Graded Slopes in Western Kansas

Abstract

Graded erosional slopes of several types occur in western Kansas. As these surfaces are developed on relatively nonresistant and uniform rocks they present particularly favorable conditions for study of their origin. They are described in three groups: (1) graded surfaces of the interfluves, judged to have developed prior to Illinoian time; (2) flanking pediments, controlled by the position of an adjacent stream course, that have developed during late Pleistocene time; and (3) "pedimented tributary" valleys or "concavo-convex" gullies that have developed since mid-Wisconsinan time. It is concluded that although lateral planation by minor streams may have been an important factor in the origin of the first category, the forms classed in the third category were cut by some form of surface sheet action of running water.