GEO 1111 Lecture Notes - Lecture 9: Structural Geology, Elastic-Rebound Theory, New Madrid, Missouri

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: David Schneider

Document Summary

That which change motion or orientation of a body. Rocks behave as elastic, ductile or brittle depending on: amount & rate stress. Low strain rate promotes ductile deformation: type of rock. Mechanically weak rocks tend to deformation through ductile processes: temperature & (confining) pressure. Folds: wave-like undulations in rock layers, mm-km scale features, result from horizontal or lateral compressional forces, described by the orientation of axial. Plane circular or slightly elongated structures: dome, upwarped displacement of rocks, basin, downwarped displacement of rocks. Brittle deformation (rupture) & faulting loss of cohesion of a body under the influence of deforming stress: usually occurs along sub-planar surfaces that separate zones of coherent material. Joints are fractures or cracks in bedrock along which essentially no movement has occurred: multiple parallel joints are called joint sets. Faults are fractures in bedrock along which movement has occurred: considered active if movement has occurred within the last 15,000 years (last ice age)