GLACIATION

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Lab Questions. Exercise Ch. 13, 1-17, 23-25, 27-30.

Glacier- a mass of flowing land ________ derived from snowfall.

  • Zone of accumulation- where the snow and ice ____________.
  • Zone of abulation (wastage)- where the snow and ice ____________ back.
  • Snow line- an imaginary line dividing the zones of accumulation and abulation for a given year.

Glacial polish- smooth bedrock caused by glacial ________

Glacial scratches- parallel linear grooves in bedrock caused by glacial __________

Till- __________ mixture of rock debris carried and deposited directly by a glacier. It ranged in size from clay to boulders.

Stratified drift- has been ________________ transported by melt water and is sorted

Moraine- an accumulation of till

  • end moraine- pile of sediments deposited at ___________ reach of a glacier's advance.
  • recessional moraine- a ridge of sediments deposited during a temporary _______ of a melting glacier

Crevasses- deep, narrow _____________ in glaciers

  • transverse- ______________ to the flow
  • longitudinal- ___________ with the flow

 

Two major glacier types:

 

Mountain Glaciers

Erosional:

  • horn- steep sided _________-shaped peak produced by erosion by glaciers
  • arete- sharp jagged, _________ edged ridge between two glaciated valleys
  • cirque- _______ shaped depression on a high moutain slope formed by a cirque glacier
  • u-shaped valley- shape of a valley scoured by a glacier
  • hanging valley- a glacial trough of tributary glacier elevated above the _______ trough

Depositional:

  • lateral moraine- a linear pile of rock fragments deposited at the _______ of a glacier
  • medial moraine- a long narrow pile of rock fragments carried on top of the ___________ of the glacier- usually formed when two glaciers meet uphill.
  • tarn- small ________ in a cirque.

 

Continental Glaciers

Depositional:

  • outwash plain- plain formed by _________ like deposition of outwash (stratified drift by meltwater)
  • kettle lake- small lake in glacial drift formed by melting ________ of ice
  • finger lake- long narrow ________ that was cut into bedrock by glacier.
  • esker- long, narrow _________ of drift deposited under a glacier by meltwater.
  • kame- low _________ of stratified drift deposited by meltwater traveling within or on top of a glacier
  • drumlin- an elongated ridge of glacial till deposited under a glacier and elongated with the _________ end of the drumlin pointing the way the ice came.

 

Know the following glacial feature terms (and be able to pick them out on a topographic map!!):

Water features:

  • Finger lake
  • Tarn
  • Kettle lake

Erosional features:

  • Horn
  • Arete
  • Cirque
  • Hanging Valley
  • Glacial polish
  • Glacial scratches

Depositional features:

  • Moraines- lateral, end and recessional
  • Drumlins
  • Erratic
  • Esker
  • Kame