Folds
Folds
structure produced when an originally
planar surface is bent or curved
Rock breaks = discontinuous deformation
brittle
Rocks flow or fold = continuous deformation
ductile
Fold Terminology
Axial Plane
Axial Surface
Axial Trace
Wavelength and Amplitude
Structural Facing Direction
Syncline vs
Anticline
Mt Kidd, Alberta (courtesy of
Borealisoutdoor.com)
Fold orientation
Fold Style
Flexural Slip folding
Forms in strong/stiff layers with weak
contacts
From Geoff Tanner
Outer arc: joints and/or keystones
Inner arc: thrust faults, folds and/or cleavage
http://ic.ucsc.edu/~casey/eart150/Lectures/Folds/foldingmechanisms.htm
Examples: Disharmonic folds
Wavelength differ
Do thicker layers have
longer wavelengths?
Courtesy of
M. Miller