Flaming Gorge

September 02, 2010

SheepRock1b

SheepRock2b
Photographer
: Ray Boren
Summary Author
: Ray Boren

September 2010 Earth Science Picture of the Day Viewer's Choice

When the Uinta Mountains began to rise about 65 million years ago in what is now Utah, the upward faulting broke through a host of other ancient rock formations, several of which are dramatically exposed along Sheep Creek as shown above. Today the drainage is part of Flaming Gorge National Recreation Area and Ashley National Forest on the Utah-Wyoming border. Interpretive signs at pullouts along U.S. 191 and Utah 44 (dubbed a scenic drive “through the ages”) help explain the geologic wonders of a billion years of Earth’s history. The unusual east-west trending Uinta Mountains themselves are composed of Precambrian shale, slate and quartzite up to 24,000 feet (7,315 m) thick and a billion years old. The views into and through Sheep Creek Canyon, which is an arm of Flaming Gorge Reservoir (bottom photo), reveal just a few of the dozen-plus rock strata the Uinta uplift shattered and tilted. These formations date to the Jurassic and Triassic eras. They include the white, petrified sand dunes of Navajo or Glen Canyon sandstone, formed in a vast desert 190 million years ago. The salmon-to-buff Chinle Formation formed some 210 million years ago, and the orange-red Moenkopi Formation, consisting of mudstones from 220 million years ago, helped give the area its name. In recording his crew’s epic 1869 exploration down the Green and Colorado rivers and through the Grand Canyon, John Wesley Powell noted their entry into “a flaring, brilliant red gorge.” He called it “Flaming Gorge.” Photo taken in August 2010.

Photo details: Camera Maker: NIKON CORPORATION; Camera Model: NIKON D60; Focal Length: 18.0mm; Aperture: f/10.0; Exposure Time: Top - 0.010 s (1/100) / Bottom - 0.020 (1/200); ISO equiv: 100; Exposure Bias: none; Metering Mode: Matrix; Exposure: aperture priority (semi-auto); Flash Fired: No; Color Space: sRGB.