Landforms of British Columbia 1976 - Department of Geography

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