Earth Sciences 1022A/B Lecture Notes - Lecture 5: Shear Stress, Syncline, Slickenside
19 Oct 2015
School
Department
Course
Professor
Document Summary
Earth sciences 1022a lecture brief 7 oct 14. Rocks can be deformed to produce structures that can yield energy and ore reserves. Deformation: when rocks are stressed (force on rocks) beyond their strength they change shape, size. Compressional stress - squeezes rocks and shortens earth"s crust circle becomes more elliptical, making thinner. Tensional stress - stretches and lengthens crust circle becomes elliptical but flatter. Shear stress - causes sideways slip of crust strain is what happens to rocks being stressed looks like a deck of cards when pushing the top. (stress is the force, strain the result) Strong rocks tend to fracture while weak rocks tend to flow (in the solid state) however, with enough time even strong brittle rocks will eventually flow. Mapping geologic structures: geologists measure rock structures in outcrops, using. Strike - compass direction of horizontal line on the planar surface of a bed or fault .
