Geology of the till in a part of Southeastern Manitoba
Muhammad, Mir Jan
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Till is exposed at or near the surface in much of the area between Ste. Anne and Hadashville in southeastern Manitoba. The present study was undertaken to determine the nature of the till, the magnitude of vertical and lateral variation in its grain size, stone lithology and fabric. Mechanical analyses of till samples reveal considerable variation in grain size, with some samples having less than 20% sand while others have more than 70%. Based on sand percentage, the samples in the study area are arbitrarily divided into three textural types: Type A - less than 44 % sand, Type B - 44% to 58% sand, and Type C - more than 58% sand. Till types A and B have an overall similarity in colour, structure and stone lithology. The sand rich type C till can be distinguished by its friable nature and paucity in stones as well as its higher content of crystalline stones. Type A and B tills are exposed between Birds Hill and Brokenhead River and also in the Hadashville area. C type till is exposed over a distance of 6 miles between Brokenhead River and Hadashville. Stone count data show that from Birds Hill on the west to Brokenhead River in the east, the percentage of sedimentary rock types, with some notable exceptions, is high and nearly constant. East of the Brokenhead River the percentage of crystalline rock types increases rapidly, with the higher percentage of crystalline types found in C type till. At any given site there is very little vertical change in stone lithology...