on the data sources and techniques used to create the map, the nature and distribution of the hazard, and possible hazard-reduction measures.

GET IT HERE

Hey geo friends! Check out this dramatic youtube short of a rockfall in Termeno, Italy. It really shows the expanse of destruction a rockfall can cause.

WATCH HERE

MORE INFORMATION on rock-falls and other hazards in Utah

Cliff Lake, western Uinta Mountains, Summit County, Utah
Photographer: Don Clark

Cliff Lake, seen above in midday light, is located adjacent to the larger Wall Lake and near the base of Mount Watson.

Pittsburg Lake, Utah County, Utah
Photographer: Sonja Heuscher

Pittsburg Lake, a glacial tarn formed in a cirque carved into the Cambrian-age Tintic Quartzite in upper American Fork Canyon, Utah County.

upr.org

One of the biggest earthquakes in U.S. history didn’t occur in California. Or Alaska. It happened in the country’s midsection some 200 years ago in an area where today seven states straddle the Mississippi River Valley.

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npr.org

In recent years geologists have hotly debated the age of the Grand Canyon. Some think it’s young (just 6 million years old), while others argue that it dates back 70 million years — to the days of dinosaurs.

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Mirror, mirror…on the Wall Lake! Happy Friday, geo friends!

Mount Watson, western Uinta Mountains, Summit County, Utah
Photographer: Mike Hylland

Wall Lake, a glacial tarn, reflects the morning sun on the Precambrian-age sandstone of Mount Watson (11,521 feet), western Uinta Mountains, Summit County.