Geologic map + fault mechanics problem set

John Singleton, George Mason University

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Summary

This exercise requires students to answer some questions about stress and fault mechanics that relate to geologic maps. In part A) students must draw a cross section and Mohr circles and make some calculations to explain the slip history and mechanics of two generations of normal faults. In part B) students interpret the faulting history and fault mechanics of the Yerington District, Nevada, based on a classic geologic map and cross section by John Proffett. keywords: geologic map, cross section, normal faults, Mohr circle, Coulomb failure, Andersonian theory, frictional sliding, Byerlee's law

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Context

Audience

undergraduate required course in structural geology

Skills and concepts that students must have mastered

This exercise should follow previous exercises and lectures that introduce stress, Mohr circles, Andersonian theory, Coulomb failure, and frictional sliding/Byerlee's law. The cross section for this lab is fairly simple, but this is not intended to be a lab on how to draw a cross section.

How the activity is situated in the course

stand-alone exercise that integrates and builds on a range of previous lecture and lab material

Goals

Content/concepts goals for this activity

Some students find fault mechanics fairly abstract. This lab/exercise attempts to relate basic stress concepts and fault mechanics (Andersonian theory, Mohr-Coulomb failure, frictional sliding) to a geologic map, highlighting how this theory can help us understand the geology of some areas. The exercise is somewhat eclectic, integrating map and cross section interpretation skills with traditional fault mechanics problems. This lab also sets the stage for lectures/discussion on normal faults and the mechanics of slip on low-angle normal faults

Higher order thinking skills goals for this activity

Students are required to think about structures in 3-D and to integrate ideas learned in several previous lectures/labs.

Other skills goals for this activity

Description and Teaching Materials

Geologic map - fault mechanics problem set with key (Acrobat (PDF) 1.4MB Jul15 12)
Geologic map - fault mechanics problem set (Acrobat (PDF) 1.2MB Jul15 12)


Teaching Notes and Tips


Assessment

References and Resources