Three eolian (wind-deposited) Jurassic sandstones make a major contribution to the spectacular scenery of the Colorado Plateau. These strata, initially emplaced as dune fields, have compacted into unique sedimentary rocks, cemented by heat and pressure over more than 150 million years.
The oldest of these is the Wingate Sandstone, deposited at the dawn of the Jurassic (about 200 million years ago); in most areas, it sits atop late Triassic redbeds of the Chinle formation. The Wingate forms massive red cliffs with vertical striations, often giving it a curtain-like appearance. Atop the Wingate, the Kayenta formation of horizontal siltstones, conglomerates and sandstone separates it from the second major eolian sandstone of the Jurassic, the Navaho Sandstone. White to pale pink in color, the Navaho has horizontal striations and also forms prominent cliffs; however, it erodes into rounded domes, wavy ledges and curved slickrock formations, many of which are honeycombed and pock-marked by wind-driven sand. The Carmel Formation, a thin layer of shale and limestone, sits atop the Navaho Sandstone, separating it from the Entrada Sandstone, a salmon-colored eolian sandstone that, like the Navaho, erodes into rounded outcrops.
Exposures of the Wingate and Navaho Sandstones are widespread across the Colorado Plateau; both form cliffs in Canyonlands National Park, in the Escalante River Canyon and on the Vermillion Cliffs, north of Kanab, Utah. Wingate Sandstone forms the sheer walls of the Colorado National Monument while Navaho Sandstone forms the spectacular cliffs of Zion Canyon, the domes of Capitol Reef National Park and the towering rock walls along western portions of Lake Powell. Entrada Sandstone also outcrops in Colorado National Monument but is most famous for its many arches and rock formations throughout Arches National Park. Once desolate dune fields, these magnificent sandstones now invite exploration and their images grace calendars and coffee table books across the globe.
