The Wave is a geological marvel located within the Coyote Buttes North section of the Paria Canyon-Vermilion Cliffs Wilderness, straddling the border region of Utah and Arizona. Its distinctive, undulating geometry and vibrant bands of color resemble a frozen, cresting ocean swell. This appearance is the result of complex processes involving ancient geology, mineral chemistry, and relentless erosion. The location is highly protected due to its fragile nature.
The Specific Rock Type
The material composing The Wave is a type of sedimentary rock known as sandstone. Geologically, it belongs to the Navajo Sandstone formation, which is extensive across the Colorado Plateau. This rock unit was deposited approximately 190 million years ago during the Early Jurassic period. The Navajo Sandstone is primarily composed of well-sorted, rounded grains of quartz, held together by a mineral cement. The purity of the quartz grains means the rock would naturally be white or light pink if not for later mineral infiltration.
Structural Formation of the Wavy Patterns
The characteristic wavy appearance of the rock is directly related to its origin as wind-blown sand dunes. During the Jurassic period, this area was part of an enormous ancient sand sea, or erg. This internal structure was preserved when the sand became rock, resulting in layering called eolian cross-bedding. This cross-bedding represents the fossilized slip faces of migrating dunes, intersecting at various angles that reflect ancient wind patterns.
Over millions of years, differential erosion began to sculpt the rock along these internal planes. The different layers of the cross-bedding have varying resistance to weathering due to differences in grain size and cementing material. Erosion initially began when water runoff incised troughs along existing joints. However, the ongoing erosion is primarily driven by wind and abrasive sand grains funneled through these troughs. This constant abrasion selectively removes the softer material, creating the flowing, wave-like surfaces seen today.
The Role of Coloration and Weathering
The striking colors of The Wave, which range from reds, oranges, pinks, yellows, and white, result from chemical processes acting on the rock’s mineral content. The coloration is primarily caused by iron oxides, with hematite being the main source of the deep reds and oranges. These iron minerals were originally deposited as coatings on the quartz grains.
The vivid bands of color developed long after the sand dunes had lithified, through a process known as diagenetic coloration. Groundwater, carrying dissolved iron compounds, migrated through the porous sandstone, alternately dissolving and reprecipitating the iron oxides within the pore spaces. This movement created complex, swirling patterns of coloration that often follow the lines of the original cross-bedding.
The final smooth, polished texture of the rock surface is a result of modern weathering by wind and water. Aeolian erosion, where wind carries fine sand that acts like sandpaper, continuously scours and polishes the exposed surfaces of the Navajo Sandstone. This abrasive action enhances the visibility of the internal cross-bedding and the iron oxide bands, contributing to the formation’s flowing appearance.