HYDROGEOLOGY OF 2 SASKATCHEWAN TILLS .2. OCCURRENCE OF SULFATE AND IMPLICATIONS FOR SOIL-SALINITY

The occurrence of sulfate salts in groundwater and solids was documented at two sites, named Dalmeny and Warman, where clayey tills overlie regional aquifers. Results showed that the bulk sulfur and sulfate contents of solids could not in general be adequately characterized with point or 'grab' samples from boreholes. At Dalmeny, measurements representing larger averaging volumes revealed a spatially-intricate pattern of sulfate abundance and depletion which extends vertically through the oxidized and unoxidized zones of the till to the underlying aquifer. Similar measurements at Warman suggest that sulfate variability there is limited to the oxidized zone. These findings, and the observed coincidence of sulfate patterns with the groundwater flow patterns documented in Part I, show that the bulk permeability of the till controls the manner in which the subsurface sulfate 'reservoir' is affected by microtopographic focussing of surface water input.