Geographical Distribution of Post-Glacial Slumping in Southern Alberta

Abstract

Study of more than 100 post-glacial landslides of the slump variety in the plains of southern Alberta reveals that a remarkably high proportion (87%) has occurred on slopes of northerly, northeasterly, easterly, and southeasterly aspect. While lithologic and engineering properties of the Upper Cretaceous sediments and Pleistocene glacial mantle of this area undoubtedly have conditioned the geological behavior of the earth materials affected, it is here contended that microclimatic factors favoring the accumulation and retention of snow on slopes of particular exposure, or aspect, have more strongly controlled the geographical distribution of the observed slumps. Reasons for and consequences of microclimatic control are discussed.