GEOL 1010 Chapter 10: Crustal Deformation
11 Nov 2018
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Document Summary
Rocks deform when the stress acting on a rock body exceeds its strength. Confining pressure is when stress is applied equally in all directions. Differential stress is when stress is applied unequally in different directions, three kinds. Compressional stress is when differential stress is applied inward on a rock. Tensional stress is when differential stress is applied in outward directions on a rock (i. e. plates moving apart, basin and range province). Shear stress is when differential stress is applied in opposite directions on a rock, causing the rock to shear. Strain is when a rock"s shape is changed, it is the result of stress (the distortion after stress). Elastic deformation is stress that is recoverable, meaning the rock can snap back into its original shape and size. Brittle deformation is when a rock"s stress limits are exceeded and the rock begins to break into smaller pieces. Most rocks exhibit brittle behavior 10 km deep.
