Winnipeg 2013
Technical Program

GS6:Quaternary Geology (Poster)
Organizers / Organisateurs: Michelle Trommelen, Roger Paulen
Room / Salle: Exhibits Hall 2FGH
Date: May-22-13
Presenter: Maurice K. Nguyen

Quaternary glaciation and stratigraphy of the Ridge River area, northern Ontario

Nguyen, M.K.,, Hicock, S.R., Western University, Biological & Geological Sciences Building, Room 1026, London, ON  N6A 5B7, and Barnett, P.J., Ontario Geological Survey, 933 Ramsey Lake Rd., Sudbury, ON  P3E 6B5

A comprehensive study of the Quaternary sediments in the Ridge River area in northeastern Ontario provides valuable insight into the glacial past of a region which until now has been studied only in reconnaissance.  An information gap exists in this area which lies near the southern margin of the James Bay Lowland and relatively close to the geographic centre of what was once the Laurentide Ice Sheet.  A stratigraphic study of riverbank exposures not only provides details regarding the behaviour of the Laurentide Ice Sheet in this area but also advances our understanding of the distribution of materials and their related depositional environments in this sparsely studied region.

Conducted during the summer of 2012, fieldwork consisted of helicopter supported exploration of exposed riverbanks in the Ridge River area located approximately 85 km northwest of the town of Hearst, Ontario (with the entire study area covering nearly 6000 km2).  Stratigraphic units at every exposed section examined were carefully measured and described.  Till matrix samples collected were subsequently analyzed for particle size distribution and carbonate content (including calcite and dolomite proportions).  Supplementary data include heavy mineral content, pebble counts (pebble lithology identification), till fabrics and various structural measurements (e.g. orientation of shear planes, extension fractures, striations, etc.) within and below the till units.

The information garnered from field observations and subsequent analyses should reflect the number of distinct till units and their associated ice-flow directions.  Such information should provide a better understanding of local glacial history including ice-flow patterns and past glacial and non-glacial episodes.  Furthermore, the location of the Ridge River study area is of particular importance since it may reveal links between the distribution of Quaternary sediments in the Hudson Bay Lowland and the Canadian Shield to the south.