Clay mineralogy of parent materials derived from uppermost Cretaceous and Tertiary sedimentary rocks in southern Saskatchewan

Soils developed from parent materials derived from uppermost Cretaceous and Tertiary sedimentary rocks have been delineated from those which do not contain any of these younger sediments. The present study was initiated to determine the validity of this delineation. Parent materials from six locations in southwestern Saskatchewan were collected to determine their general chemical and physical properties. Clay fractions from each of these six parent materials were then subjected to detailed chemical and mineralogical analyses. The two parent materials containing the greatest amount of post-Bearpaw bedrock sediments (Jones Creek, Scotsguard) were characterized by substantially more organic carbon and less CaCO3. The presence of coal and the absence of carbonates in local bedrocks were considered to be the source of these deviations. In general, fine clays were comprised of 64–69% smectite, 14–21% illite and 10–13% kaolinite and coarse clay contained 32–39% smectite, 25–34% illite and 11–14% kaolinite. An ex...