ABSTRACT

Early geological work connected with the search for petroleum in Saskatchewan involved consideration of the surface geology. Later it was held that the Pleistocene deposits, which cover most of the southern half of the province, effectively mask the geology of the pre-Pleistocene surface. Most exploration was then based only on the interpretation of geophysical and subsurface data. A better understanding of the Pleistocene deposits and their influence on the landscape makes a reappraisal of this approach necessary. By elimination of the effects of glaciation a picture of the preglacial geology can be obtained. Topographic maps, subsurface structural maps, geophysical maps and air photographs are important tools in this investigation. It involves the evaluation of such features as non-glacial topographic closures and lineamtents, stream adjustments, drainage patterns, and tonal halos. The results of these submask geological studies may prove to be of importance to the petroleum geologist as the preglacial surface in Saskatchewan is essentially a surface of non-inverted relief, i.e. the topography is generally a direct expression of the underlying structure. Some structures are reflected at the surface through thousands of feet of sediments.