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
3.69: The Arden Ridge East of Birnie
Some of the
Drainage in the area is generally from the higher land in the west to lower land in the east. Several small creeks can be seen 6, one of which is deflected south by the Arden Ridge 7. However, Birnie Creek 8 in the north flows across the strandlines without interruption, but in the northeast it has been straightened 9 to improve its flow rate. One small creek has been dammed to create a reservoir 10 for water supply at a neighbouring farm. Land between the two sets of strandlines is dry; consequently, much of it has been left with a scrub cover 11. In order to improve water supply—mainly for use by cattle—numerous dugouts (small black rectangles on the photo) have been excavated 12.
As is usually the case with photos of southern
Figure 3.69: The Arden Ridge East of Birnie
Vertical air photograph: A15225-11
Flight height: 20,000 feet a.s.l.; lens focal length: 152.26 mm
Date: May 24, 1956
Scale: 1:37,300 (approx.)
Location: Townships 16 and 17; Ranges 14 and 15 WI
Map sheets: 1:250,000 62J Neepawa