BLAW 3201 Chapter : Chapter 9 1
Document Summary
Undeformed terrain- horizontal beds, spherical sand grains, no folds or faults. Deformed terrain- tilted beds, metamorophic alteration, folding and faulting. Deformation results in one or all of the following: Two major deformation types: brittle and ductile. shallow crust. Ductile deformation- rocks deform by flow and folding. Deformation type depends on temperature and pressure. deeper crust. Deformation is caused by stress which is the force applied per unit area across an area. A large force per area results in much deformation. A small force per area results in little deformation. Compression squeezing (greater stress in one direction). Extension pull-apart (greater stress in one direction). Shear blocks of rock sliding past one another. Pressure an object feels the same stress on all sides. Strike horizontal intersection with a tilted surface. Dip angle of surface down from the horizontal. 3-d structural orientation is described by strike and dip. Joints- planar rock fractures without offset that result from extension.
