Weathering and weathering residuals on the Canadian Shield

Abstract

A study of the distribution and characteristics of saprolites on the southeast section of the Canadian Shield showed that a close relationship exists between bedrock lithology, that is rocks most easily weatherable, site of the saprolite by respect to local iceflow direction, and its thickness. Since absolute dating methods of saprolites are not yet operational and still need experi­mentation, not very reliable relative dating criteria had to be applied. The overlying till condition, the thickness of saprolite, and the degree of evolution of clay minerals are all open to criticism. Nevertheless, this study suggests that the Quaternary ice has been quite effective in its scouring task, but pro­tected areas exist, showing saprolites 1 to 2 m thick, or even 15 m in the most protected sites.