GENERAL GEOLOGY (CRUSTAL DEFORMATION) Flashcards
A general term that refers to the changes in the shape or position of a rock body in response to DIFFERENTIAL STRESS
Deformation
The forces that deform rocks
Stress
Stress applied uniformly in all direction
Confining pressure
Stress applied unevenly
Differential Stress
Different types of Differential stress
Compressive
Change in shape caused by stress
Strain
Stress: Force = Strain :
Resulting Deformation (Distortion) or change in the shape of rock body
Three types of Deformation
Elastic
Temp and Deformation relations
Higher the temperature (below Earth’s Surfcae) the more ductile defromation
The Lower the temp (at or near surface) Rocks are brittle and tends to fracture
Confininig Pressure Effects on Rocks
The more the pressure the more rocks becomes stronger and harder to break since it is being squeezed and tend to BEND rather than Fracture
Weakest naturally Occuring solid to exhibit Ductile Flow
Glacial Ice
What type of deformation is exhibited by Strong Rocks such as Igneous and Met qtz-rich rocks
Brittle
Type of deformation exhibited by weak sed rocks that contain zone of weaknesses such as foliations
Ductile
Strong Rocks:Brittle = Weak Rocks
Ductile
Why is there salt diapirs
Because of the ductile flow of rock salt
Tectonic Forces Slowly Applied: Ductile = ________ : Fracture
Tectonic Forces Swiftly Applied
Series of Wave Like Undulations of Rocks
Folds
Type of Differential Stress that creates folds
Compressional
Imaginary axis where each layer is bent during folding
Hinge line or hinge
A surface that connects all hinge lines
Axial Plane