GLG 111 Lecture Notes - Lecture 7: Headwall, Rubber Band
Document Summary
Before plate tectonics people believed in catastrophism, which is that the earth was shaped by sudden events. Deformation, stress, strain due to cooling and shrinking. Deformation- process by which rocks bend, break, and flow in response to compression, tension, and shearing. Stress- the forces capable of deforming or distorting something. Strain- the measureable change in the shape of something. Elastic deformation- recoverable, like a rubber band: as stress is applied, the material will strain, once the stress is removed, the material returns to its original shape, the chemical bonds are stretched but not broken. Brittle deformation: non-recoverable deformation, some materials will fracture when they surpass their yield strength, once the stress is removed, the material cannot return back to its original shape, chemical bonds are broken. Ductile deformation: non-recoverable, when some materials reach their yield strength, they flow rather than fracture, some chemical bonds are broken, but new bonds are continuously formed. Two broad types of faults, dip-slip and strike-slip.
