ABSTRACT
The adjacent elevated, unsaturated plateaus are drained by vadose conduits. The montane climate of the forested 2700-m-high Kaibab Plateau, north of the eastern Grand Canyon, resulted in the development of a karst surface characterized by numerous steepwalled dolines that appear to represent collapse into dissolving gypsum in the underlying Toroweap Formation. Large closed basins up to several km long, such as DeMotte Park, represent karstification localized along extensional faults. No perennial streams occur on the Kaibab Plateau, attesting to effective karst drainage. Horizontal caves in the Kaibab and Toroweap formations are virtually absent because the primary flow direction for recharge is vertical, through collector structures that feed into extensional fault zones.
