Lecture 13 (Friday, February 15 - Monday, February 18): Folds
Brief outline of this lecture:
Domes and Basins
Complexities of Folding
Main points of this lecture:
Simple Folds can be categorized as anticlines and synclines.
The oldest layers are in the center of a anticline, whether it's seen in cross-section or map view.
The youngest layers are in the center of a syncline, whether it's seen in cross-section or map view.
Antlclines and synclines can plunge in one direction or in two directions.
Doubly plunging anticlines form domes; doubly-plunging synclines from basins.
Folds exist at many scales, from hand sample (or smaller) to regional.
Folding requires internal deformation of the folded layers.
One result of that deformation is fracturing when brittle layers are folded.
Another result is thinning in fold limbs and thickening in fold hinges.
Figures used in this lecture:
A geologic map of Michigan
A geologic map of Tennessee, Kentucky, southern Illinois, southern Indiana, and southern Ohio
A labeled map of Domes and Basins in Tennessee, Kentucky, southern Illinois, southern Indiana, and southern Ohio
A cross-section from Tennessee to central Illinois
Problems in Folding - Part 1
Problems in Folding - Part 2 - the results
Reading assignment: None.
Email to Railsback (firstname.lastname@example.org)
Railsback's main 1121 web page
Railsback's main web page
UGA Geology Department web page