Soils

Biological Soil Crust

NPS

Soils within the monument are made up primarily of eolian (wind blown) material, as well as eroded Entrada, Wingate, and Chinle sandstone bedrock. The texture of the soils range from loamy sands (coarse) to sandy clay loams (fine). Soil eroded from the Entrada and Wingate sandstones, the Chinle shale and Precambrian is shallow, sandy and rocky. Clay soils derived from the Morrison Formation and by pedogenic processes (weathering), are found at higher elevations and are very expansive and slippery when wet.

The desert climate allows only sparse growth of desert shrubs and grasses, thus the importance of fragile biological soil crusts (formerly known as cryptobiotic soils) to provide soil stability as well as a nitrogen source for other plants/organisms to utilize. Soils in the monument are highly permeable allowing moisture to be channeled and trapped between rock layers and along fissures, contributing to lower elevation springs and seeps.