Search Textbook

Table of Contents
Foreword
Preface
Glossary

Chapter 3: Geologic Structure and Landforms

3.21: Gully Erosion on the Northern Flank of Turtle Mountain

In southern Manitoba surface run-off is quickly concentrated into specific channels that erode rills and gullies that over time are enlarged into stream valleys.

This photograph is of the northern fringe of Turtle Mountain, south of Deloraine. Turtle Mountain on the Canada/U.S.A. border is an upstanding area of Tertiary bedrock—the youngest bedrock in Manitoba—covered by glacial till. Its northern flank is inclined gently down to the north towards Whitewater Lake and the Souris River. In this area much of the former deciduous woodland has been cleared, although some patches 1 and strings along creek valleys 2 remain. Minor valleys (rills) 3 lead into gullies 4 and then into stream valleys 5. As is usually the case in southern Manitoba, rain splash erosion has produced light-toned hillcrests, particularly noticeable in fallow fields 6.

The area is subdivided according to the DLS system with gravel roads along some of the section lines 7. Three farms are visible 8, and at one, a dugout 9 has been created to improve water supply—certainly for animals and perhaps for human consumption—in this dry area of southwest Manitoba.

Figure 3.21: Gully Erosion on the Northern Flank of Turtle Mountain

Figure 3.21: Gully Erosion on the Northern Flank of Turtle Mountain

Figure 3.21

Vertical air photograph: A19904-147

Flight height: 9700 feet a.s.l.; lens focal length: 152.16 mm

Date: May 28, 1967

Scale: 1:15,500 (approx.)

Location: Township 2, Range 23 WI

Map sheets: 1:250,000 62F Virden

1:50,000 62F/2 Waskada