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Chapter 3: Geologic Structure and Landforms

3.95: Raised Strandlines North of the Lower Churchill River

At this location, about 45 miles (72 km) from its mouth, the Churchill River 1 is still almost 200 feet (61 m) above sea level. The river flows in a remarkably straight steep-sided channel about 0.4 kilometres (1,312 feet) wide with rapids along its course 2.[i] North of the Churchill is a prominent arcuate strandline 3 that is almost 400 feet (122 m) above present sea level. The north end of the strandline 4 is light-toned, suggesting sand or gravel at the surface, whereas in the south there are several distinct ridges, darker in tone 5, possibly covered by vegetation. To the west—further inland and at a higher elevation—are several other minor strandlines 6. The Churchill receives a left bank tributary, Chasm Creek 7, near the southern edge of the photo. Further north, Robson Creek 8 flows to the east, its direction in one stretch being determined by the major strandline 9. Another river further north is also deflected by the strandline, in this case to the north 10. Several straight river segments 11 and angular bends 12 suggest some structural control of the drainage.

This area is located within the open lichen woodland vegetation area of Manitoba; the lichens account for the light-toned areas 13 whereas the darker areas especially in the southwest 14 are tree covered. Many dark-toned lakes 15 dot the surface, but in the southeast specular reflection produces light tones 16.

Figure 3.95: Raised Strandlines North of the Lower Churchill River

Figure 3.95: Raised Strandlines North of the Lower Churchill River

Figure 3.95

Vertical air photograph: A17406-8

Flight height: 30,000 feet a.s.l.; lens focal length: 88.28 mm

Date: July 31, 1961

Scale: 1:100,000 (approx.)

Location of centre point: 58° 05'N, 94° 58'W

Map sheets: 1:250,000 54 L Churchill

1:50,000 54L/2 Red Head Rapids


[i] This photograph was taken before the diversion of a large proportion of the flow of the Churchill River into the Nelson River to increase the flow of the latter for HEP generation. The Churchill now probably occupies only a proportion of the channel shown in the photo.