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Chapter 3: Geologic Structure and Landforms

3.58: An Esker in Northwestern Manitoba

Eskers are linear ridges deposited by water in tunnels in or under ice sheets. Although they are not particularly high—heights are in metres or tens of metres—they are striking features of the landscape of northern Manitoba often running for tens of kilometres across the land seemingly heedless of the underlying topography on to which they have been superimposed.

This photograph taken near the northern border (60°N) of Manitoba is of an area of drift-covered bedrock. An esker 1 runs the whole width of the photo from north to south. This makes it 8 miles (12.9 km) long, but inspection of the 1:250,000 map of the area (64N Kasmere Lake) reveals that it is 20 miles (32 km) long. In the north, the esker forms the western shore of Putahow Lake 2 into which drains the Putahow River 3 after traversing a series of rapids 4 which are bypassed by Husky Portage 5. This esker is not a single ridge; in two places (6 and 7) it splits into two or more ridges. Another smaller esker 8 runs across part of Putahow Lake. In this area and to the north and west the land has a drumlinized appearance 9, several of the mounds poking above the lake level 10.

This area lies within the forest sub-zone of the forest/tundra transition vegetation zone.[i] The vegetation consists of open lichen woodland; dark areas 11 are patches of woodland, whereas light-toned patches 12 are lichen-covered ground.

The dark area in the southeast 13 is a technical defect, either in taking or in printing the photo.

Figure 3.58: An Esker in Northwestern Manitoba

Figure 3.58: An Esker in Northwestern Manitoba

Figure 3.58

Vertical air photograph: A15707-15

Flight height: 30,000 feet a.s.l.; lens focal length: 152.56 mm

Date: July 23, 1957

Scale: 1:57,900 (approx.)

Location of centre point: 59° 53'N, 100° 43'W

Map sheets: 1:250,000 64 N Kasmere Lake

1:50,000 64 N/15 Putahow Lake


[i] See Scott, G. A. J. “Manitoba’s Ecoclimatic Regions” in Welsted, Everitt and Stadel. op. cit. 1996, figure 4.2, 45.