Sedona Westerners in the Red Rock News

October 21, 2011

The Sedona Westerners “get” Grand Canyon Geology

 


by Karen Schudson

On September 14, 2011, a small group of the Sedona Westerners Hiking Club had the pleasure of joining Sedona geologist Paul Lindberg as he shared his knowledge of the rock formations and layers of the Grand Canyon. Paul is known and respected for his many years of research and “mapping” of the geology of northern Arizona. He is long-time member of the Sedona Westerners, and in his “retirement” is generous to us with his time and expertise. He still covers more ground on foot than most of us, mapping and watching, for example, the developments at the several sinkholes in the Sedona area, among other interests.

Braving a day of intermittent rain, the “Trackers” group met at Posse Grounds and carpooled to the Cameron Trading Post. From here, Paul explained, the Little Colorado River gorge proceeds west into the Kaibab Uplift. After viewing the shallow canyon formations that eventually lead to the Grand Canyon, the group toured the Trading Post and surrounding buildings. Paul pointed out that many tourists often miss the superb craftsmanship of early Arizona architects who preserved treasures of prehistoric rocks by incorporating real fossils, dinosaur tracks, pictographs and petroglyphs into the stones of their buildings.


The Trackers group of the Sedona Westerners gathers with geologist Paul Lindberg at Lipan Point on the South Rim of the Grand Canyon. Lindberg explained for the group his model of the basalt and granite and sediment layering that forms the the rock layers. The clouds and threatening rain provides drama and keeps the group alert.

After leaving Cameron, the Trackers drove along the Little Colorado River canyon’s south rim. A few miles west on Highway 64, they encountered a prime example of Kaibab monocline. A monocline is a step-like fold in rock strata formed when overlying younger sediments are draped over ancient faults. Paul explained that Kaibab limestone formed 252 million years ago. When viewed from the South Rim of the Grand Canyon, this layer of cream to grayish-white rock resembles a bathtub ring around the entire Grand Canyon.

At the next stop, the Little Colorado River gorge viewing area, one could clearly see the unusual monocline features of the Kaibab limestone. Fossilized brachiopods, coral, mollusks, sea lilies, worms and fish teeth can be found within this marine stone. The Kaibab Sea was the last ocean to cover Arizona and much of the southwest.

Continuing west, the Trackers encountered an ever- deepening Little Colorado gorge and a climb to higher elevation where a beautiful piñon-juniper forest emerged. Here, the Westerners officially entered the Grand Canyon National Park. President Theodore Roosevelt, a major proponent of Grand Canyon preservation, visited it frequently to hunt and enjoy the scenery.

Paul pointed out that Cedar Mesa, a remnant of the Mesozoic strata that once covered the entire area, lies to the east. The Mesozoic Era refers to a geologic period from about 65 to 250 million years ago, when dinosaurs roamed the world. Many geologists suggest that this era ushered in modern animal life.

Moving on to Lipan Point, the Westerners experienced one of the Grand Canyon’s most breath-taking vistas. The skies cleared as Paul set up his interactive geologic model, demonstrating how each Canyon rock layer developed. The last stop brought the group to Shoshone Point, a lesser-known area within the national park. Hiking an easy mile, the Trackers gazed once more upon the Canyon’s fascinating jumble of rock formations.

The Grand Canyon is neither the deepest nor widest canyon in the world, but its overwhelming size, intricate colors and beautifully preserved and exposed ancient rock layers are breath-taking. With Paul’s geological explanations and rain rolling in and out all day, the Westerners enjoyed new knowledge, colors, sun and shadows of the dancing storms.

The Westerners always welcome new members. If you are interested in joining the club, log onto our website, www.sedonawesterners.org., for membership information. You may also join at one of our monthly meetings. Our next one will be on Thursday, Nov. 10, beginning at 7p.m. at the Jewish Community of Sedona and the Verde Valley Center, 100 Meadowlark Drive, Sedona.