Dugway Geode, Utah

Title:
Dugway Geode, Utah

Description:
"Approximately 6 to 8 million years ago (Miocene epoch), volcanic activity occurred in western Utah and deposited an extrusive igneous rock called rhyolite. Trapped gasses formed cavities within the rhyolite, and millions of years of ground-water circulation allowed minerals to precipitate into the cavities. The result is geodes with spherical shapes and crystal-lined cavities. Roughly 32,000 to 14,000 thousand years ago, a large body of water known as Lake Bonneville covered most of western Utah. The lake's wave activity eroded the geode-bearing rhyolite and redeposited the geodes several miles away in the Dugway geode bed area as lake sediments. Most geodes are typically hollow whereas others are completely filled with massive, banded quartz. The most common mineral found within the geodes is quartz in various colors: clear (rock crystal), purple (amethyst), and pink (rose). From Salt Lake City take I-80 westbound until you reach the Tooele turnoff (exit 99). Travel south on Highway 36 for about 40.5 miles to the Pony Express Road (which is the dirt road just past Faust). Turn west (right) and proceed 50.1 miles on the Pony Express Road to the Dugway geode bed turnoff (sign may be missing). Turn north (right), proceed up the dirt road and look for recent diggings." http://geology.utah.gov/utahgeo/rockmineral/collecting/rkhd0500.htm

Author:
UTAHnmaz

Tags:
Dugway, Geode, Utah,