Chapter 12 Geological Structures Learning Objectives After carefully reading this chapter, completing the exercises within it, and answering the questions at the end, you should be able to: • Describe the types of stresses that exist within the Earth’s crust. • Explain how rocks respond to those stresses by brittle, elastic, or plastic deformation, or by fracturing. • Summarize how rocks become folded and know the terms used to describe the features of folds. • Describe the conditions under which rocks fracture. • Summarize the different types of faults, including normal, reverse, thrust, and strike-slip. • Measure the strike and dip of a geological feature. • Plot strike and dip information on a map. 397