Curved Slopes

Abstract

Explaining curvilinear forms such as these, which are by no means limited to the Navajo, remains a major task. This task is made difficult by the interaction of three broad sets of controls, one set being structural, the second being lithological, and the third being erosional. The difficulty is increased by the variation of the curved forms; these range from domes and smooth “slick rock” slopes, through alcoves, arches, and natural bridges, to horizontal recesses and amphitheatres. Variations in scale also must be considered, as small curved features, especially polygonal tesselation or “elephant hide”, are frequently superimposed on larger curved surfaces.

“Though the Navajo stands first among cliff makers in the plateau province, it does not form platforms or mesa tops ... Its composition, texture, and structure combine to produce smooth or ribbed mounds on which streamways are poorly defined ... (there is) a maze of domes and saucer like depressions”

“ ... the massive, strongly cross-bedded Navajo sandstone cliffs are straight or undercut at the base and rounded at the top, and surfaces between canyons weather into domes, haystacks and tepees”. (Gregory 1938)