Saprolite occurrences in Quebec are reported and discussed with respect to ice movement. A close relationship was found between ice flow direction, the location, and the thickness of residual saprolites. Where protected against glacial erosion (along fault zones or the southeast sides of hills), the thickness of the deposits exceeds 15 m. The presence of a till cover at most sites provides strong evidence against postglacial formation of the saprolite. Dominance of kaolinite and gibbsite in most of these deposits is indicative of an alteration that took place under warm and humid climatic conditions or which lasted a very long period of time. This suggests that formation of the saprolites occurred during Tertiary time rather than during interglacial stages.