Grand Tetons National Park

This view is of Mount Moran near Jackson Lake Junction. The Teton Range rises nearly 5,000 to 7,000 feet above the valley (Jackson Hole). The mountain range is a fault-block with a great escarpment on its eastern side where vertical displacement along the Teton normal fault has occurred (Love, 1987). The range core consists of Precambrian metamorphic rocks (gneiss and schist) and granite. Sunlight highlights a vertical diabase dike near the peak of Mount Moran. The age of the crystalline rock in the Teton Range is about 2.5 to 2.8 billion years old, whereas the intrusive dikes are about 1.3 billion years old. The summit is capped by a relatively thin layer of Cambrian Flathead Sandstone. (Love and others, 1973; Love, 1987; Reed and Zartman, 1973, Harris and others, 1997).