Hoodoo nation

Site: The Queens Garden, Bryce Canyon National Park, Utah

The connection: Bryce Canyon is my favorite geological area on the Colorado Plateau. I have camped nearby so often that a local rancher once called me “the mayor of Kodachrome basin.” I’m interested in the plateau because geological structures and formations here are almost like museum pieces on pedestals -- the full 3-D view of geometry and aesthetics is on display.

Wild forces: The Claron formation was deposited about 50 million years ago in the Eocene era. This area once featured very flat landscapes with meandering rivers that would periodically overflow their banks. The pink and white alternating layers in the Queens Garden reflect deep, ancient profiles created at the expense of fine-grained clay and silt, some interbedded limestone and some conglomerates. The chimney-like projections, or hoodoos, have been etched out by water, wind and changing temperature. They stand tall in many cases because they are capped by a resistant rock layer that has not been completely removed by weathering and erosion. The bedrock is soft and is being attacked from the east by the finger-like ends of tributaries of the Paria drainage system, which flows south and empties into the Colorado River in the Grand Canyon. The Paria sneaked up from the south at a much lower elevation, removed much of the lower strata and then broke through a major fault just east of the garden where it entered the soft stuff.

Standing features: The force of gravity is at work as the sides of the gullies and canyons are steepened by erosion. Hoodoos depend on the presence of nearly vertical fractures that are relatively closely spaced and systematic in orientation. Weathering and erosion simultaneously etch along the fractures and the bedding surfaces. The fractures are highly vulnerable to rapid erosion, leaving what were fracture-bordered parts of the formation standing upright.