The Geology of the Wasatch Mountains

The geology of the Wasatch Mountains gives the Salt Lake Valley its character. Few places in the world can show off such distinct geologic features in an area as small as the 50 to 70 miles along the Wasatch Front. One section, from City Creek Canyon in the north to Bells Canyon in the south, has 10 distinct geologic zones. Each canyon, some formed by glaciers, others by flowing water, has a different look, with rocks of varying ages and colors.

The reddish rocks visible on a drive up Parley's Canyon come from the Jurassic period. Suicide Rock, at the canyon's mouth, dates from the earlier Triassic age. Lower portions of Big Cottonwood Canyon have billion-year-old Precambrian rock. To the south, Little Cottonwood Canyon has comparatively new formations: a molten igneous mass pushed its way almost to the surface a mere 32 million years ago. Granite formed here was used to build the Church of Jesus Christ of Latter-day Saints Temple in Salt Lake City.

Tongues of the Wasatch Fault run along the front of the Wasatch Mountains. This fault is where the earth cracks as the Great Basin stretches by a couple of centimeters annually. For this to happen, the valleys from California through the Wasatch Range must fall slightly. Portions of Salt Lake Valley's Wasatch Boulevard and 1300 East Street are on fault lines. You can tell that you're near a fault when the east–west streets suddenly get steeper. Although geologists say that a quake could happen any time, the valley hasn't experienced a major one in recorded history. Where to grab some dinner should be a bigger concern than being shaken by an earthquake.