folds analysis techniques
Post on 30-Dec-2015
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Folds analysis techniquesGoal: To apply some of the basic geometric techniques for analyzing folds and refolded folds.
1. Foliation bedding intersections
Three cases for overturned fold:a) Bedding upright, dipping more shallowly than
foliation
b) Bedding overturned dipping more steeply than foliation
c) Bedding highly oblique to foliation
2. π-axes and β-axesDefine fold axis using measurements of
bedding from around the fold
Plot on stereonet
Find a fold axis using these bedding
measurements
• 050°, 80°-SE
• 350°, 44°-NE• 088°, 72°-NW
Use both π-axis and β-axis methods
Refolded folds recognition1. Can often be found in outcrop
2. Regional patterns in facing direction
3. Interference patterns
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