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1.4 Understand how moving ice acts as an agent of erosion and deposition. (Chap. 2). There are two types of glaciation. Alpine Glaciation Continental Glaciation. Distinguish between the terms alpine glaciation and continental glaciation. (P.32). Alpine Glaciation.
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1.4 Understand how moving ice acts as an agent of erosion and deposition. (Chap. 2) There are two types of glaciation. • Alpine Glaciation • Continental Glaciation
Distinguish between the terms alpine glaciation and continental glaciation. (P.32)
Alpine Glaciation • Alpine glaciers form high in mountain valleys; above the snow-line
C E D B A Alpine Glaciation
Continental Glaciation • Continental glaciers cover parts of continental land masses; ex Greenland
Similarities Both move and cause erosion Both change the landscape Both developed in constantly cold < 0 0C Differences Location Alpine = mountain Continental = earth poles Size Alpine = smaller Continental = larger Distinguish between the terms alpine glaciation and continental glaciation. (P.32)
Define the terms outwash plain, terminal moraine, erratics, drumlins & eskers. (P. 33 Q.12) • These features are associated with continental glaciation. • See picture p. 34
Outwash plain • Similar to a river delta • Melt water flowing from the glacier deposits silt • Deposited in layers • Small particles carried further away • Larger particles drop closer to the glacier Outwash plain
Continental…Outwash plain Outwash Plain
Terminal moraine • Heap or ridge of bulldozed gravel that marks the end of the forward motion of a glacier • As glacier retreats it deposits debris/gravel • P. 34
Continental…Terminal Moraine Terminal Moraine Outwash Plain
Erratics • Large boulders that were transported long distances and dropped • They now sit in a region and look very much out-of-place. • P. 34
Continental…Erratic Terminal Moraine Outwash Plain Erratic
Drumlins p. 34 • Egg shaped hill • Formed under glaciers • Sloped or Pointy end points in direction of ice flow
Drumlins p. 34 • Formation • Ice melts under glacier • Deposits of gravel made • Glacier moves forward • Deposits are bull-dozed along and catches up in rough areas forming piles or drumlins.
Drumlin What direction did the glacier move?
Continental…Drumlin Drumlins Terminal Moraine Outwash Plain Erratic
Esker p. 34 • Long deposits of eroded glacial material • Formed by sub-glacial streams that deposit material like all rivers. • Highways of the North!!
Continental…Esker Drumlins Terminal Moraine Esker Outwash Plain Erratic
Examine evidence for the direction of movement of glaciers. (P. 34 question # 13) • Sloped end of drumlin • Location of terminal moraine • What is direction of glacier movement in this picture?
Define the terms cirque, arête, hanging valley, lateral moraine, and terminal moraine. (P. 36) • These features are associated with alpine glaciers
Alpine glaciers • Alpine glaciers are like very slow moving rivers of ice flowing down high mountain valleys.
Cirque (p. 36) • a circular hollow cut into bedrock during glaciation • Side and back walls are steep but front wall opens downward
Cirque - How formed? • Alpine glacier freezes onto mountain valley and as is proceeds it plucks rock from the mountain top leaving the cirque shape.
C E D Cirque B A
Arête p. 36 • Steep, jagged, narrow, knife edged ridge between two cirques or glacier valleys.
Arete C E D Cirque B A
Truncated Spur • Blunt-ended ridge of rock jutting from the side of a glacial trough, or valley
Arete C E D Cirque B Truncated spurs A
Horn or Pyramidal Peak • is a mountaintop (peak) that has been modified by the action of ice during glaciation.
Arete C E Horn D Cirque B Truncated spurs A
Hanging Valley • A high level tributary valley from which the ground falls sharply to the level of the lower, main valley. • The depth of the lower valley is due to more severe glaciation. Most noticeable once glacier has melted!
Hanging Valley in Newfoundland • Hanging Valley in Gros Morne National park . • Trout River pond
Lateral Moraine • Moraine means 'rock waste'.It is also known as glacial till • Lateral Moraine is the land-form deposited at the side of a glacier • Debris/waste rock drops off the side of the mountain as the glacier moves forming a ridge of debris at the outer-sides of the glacier.