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Table of Contents
Foreword
Preface
Glossary

Chapter 3: Geologic Structure and Landforms

3.70: Lake Agassiz Strandlines Along the Northeastern Edge of Riding Mountain National Park

On this photo Riding Mountain National Park (RMNP) is in the southwest, its boundary 1 marked by cutlines through the forest. At least five strandline zones 2, 3, 4, 5, 6 can be identified, the highest and oldest being in the southwest 2. As Lake Agassiz retreated to the northeast, it left behind strandlines whose prominence depends on how long the lake stood at a particular level; large prominent ridges indicate a long period of still stand. In the highest zone 2 are several individual lines 7, and below the lowest zone 6, tonal variations in cleared fields 8 indicate very low ridges which may have originated as offshore bars.

Within the park all the land is covered by coniferous/deciduous woodland, the darker toned patches 9 indicating stands of coniferous trees. Outside the park some land has been cleared for agriculture. In the fields the strandlines show up as light-toned areas 10 where dark-coloured soil particles have been removed by rain splash and wind erosion. The Ochre River 11 drains from the central part of RMNP to Dauphin Lake (off the photo to the northeast). It meanders and has deposited shale eroded from the highlands on the insides of bends resulting in light-toned areas 12. A straight drainage channel 13 has been excavated parallel to the general trend of the strandlines.

The boundary between townships 22 and 23 runs across the area. It is the sixth correction line in the DLS system, corrections being about three quarters of a mile (1.2 km) 14. Section lines 15 and quarter-section lines 16 can be seen. Several farms can be identified 17, but there are no nucleated settlements in the area.

Figure 3.70: Lake Agassiz Strandlines Along the Northeastern Edge of Riding Mountain National Park

Figure 3.70: Lake Agassiz Strandlines Along the Northeastern Edge of Riding Mountain National Park

Figure 3.70

Vertical air photograph: A15229-23

Flight height: 20,000 feet a.s.l.; lens focal length: 152.26 mm

Date: June 4, 1956

Scale: 1:37,300 (approx.)

Location: Townships 22 and 23; Ranges 17 and 18 WI

Map sheets: 1:250,000 62J Neepawa

1:50,000 62J/13 Laurier

1:125,000 MCR 207 Riding Mountain National Park