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Table of Contents
Foreword
Preface
Glossary

Chapter 5: Vegetation

5.27: String Fens and Peat Plateaus West of Setting Lake

This area lies within the Lake Agassiz Basin where bedrock is covered by till and glaciolacustrine deposits on which peat has developed ranging from 1 metre to 5 metres in thickness. String fens, with strings transverse to the direction of surface and ground water movement, can be seen at several locations 1. These surround peat plateaus 2, some of which are high enough and dry enough for dark-toned black spruce (Picea mariana) to grow 3. Some plateaus are lighter-toned because forest fires have removed trees 4. The very light-toned areas on the peat plateaus 5 are collapse scars resulting from melting of ground ice. Permafrost exists in the plateaus but not in the strings on the low-lying areas between them. Two of the peat plateaus 6 are good examples of the common teardrop shape with streamlined tails indicating the direction (to the south) of sheet run-off and ground water flow.[i]

Figure 5.27: String Fens and Peat Plateaus West of Setting Lake

Figure 5.27: String Fens and Peat Plateaus West of Setting Lake

Figure 5.27

Vertical air photo: A12942-160

Flight height: 19,000 feet a.s.l.; lens focal length: 153.1 mm

Scale: 1:36,300 (approx.)

Date: September 5, 1950

Location: Township 70; Range 12 WI

Map sheets: 1:250,000 63O Nelson House

1:50,000 63O/3 McNeil Lake

Notes

[i] Interpretation from Mollard, J.D. and Janes, J.R. Air Photo Interpretation and the Canadian Landscape. Ottawa: Energy Mines and Resources Canada, 1984,133.