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 28 (Wednesday, April 3, 2002): Streams, and Rivers

Brief outline of this lecture:
Alluvial fans
Streams and rivers
Meandering streams

Main points of this lecture:
Streams emerging from mountains onto plains commonly deposit sediment in alluvial fans.
Streams and rivers form a continuum from braided to meandering morphologies.
Coarse sediment and sparse surrounding vegetation favor formation of braided streams; fine sediment and dense surrouding vegetation favor formation of meandering streams.
Meandering streams can loop back on themselves, cutting off their flow and leaving behind ox-bow lakes.
Meandering streams migrate laterally toward the outside of their meanders, leaving behind fining-upward sequences of sediment in their point bars.
Rivers can establish floodplains and then cut deeper, leaving behind high relict floodplains called terraces.

Figures used in this lecture:
A sketch and a photograph of alluvial fans
Meandering vs. braided rivers
River meanders
River deposits
River terraces
Meander cut-off and formation of an ox-bow lake

Reading assignment: Chapter 6.

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