Changes

</gallery>

</gallery>

[[File:Structural_Geology_Fig-3.6.png|thumb|Fig 3.6 DIFFERENTIAL STRESS]]

[[File:Structural_Geology_Fig-3.6.png|300px|thumb|Fig 3.6 Differential stress]]

'''Strength'''

'''Strength'''

* Temporary change in shape or size that is recovered when the deforming force is removed

* Temporary change in shape or size that is recovered when the deforming force is removed

[[File:Structural_Geology_Fig-3.7.png|thumb|Fig 3.7]]

[[File:Structural_Geology_Fig-3.7.png|center|300px|Fig 3.7]]

'''Ductile (Plastic) Deformation'''

'''Ductile (Plastic) Deformation'''

* Permanent change in shape or size that is not recovered when the stress is removed

* Permanent change in shape or size that is not recovered when the stress is removed

* Occurs by the slippage of atoms or small groups of atoms past each other in the deforming material, without loss of cohesion

* Occurs by the slippage of atoms or small groups of atoms past each other in the deforming material, without loss of cohesion

[[File:Structural_Geology_Fig-3.9.png|thumb|Fig3.9]]

File:Structural_Geology_Fig-3.9.png|Fig3.9

'''Brittle Deformation (Rupture)'''

'''Brittle Deformation (Rupture)'''

* Usually occurs along sub-planar surfaces that separate zones of coherent material

* Usually occurs along sub-planar surfaces that separate zones of coherent material

[[File:Structural_Geology_Fig-3.10.png|thumb|fig 3.10]]

[[File:Structural_Geology_Fig-3.10.png|center|300px|fig 3.10]]

'''Factors that affect deformation'''

'''Factors that affect deformation'''

'''''The variation of these factors determines if a rock will fault or fold.''''

'''''The variation of these factors determines if a rock will fault or fold.''''

[[File:Structural_Geology_Fig-4.0.png|thumb|Fig 4.0]]

[[File:Structural_Geology_Fig-4.0.png|center|300px|Fig 4.0]]

Brittle Failure  

Brittle Failure  

* (scale - from mm to tens of km)

* (scale - from mm to tens of km)

   

   

[[File:Structural_Geology_Fig-4.1.png|thumb|Fig 4.1]]

[[File:Structural_Geology_Fig-4.1.png|center|300px|Fig 4.1]]

===Anticlines and Synclines===

===Anticlines and Synclines===

* Synclines are folds in which each half of the fold dips toward the trough of the fold.  You can remember the difference by noting that anticlines form an “A” shape, and synclines form the bottom of an “S.”  

* Synclines are folds in which each half of the fold dips toward the trough of the fold.  You can remember the difference by noting that anticlines form an “A” shape, and synclines form the bottom of an “S.”  

   

   

[[File:Structural_Geology_Fig-4.3.png|thumb|Fig 4.3 Folding and surface rock pattern]]

[[File:Structural_Geology_Fig-4.3.png|center|300px|Fig 4.3 Folding and surface rock pattern]]

After erosion has occurred, geologists can use the patterns of rocks on the surface to determine where anticlines and synclines exist.  In the block diagram above, the top of the block represents the ground surface and what would be shown on a geologic map. The sides of the block show the underground geology. In anticlines, as seen on the ground, the oldest rocks are in the center of the fold.  In synclines, the youngest rocks are in the center of the fold.

After erosion has occurred, geologists can use the patterns of rocks on the surface to determine where anticlines and synclines exist.  In the block diagram above, the top of the block represents the ground surface and what would be shown on a geologic map. The sides of the block show the underground geology. In anticlines, as seen on the ground, the oldest rocks are in the center of the fold.  In synclines, the youngest rocks are in the center of the fold.

   

   

[[File:Structural_Geology_Fig-4.4.png|thumb|Fig 4.4 Folds in limestone picture.]]

[[File:Structural_Geology_Fig-4.4.png|center|300px|Fig 4.4 Folds in limestone picture.]]

This intensely folded limestone from Highland County shows how anticlines and synclines typically occur together.  These sharp folds are called "chevron" folds.

This intensely folded limestone from Highland County shows how anticlines and synclines typically occur together.  These sharp folds are called "chevron" folds.