lecture 22 Flashcards
Erosion
Rock fragments in the glacier act like sandpaper on the bedrock below
Large rocks in the glacier gouge lines in the bedrock called…
Striations
Roche moutonee
Asymmetric bedrock hills shaped be ice
Before glaciation how are the river valleys shaped
Like V’s
Before glaciation what elevation are the tributary mouths compared to the trunk stream
The same
During glaciation
valley fills with ice, undergoes extensive erosion and becomes much steeper
After Glaciation
Landscape now has U-shaped valleys, hanging valleys, cirques, aretes, horns
Cirque
A bowl shaped basin eroded by a cirque glacier, after the ice melts it is filled with a tarn lake
A horn
Peak formed by three or more cirques that coalesce
Hanging valley
Results from the intersection of a tributary glacier with a larger valley
Fjords
U- shaped glacial troughs that have become flooded by the sea
Transport
Ice picks up rock fragments at the base which deepens valleys
Depostition
Rock and setiment that build up at the front of the glacier = TERMINAL MORAINE
Deposition
Lateral moraine = rock build up at the edges, medial moraine = rock build up in the middle
Lakes form by melt water pooling behind moraines as glaciers retreat
yup
What marks the furthest extent of glaciers
Moraines
Erratic boulders, very large boulders that have traveled a long way, could have been deposited by ice
Deposition
Eskers
Long curvy(sinuous) ridges of sand and gravel, form as meltwater channels within or below ice
