Chapter 3: Geologic Structure and Landforms
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
3.100: Stabilized Parabolic Dunes on the Assiniboine Delta South of Lavenham
This area is close to the lakeward edge of the
Away from the steeper slopes the vegetation is mainly deciduous woodland 4—identified by rounded shadow shapes—with low bushes between 5. Some land has been cleared for agriculture; the sandy nature of the soils is indicated by the mottled tones in the fields 6. The Assiniboine River 7 flows to the east across the southeast corner with riverine gallery forest along its banks 8. Meander scrolls can be seen in the agricultural land south of the river 9.
A gravel road 10 crosses the south, and paths can be seen in the woodland, several congregating at one point 11 suggesting that something is either assembled at or distributed from this point. The cut line 12 marks a section boundary.
Figure 3.100: Stabilized Parabolic Dunes on the Assiniboine Delta South of Lavenham
Vertical air photograph: A16574-61
Flight height: 9,000 feet a.s.l.; lens focal length: 152.34 mm
Date: June 19, 1959
Scale 1:15,400 (approx.)
Location: Township 9; Range 10 WI
Map sheets: 1:250,000 62G Brandon
1:50,000 62G/10 Treherne