Alpine Glaciation in the Teton Range, NW Wyoming

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Alpine Glaciation in the Teton Range, NW Wyoming
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Glacier Gulch - Horns, cirque of the Teton
Glacier, and U-shaped Valley
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The Grand Teton (Horn), Cirque Headwall, and
Teton Glacier
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On the Surface of the Teton Glacier (Father, Jim
and Sister, Ann, 1971)
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End Moraine of the Teton Glacier

• Note poorly sorted and unstratified deposits of
  till
• Note the dirty ice at the toe of the glacier

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Mt. Moran (Horn) and Cirque Glacier (Falling Ice
Glacier)

• Note the vertical black dike (a basalt-like rock
  called diabase) - pC age
• Note the Cambrian Flathead Sandstone that
  unconformably overlies the Precambrian rocks

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Snowdrift Lake (Avalanche Canyon) - a Cirque Lake
or Tarn
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Waterfalls Canyon

• A glacial stair-stepped valley
• Note the cirque at the head of the valley

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Amphitheater and Surprise Lakes (foreground,
cirque lakes) and Bradley and Taggart Lakes
(moraine-dammed lakes on valley floor)
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The Symmetry Spire Ridge (foreground) and the Mt.
St. John Ridge (background) - Aretes
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Leigh Canyon - An Excellent Example of a Glacial
Trough or U-Shaped Valley
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Cascade Canyon and Jenny Lake - Glacial Trough
and Moraine-dammed Lake

• Imagine the glacier occupying the valley up to
  the break in slope on Storm Point (left entrance
  to canyon), spilling onto the valley floor, and
  ending at the terminal moraine that dams Jenny
  Lake

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Jacksons Hole From Disappointment Peak

• Covered with glacial outwash and a growth of
  sagebrush
• Ridge of trees center-right is Timbered Island,
  an older Pleistocene moraine
• Porous and permeable outwash will not support
  forest growth, unlike more clay-rich morainal
  deposits

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Abandoned Pleistocene Braided Channels 1 mile
North of Moose, WY

• Note terraces along margins of abandoned channels
• Note end moraine (the ridge with trees, left
  center of photo)

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Pleistocene Terraces of the Snake River

• Two episodes of downcutting are represented
• Climatic rejuvenation of river system - when
  glaciers melt, rivers draining the retreating ice
  have greater discharge, resulting in downcutting.
  When ice advances, discharge is less, and river
  deposits material to form new floodplain