Table of Contents
2: Location, Borders, and Lakes
3: Geologic Structure and Landforms
6: Pre-historic and Early Historic Settlements
7: Survey Systems
8: Southern Hamlets, Villages, and Towns
9: Mennonite and Hutterite Settlements
10: First Nations Settlements
11: Northern Settlements
12: The Southern Cities
13: Mining and Oil Extraction
15: Industry / Manufacturing
16: Water Resources
17: Parks, Recreation, Sports
18: Transport and Communications: Past and Present
19: Legal Issues and Law Enforcement
3: Geologic Structure and Landforms
Click for chapter introduction
Geologic interpretation of images begins with the identification of lineaments, “regional linear features caused by linear arrangement of regional morphological features such as streams, escarpments, and mountain ranges and tonal features that in many areas are the surface expressions of fractures or fault zones.”[i] The emphasis in this section is on geologic structures and landforms, both of which can be easily identified on air photographs and other images.
The sequence followed here is that often found in geomorphology books. Geologic structures and structurally controlled landforms are illustrated first, followed by images of mass wasting and of the results of the agents of erosion—running water, ground water, ice, wind and the sea. The meandering rivers of southern Manitoba are excellent examples of that river form. Several of them have deposited deltas into lakes. The effects of ground water are less easily illustrated, but examples of spring sapping and artesian erosion exist in the south. As all of Manitoba was covered by ice during the latest glaciation, examples of glacial erosion, and especially of glacial deposition, are widespread. Equally impressive are the suite of landforms created by the large glacial lakes that appeared as the ice melted. Glacial spillways, glacial lake deltas, strandlines and flat lake floors are found in many places. Wind action has created dunes on some of the deltas and on glacial outwash deposits. The Hudson Bay coast is rising as a result of isostatic rebound, recovery from the weight of the ice. One result is the existence of strandlines many metres above the level at which they were created. Finally Manitoba’s great lakes are large enough to illustrate many of the landforms normally associated with sea coasts.
[i] Lillesand, T. M. and Kiefer, R. W. Remote Sensing and Image Interpretation (Third Edition). New York: Wiley, 1994, 179.
3.51: The Brandon Hills, Part of an End Moraine South of Brandon
The Brandon Hills—the dark-toned area in the north-centre of the photograph 1—are the western most extension of the Darlingford Moraine that extends eastwards to Pembina Mountain.[i] They represent a period of still stand in the retreat of ice from Manitoba at the end of the last glaciation. The bulk of the hills are composed of west-northwest/east-southeast trending ridges that are best seen in the west 2. These light-toned ridges are grass-covered whereas most of the area is wooded, resulting in dark tones 3. At the eastern end of the hills is a prominent light-toned north/south trending ridge 4 (see figure 3.52).
The sands and gravels that underlie this ridge are exploited in two gravel pits at either end of the ridge 5. Another gravel pit can be seen at the western end of the hills 6. On the distal side (the side away from the ice front) of the hills are several small lakes 7, one of which—Lake Clementi—8 was a favorite destination for day trips from Brandon in the first half of the Twentieth Century. The hills are surrounded by relatively flat land 9, possibly the floor of a small glacial lake. Drainage is to the east, the main waterway being the Little Souris River 10 that can be picked out because of the dark tone of fringing woodland. Another indefinite area of higher land—mainly wooded and therefore dark-toned—exists on the south 11.
Most of the Brandon Hills are covered with woodland, as the topography is too irregular for agriculture, although encroachment by agriculture into the hills has occurred on both north 12 and south 13 sides. On the north this has resulted in soil erosion 14. An anomalous clearing exists in the east 15; local rumour suggests that there was an attempt to build a landing strip for light aircraft.
The wooded hills are surrounded by agricultural land with the checkerboard pattern of the DLS system. Roads follow section lines, but the hills influence their location; PR 340 between Brandon and Wawanesa locally, termed “The Sunshine Highway,” makes four right-angled bends 16 as it passes round the hills to the east. Only one road—the “Hydro Road” 17 that is followed by hydro lines leading south from a thermal power station in Brandon—crosses the hills from north to south. A side road to the east 18 leads to the start of a series of cross-country ski trails. PTH 10 from Brandon (to the north) to Boissevain (to the south) runs along the west side of the area 19.
Figure 3.51: The Brandon Hills, Part of an End Moraine South of Brandon
Vertical air photograph: A24519-179
Flight height: 26,200 feet a.s.l.; lens focal length: 153.22 mm
Date: August 1, 1976
Scale: 1:48,200 (approx.)
Location: Townships 8 and 9; Ranges 18 and 19 WI
Map sheets: 1:250,000 62G Brandon
1:50,000 62G/12 Wawanesa
[i] For a detailed description of the Brandon Hills see Welsted, J., and Young, H. R. “Geology and origin of the Brandon Hills, southwest Manitoba.” Canadian Journal of Earth Sciences, vol. 17, no. 7, 1980, 942-951.