A geological exploration of the Colorado Plateau is an opportunity to observe and understand many of the principles that established the science of geology. For those who have not visited the region previously (or have not had the chance to tour it in depth), this field seminar will provide a comprehensive journey into the geological story of this fascinating landscape. The arc of our trip, from Las Vegas to the Grand Canyon, Bryce Canyon, Zion Canyon and back, provides a remarkably detailed history of the North American continent from the Early Proterozoic to Holocene time. Few places provide the story in such scenic fashion.
As we leave Las Vegas and travel through the Lake Mead and Kingman area we will observe exposures of Paleozoic sedimentary rocks from the Grand Canyon sequence as well as other younger volcanic rocks, and see up close one of the largest engineering feats in history, Hoover Dam. At Diamond Creek (along the only road that reaches the bottom of the Grand Canyon), we will encounter the Proterozoic rocks of the basement complex that underlie much of the Colorado Plateau. The metamorphic rocks are overlain by the Cambrian Tonto Group along the "Great Unconformity". We will spend a day at the South Rim of the Grand Canyon to allow for a comprehensive look at the Paleozoic history by foot, car, or by air (optional).
Leaving Grand Canyon, we will visit the Little Colorado River and a corner of the "Painted Desert" to examine some of the tectonic structures that form the boundary of the Kaibab Plateau. Mesozoic terrestrial sediments dominate this landscape, and at Antelope Canyon we expect to explore a labyrinth that has been carved through the Navajo Sandstone. If the roads are passable, we will investigate exposures along the Cockscomb, a major Laramide monocline traversing Grand Staircase-Escalante National Monument, the spectacular span at Grosvenor Arch, and the odd sedimentary pipes at Kodachrome Basin State Park. We will be traversing outcrops of the late Cretaceous Mesa Verde Group, the source of coal reserves in the Colorado Plateau.
The Claron Formation, exposed in striking fashion at Bryce Canyon National Park, represents a major change of sedimentary deposition on the Colorado Plateau in early Cenozoic time. The freshwater sediments have been eroded into the tall hoodoos along the edge of the Paunsaugunt Plateau. We will then start moving down section into the Jurassic and Triassic sediments exposed in Zion National Park. Zion exposes an early Mesozoic sequence of terrestrial floodplain deposits and coastal dunes that have been eroded in spectacular fashion. Time will be set aside for an exploration of the upper canyon on foot or by tram.
Each participant will receive a field guide that includes a geological and cultural overview of the Colorado Plateau region, and a comprehensive road guide for the route traveled on the trip.