Landforms of British Columbia 1976 - Department of Geography
Landforms of British Columbia 1976 - Department of Geography
Landforms of British Columbia 1976 - Department of Geography
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The Front Range structures consist <strong>of</strong> a succession <strong>of</strong> overthrust sheets lying<br />
between southwesterly dipping faults which slice the great limestone formations <strong>of</strong><br />
the Upper Devonian and Carboniferous into a number <strong>of</strong> blocks. Erosion <strong>of</strong> these<br />
geologically complex blocks has produced the numerous parallel ranges which con-<br />
stitute the Front Ranges, each range being composed mostly <strong>of</strong> thick southwesterly<br />
dipping limestones. The resistant limestone forms 30. to 45-degree dip slopes<br />
facing southwest, and steep scarp slopes facing northeast. Late Pleistocene cirqw<br />
glaciation has accentuated the sharpness <strong>of</strong> the topography <strong>of</strong> the east- and<br />
northeast-facing scarps, The Front Ranges ,form striking mountain units that rise<br />
abruptly above broad glaciated longitudinal valleys which separate them.<br />
In the south many <strong>of</strong> the valleys separating individual ranges arc underlain<br />
by s<strong>of</strong>t, more easily eroded sandy and shaly rocks <strong>of</strong> Jurassic and Cretaceous age.<br />
These low areas <strong>of</strong> Mesozoic rock for the most part are too small to be separately<br />
designated. However, west <strong>of</strong> Erickson Ridge and Taylor Range and east <strong>of</strong> the<br />
range flanking the west side <strong>of</strong> the Elk River there is a structural basin in which<br />
Jurassic and Cretaceous rocks occur, This is the Fernic Basin (see? Plate XXXIVA),<br />
which has a length <strong>of</strong> 65 miles and a maximum width <strong>of</strong> 15 miles near the south<br />
end. The east and west boundaries <strong>of</strong> the Fernie Basin are fault-controlled.<br />
North <strong>of</strong> the railway bend at Natal the Fernie Basin is very largely the valley<br />
<strong>of</strong> the Elk River with flanking ridges such as Natal Ridge (7,000 feet) and Fording<br />
Mountain (6,000 feet) along the eastern side. South <strong>of</strong> Natal the basin widens,<br />
and elevations <strong>of</strong> 7,000 feet are reached on Fernie Ridge and east <strong>of</strong> the head <strong>of</strong><br />
Coal Creek. There the rocks lie in a gentle open syncline. The gently sloping<br />
uplands at elevations above 5,000 feet are being incised by tributaries <strong>of</strong> the Elk<br />
River, Michel and Morissey Creeks, and the Flathead River. The general aspect<br />
<strong>of</strong> the Fernie Basin is one <strong>of</strong> moderate relief, in which gently sloping uplands<br />
descend by more abrupt lower slopes to the levels <strong>of</strong> the Elk and Flathead Rivers<br />
and their tributaries.<br />
[References: Leech, G. B., “ Geoloa, Fernie (West Half),” Geol. ,Surv.,<br />
Canada, Map 11-1960; Price, R. A,, “ Fernie Map-area~(East Half) ,” G&. Surv,,<br />
Canada, Paper 61-24.1<br />
[Photographs: B.C. 891:73; R.C.A.F. T3lR:l75; R.C.A.F. T3lL:l64,<br />
167, 174, 184, 196.1<br />
The ~o&wa~~ (~&ern~ Ranges <strong>of</strong> the Rocky Mountains (see Plate XXXIVn)<br />
lie between the Rocky Mountain Trench and the Kootenay-White River lineament.<br />
From the mouth <strong>of</strong> the Kicking Horse River to the Bull River the length <strong>of</strong> these<br />
ranges is 140 miles and their maximum width is 18 miles. The Kootenay (Western)<br />
Ranges include the Brisco, Stanford, and Hughes Ranges, The ranges are.<br />
characterized by geologic structures <strong>of</strong> very great complexity, unlike structures<br />
known elsewhere in the Canadian Rockies.<br />
The Stanford Range is described as being representative <strong>of</strong> the ranges at<br />
large. The Stanford Range is dominated by a number <strong>of</strong> northwestefly trending,<br />
almost parallel structural ridges, These are deeply incised and partly dissected by<br />
transverse valleys which contain trunk streams or tributaries to streams that occupy<br />
the longitudinal valleys between the ridges. The ridge tops are at elevations<br />
between 5,200 and 8,000 feet and range in character from some that are broad<br />
and rounded to others that are narrow and almost knife-edged.<br />
“Within the range the local relief is from about 2,SOi3 to 4,000 feet, but,<br />
adjacent to the Rocky Mountain trench or Kootenay River valley, the local relief<br />
is commonly about 4,500 feet and may be as much as 6,000 feet, The highest<br />
summit in the Stanford Range, Indianhead Mountain, has an elevation <strong>of</strong> about<br />
87