Glaciers

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GLACIAL EROSIONAL FEATURES

1) Cirque - horseshoe-shaped, steep-walled glaciated valley head

2) Horn - jagged peak formed in areas where mountain glaciers radiate away from a summit area & have removed most of the latter

3) U-shaped Valley - steep sides & flat floor

4) Hanging Valley - tributary valley where floor is higher than the main valley & can also have waterfalls

5) Fjords - narrow glacial valley partly submerged by the sea

6) Arête - jagged thin rock wall or ridge separating 2 glaciated valleys, generally near their head

7) Truncated Spur - triangular facet where the lower end of a ridge has been eroded by glacial ice

8) Tarn - alpine rock-basin lake commonly resulting from differential glacial scouring

9) Pater Noster Lakes - a chain of small lakes in a glacial trough that occupy basins created by glacial erosion; from high above or on a map they resemble a string of beads

10) Col - pass

11)

Roches Mountonnées

- small streamline hills carved by the ice from protruding bedrock knobs; can be used to indicate the direction of glacial flow because the gentler slope is on the side from which the ice advanced

12) Glacial Striations - long grooves & scratches made by a glacier on the rocks it carries or on the bedrock over which it moves; if the striations are large called grooves

13) Chattermarks - horseshoe-like indentations in the polished bedrock

14) Glacial Polish - polishing of surfaces

GLACIAL DEPOSITIONAL FEATURES

1) Drift - sediments of glacial origin

2) Till - unsorted & unstratified (no layering, completely random) material deposited directly by glacial melting

3) Outwash Plain - sediment deposited by water outwash from the front of a glacier, is stratified

4) Moraine - a body of till either being carried on a glacier or left behind after a glacier has receded a) Terminal (End) Moraine - deposits left at the front of the glacial ice after glacier receded, marks farthest advance of the glacier b) Lateral Moraine - deposits of till that mark the side of glacier or valley, larger on the north & east sides because these sides face the warm afternoon sun c) Medial Moraine - found down the middle of a valley, caused by the merging of two lateral moraines d) Ground Moraine - everything to the north of a terminal moraine; has small amounts of sediment & is generally formless e) Recessional Moraine - end moraines that were created as the ice front occasionally stabilized during retreat

5) Rock Flour - finely ground-up rock produced by the grinding effect of a glacier, covers much of the surface of an outwash plain

6) Drumlin - hill composed of glacial till molded by flowing ice into a streamlined form

(ex: Bunker Hill)

7) Kettle - depression created when large block of ice incorporated into the till melts

8) Esker - narrow, sinuous ridge of stratified sediment probably deposited by streams flowing in ice tunnels beneath a glacier

9) Kame - hill composed of sorted & layered glacial outwash sediment that was in most cases deposited either in a hole in the ice or as a fan at the front of the glacier

10) Erratic - boulder which was moved from its original place & differs from the underlying bedrock

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