This page provides a brief outline of, lists the main points of, gives links to figures for, and lists the assigned reading for a lecture in Dr. Bruce Railsback's GEOL 1121 class at the University of Georgia. This page is not intended as a set of lecture notes, and it cannot subsititute for a set of lecture notes. Familiarity with this page alone will not assure satisfactory grades on exams in the course.

Lecture 31 (Wednesday, April 10): Glaciers and Glaciation I.

Brief outline of this lecture:
Basics of glaciation
Alpine glaciers
     Processes
     Erosional results
     Depositional Results
Main points of this lecture:
Glaciers are flowing masses of ice.
Glaciation requires abundant snowfall and cool summers.
Alpine glaciers flow down mountain valleys from ice fields.
Crevasses can form in the upper brittle part of a glacier.
Alpine glaciers have an upstream end in which accumulation of snow occurs and a downstream end in which ablation (loss) of snow and ice occurs.
Alpine glaciers erode valleys to make U-shaped valleys rimmed by sharp ridges called "aretes" and with upper bowl-shaped depressions caled "cirques". Horns are junctions of aretes.
Alpine glaciation increases the relief of a landscape, sculpting steep valley walls, aretes, and horns out of rounded landscapes.
Glaciers carry sediment of a range of sizes within their flowing ice.
Flow of glaciers folds and distorts the layers of ice and sediment within them.
Unsorted sediment deposited by glaciers is called till.
Alpine glaciers deposit till in end moraines, lateral moraines, and medial moraines.

Figures used in this lecture:
Basics of glaciation
Cross-section of an alpine glacier
Features of alpine glaciation
Patterns of glacial ice flow
Reading assignment: Pages 193 to 198 and Glacial Processes.


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Email to Railsback (rlsbk@gly.uga.edu)
Railsback's main 1121 web page
Railsback's main web page
UGA Geology Department web page