Today's Article - The Wave

This article is for quizzes on Tuesday July 7th, 2015...

The Wave is a sandstone rock formation located in the United States of America in Arizona, on the slopes of the Coyote Buttes, in the Paria Canyon-Vermilion Cliffs Wilderness, on the Colorado Plateau. It is famous among hikers and photographers for its colorful, undulating forms, and the rugged, trackless hike required to reach it.

“The Wave” consists of intersecting U-shaped troughs that have been eroded into Navajo Sandstone of Jurassic age. The two major troughs, which comprise this rock formation, are 62 feet (19 m) wide by 118 feet (36 m) long and 7 feet (2 m) wide by 52 feet (16 m) long. Initially, infrequent runoff eroded these troughs along joints within the Navajo Sandstone. After their formation, the drainage basin, which fed rainwater to these troughs, shrank to the point that the runoff became insufficient to contribute to the cutting of these troughs. As a result, the troughs are now almost exclusively eroded by wind, as indicated by the orientation of erosional steps and risers cut into the sandstone along their steep walls. These erosional steps and risers are oriented relative to the predominant direction of the wind as it is now naturally funneled into and through these troughs.

The Wave exposes large-scale, sets of cross-bedded eolian sandstone composed of rhythmic and cyclic alternating grainflow and windripple laminae. The rhythmic and cyclic alternating laminae represent periodic changes in the prevailing winds during the Jurassic as huge sand dunes migrated across a sandy desert. The thin ridges and ribbing seen within The Wave is the result of the differential erosion of rhythmic and cyclic alternating grainflow and windripple laminae within the Navajo Sandstone. These laminae have differing resistance to erosion as they have been differentially cemented according to variations in the grain size of the sand composing them. The soft sandstone, including the ridges and ribbing, of The Wave is fragile. As a result, persons must walk carefully to avoid breaking the small ridges.

In places, The Wave exposes deformed laminae within the Navajo Sandstone. These laminae were deformed prior to the lithification of the sand to form sandstone. Judging from their physical characteristics, this deformation likely represents the trampling and churning of these sands by dinosaurs after their deposition. Dinosaur tracks and the fossil burrows of desert-dwelling arthropods, such as beetles and other insects, have been found within the Navajo Sandstone within the North Coyote Buttes Wilderness Area.