Tuesday, September 29, 2009

Waterpocket Fold

The Waterpocket Fold is a 100-mile long warp of Earth's crust in southern Utah. Trending SSE to NNW, the Fold extends from the Colorado River valley to the area of Thousand Lake Mountain; most of the scenic terrain created by this geologic formation is now protected within Capitol Reef National Park.

Before the Waterpocket Fold developed, rock layers of this region were stacked horizontally, with older sediments below younger ones. Then, about 70 million years ago, pressure within the North American plate crumpled up the Rocky Mountains; in concert, the rock layers of southern Utah warped downward to the east. Subsequent erosion, augmented by uplift of the Colorado Plateau about 15-20 million years ago, has uncovered the various strata of this tilted layer cake, with older sedimentary rocks (Permian; 270 million years old) exposed on the west edge of the fold and younger deposits (Cretaceous; 80 million years old) on the east. Since some layers are more resistant to erosion than others, the Waterpocket Fold is characterized by an alternating pattern of ridges and basins, interspersed with geologic domes and spires.

The landscape that we observe across our globe today is a product of geology, tectonic activity and erosion; it is but a snapshot in the 4.6 billion-year history of our planet and will continue to change over the coming millenia. Few places on Earth offer a better illustration of these natural, terrain-sculpting processes than does the Waterpocket Fold.