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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Sea cliff-the wave-eroded cliff on the shoreward margin <strong>of</strong> a beach or terrace that<br />
is subject to wave attack. See Plate XLVA.<br />
Serrate-a saw-tooth pr<strong>of</strong>ile, as <strong>of</strong> a ridge.<br />
Sheeting-gently dipping joints that are essentially parallel to the ground surface;<br />
they are more closely spaced near the surface and become progressively farther<br />
apart with depth. Sheeting is especially well developed in granitic rocks.<br />
Shield volcano-a broad, gently sloping volcanic cone <strong>of</strong> flat domical shape, usually<br />
several tens or hundreds <strong>of</strong> square miles in extent, built chiefly <strong>of</strong> overlapping<br />
and interfingering basaltic lava flows. See Plates XXVIA and XVIIB.<br />
Snowline-the limit <strong>of</strong> height at which snow is permanent throughout the year.<br />
Stock-a body <strong>of</strong> plutonic rock that covers less than 40 square miles; it commonly<br />
has steeply dipping contacts.<br />
Strandflat-a low coastal platform that abuts higher terrain on the landward side;<br />
it may be partly submerged and its altitude depends partly on recent vertical<br />
movements <strong>of</strong> the coast. See Plate VIA.<br />
Strike-the bearing <strong>of</strong> the intersection <strong>of</strong> an inclined plane with the horizontal.<br />
Structural-pertaining to, part <strong>of</strong>, or consequent upon geologic structure, as a struc-<br />
tural valley.<br />
Subsequent stream-one that has grown headward by retrogressive erosion along a<br />
belt <strong>of</strong> weak structure; used also for streams which have been thus developed<br />
in one cycle and persist in the same course in a following cycle.<br />
Syncline-a fold in rocks in which the strata dip inward from both sides toward the<br />
axis; the opposite <strong>of</strong> anticline.<br />
Talus, wee-the heap <strong>of</strong> coarse waste at the foot <strong>of</strong> a cliff or a sheet <strong>of</strong> waste cov-<br />
ering a slope below a cliff. See Plate XXIXB.<br />
Tarn-small mountain lake or pool occupying an ice-gouged basin on the floor <strong>of</strong><br />
a cirque-a cirque lake. See Plate XB.<br />
Tectonic-pertaining to the rock structure and external forms resulting from the<br />
deformation <strong>of</strong> the earth’s crust.<br />
Terrain-tract or region <strong>of</strong> ground immediately under consideration.<br />
Thrust fault-a reverse fault that is characterized by a low angle <strong>of</strong> inclination to<br />
the horizontal. See overthrust.<br />
Till-non-sorted and non-stratified glacial stony clay.<br />
Timberline-the height on mountains above which there are no trees.<br />
Trellis drainage-arrangement <strong>of</strong> parallel tributary streams generally flowing at right<br />
angles into a trunk stream.<br />
Tuya-flat-topped, steep-sided volcano consisting <strong>of</strong> horizontal beds <strong>of</strong> lava capping<br />
outward-dipping beds <strong>of</strong> fragmental volcanic rocks. See Plate XV&<br />
Under%-a stream is underfit when it is too small to have eroded the valley it now<br />
occupies. See Plate XLA.<br />
UplandsAlevated land surfaces, exclusive <strong>of</strong> valleys, that are represented by flat-<br />
topped ridges and gently sloping areas. They are remnants <strong>of</strong> an erosion SW-<br />
face produced during an earlier erosion cycle and subsequently dissected. See<br />
Plate XVI.4.<br />
Uplift-elevation <strong>of</strong> any extensive part <strong>of</strong> the earth’s surface relative to some other<br />
part; opposed to subsidence.<br />
Upwarp--an area that has been uplifted, generally as a broad dome or anticline.<br />
U-shaped valley-a glacial trough or glaciated valley having a flat floor and ex-<br />
tremely steep sides, with a cross-ection like the letter “ U.” See Plate XLIIB.<br />
Valley train-the outwash material deposited by the stream in the valley below a<br />
glacier. See Plate 11.4.<br />
Volcanism, volcanic activity-the natural processes resulting in the formation <strong>of</strong><br />
volcanoes, volcanic rocks, lava flows, etc.<br />
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