Download Folds - AdrianasWiki

By: Adriana Lukovic
by:
Adriana Lukovic
During the building of
mountains, flat-lying
sedimentary and
volcanic rocks are
often bent into a series
of wavelike patters
called folds.
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http://www.geolab.unc.edu/facult
y/glazner/Images/Structure/Disha
rmonicFolds.jpg
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Some folds are broad, this is when the rock
units are hundreds of meters thick.
Others are very small and microscopic.
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Most folds are the result of compressional
stresses that result in the shortening and
thickening of the crust.
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The two sides of the fold are called limbs.
The line that is along the points of a maximum
curvature of each layer is termed the hinge line,
or just the hinge. (it is parallel to the surface)
The hinge is inclined at an angle known as the
plunge.
The axial plane is an imaginary surface that
divides a fold as symmetrical as possible.
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Anticline- most commonly formed by the
upfolding of rock layers.
Syncline- Downfolds.
Remember it like this, Angels go up, and
Sinners go down.
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Anticline
http://z.about.com/d/geology/1/0/X/L/anticline.jpg
Syncline
http://z.about.com/d/geology/1/0/F/F/syncline.jpg
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Basic folds are described as symmetrical when
the limbs are mirror images of each other.
Asymmetrical- not the same.

Folds do not continue forever, their ends die
out like the wrinkles in cloths. Some folds
plunge because the fold penetrates into the
ground. Both anticlines and synclines can
plunge.
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The End!