Constructional I LithologyFoldsFaults

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Constructional I Lithology/Folds/Faults
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Regional Physiography
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Lithology

• Relative erodability
• Layered rocks wide range
• Sedimentary
• Volcanic
• Massive rocks narrow range
• Metamorphic
• Intrusive igneous
• Erodability is not absolute
• typically shale gt limestone gt sandstone gneiss

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Lithology/Climate
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Layer-Cake Topography
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Tablelands

• Plateau/mesa/butte/chimney

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Tablelands
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Strike and dip
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Tilted Layer Cakes

• Monoclinal folding
• Feature f(dip angle)
• Cuesta (gentle)
• Hogback (steep)
• Flatiron (very steep and supported)
• Also f(rel. erodability)
• Drainage patterns
• Parallel
• Trellis

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Ridges

• Cuesta ? hogback ? flatiron

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Red Rocks Amphitheater
http//www.testingstuff.com/vacation/200220Family
20Reunion20in20Colorado/html/45.htm
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Contact
Dip
Strike
Dip Slope
Scarp Slope
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Folded Rocks Simplefrom http//www.geog.ouc.bc.
ca/physgeog/contents/10l.html

• Anticline/syncline
• Plunging

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Folded still simple

• Plunging
• Z-folds
• Domes/basins

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Simple folds - drainage

• Contorted
• Metamorphic?
• Inward/outward
• Radial
• Centripetal
• Ringlike - annular

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Folded Rocks - Complex
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Folded Rocks - Complex
Strong
Weak
Strong
dip slope
Weak
scarp slope
Horseshoe Hills
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Metamorphic Rocks
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Normal Faulting
Teton Fault
Fault (and fault line) scarp
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Faulted Rocks
San Andreas Fault
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Rock Mass Strength

• Regression against slope angle
• Intact rock strength
• Weathering
• Joint spacing
• Joint orientation
• Joint widths
• Joint continuity
• Groundwater outflow

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10
30
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7
7
6
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MT examples

• Radial pattern
• Crazy Mountains
• Trellis pattern
• Bob Marshall