Structural Geology

Angela Moore

Guilford College
a
Private four-year institution, primarily undergraduate
.

Summary

An introductory structural geology course that includes the study of stress and strain, rheology, qualitative aspects of brittle and ductile deformation processes, and descriptive analysis. Tectonics is also integrated into the course, primarily through field trips and individual case studies focused on petroleum resources.

Course URL:
Course Size:

less than 15

Course Context:

This is an upper division course required for students majoring with a BA or a BS in Geology; on occasion there may be one or two students in the class pursuing an Earth Science minor. We offer this course in alternate years, and the only prerequisites are Physical Geology, Historical Geology, and some proficiency with trigonometry.

Course Goals:

Students should be able to construct cross sections of unfamiliar areas using geologic maps, core data, and (when appropriate) Google Earth.

Students should be able to visualize deformed rocks in 3 dimensions, and successfully demonstrate their understanding by analyzing block diagrams and using visualization software to predict outcrop patterns and cross sections.

Students should be able to quantitatively assess homogeneous strain in hand samples and at the map scale

Students should be able identify specific geologic structures and provide insight regarding their formation.

Students should be able to use stereonets and other graphical tools to plot and analyze structural features

Students should be able to set up a geologic field notebook, record detailed notes on observations at the outcrop scale, and successfully use field equipment to determine the orientation of geologic structures.

Students should be able to analyze field data collected in an unfamiliar area to deduce fundamental structural relationships such as faults, folds, and joint systems.

Students should demonstrate the ability to collect information from peer reviewed resources, summarize the major geologic events of a particular region, and explain how that geologic history relates to the formation, trapping, and extraction of petroleum resources in the area.


How course activities and course structure help students achieve these goals:

The course structure is designed to introduce the quantitative aspects of stress, strain, and rheology early in the course. These fundamental concepts are then applied to explain the resulting form of geologic structures while learning descriptive language.

Course activities are designed primarily to emphasize major concepts and to give students analytical practice during class sessions. Quantitative skills are also frequently introduced during in class activities in small doses, and are then followed up with more intensive homework assignments that build upon that knowledge. Labs are designed to provide more intensive hands-on learning opportunities, including the use of visualization software and Google Earth to help with 3 dimensional conceptualization, virtual mapping exercises, quantitative analysis of strain markers in hand samples, and construction of cross sections using geologic maps.

Three off campus outings are included as part of the class to encourage development of basic field skills; the first is a one day trip to build student confidence in basic rock identification, mineralogy, and to introduce students to the use of a field notebook. The second trip involves observation and analysis of shear sense indicators, passive folds, and shear sense indicators and also involves data collection on the orientation of fractures and fold axes. The data is then analyzed in a subsequent lab session, plotted on Rose diagrams and stereonets, and compared with published studies of the same region. A final trip to the Smoky Mountains gives students the chance to practice their rock and mineral identification skills, see larger scale features, develop a stratigraphic column, and infer major geologic structures based upon their knowledge of rock types, ages, and locations.

As a final integrative project, each student presents a case study on a region with significant petroleum resources, designed to educate their peers on the topic. The entire class reads introductory chapters on petroleum formation, migration, salt tectonics, and the different types of traps before the case studies are started. At least one lab session and one class period are designated as project work days in order to help students find appropriate peer reviewed resources and identify the major points they are going to include. A very detailed rubric is provided for guidance, and extra meetings are set up with individual students to assist them with article interpretation.

Skills Goals

Quantitative skills (in general)
Oral presentations
Use of Excel spreadsheets
Group work
Field work


How course activities and course structure help students achieve these goals:

Quantitative skills are emphasized throughout the course, including the use of trigonometry to solve applied problems in water resource identification, three point problems, basic statistical analysis of strain markers and fracture orientations, and modeling brittle failure along a plane. The level of math skills in our student population varies widely; students are given a homework set on the first day, and the lab session during the first week is dedicated to reviewing the fundamental algebraic and trigonometric functions they will need to have. Students who successfully complete the assignment before the lab period are exempted from the review session if there are no major gaps in their performance. There is still a great deal of student stress and discomfort with the level of math that is required for the course, and we are considering a supplemental short course designed to help eliminate math deficiencies for the lowest performing students.

Although we introduce the use of spreadsheets in the introductory geology course as a valuable tool for data analysis, our students have not generally been confident or proficient in their use upon graduation. We now include at several lab exercises that require the use of Excel in the Structural Geology, Hydrology, and GIS courses in addition to the introductory course.

Students are encouraged to work together during class room activities, and are required to work as teams during most labs and in all field activities. In general, our students work very well together and we often see students helping one another outside of structured class time.

By the time they are juniors or seniors, our students have had to complete numerous oral presentations in lower level courses. The goals of the case study are to teach them how to integrate technical information into their presentation, cover major content points, and to present material at a level appropriate for an audience of aspiring geologists.

Assessment

Because we have such a diverse community of learners, I use a variety of assessment techniques in the course. Most are standard (homework, lab assignments, in class activities, oral presentation, exams) but offer different opportunities for achievement. The average scores on the exams are usually pretty low, but they definitely encourage students to review past material and there are always a few students that do extremely well. Most students do very well on the lab assignments.

Grading
Two in-class exams (2 x 100 points each) 20%
Final Exam (cumulative) 16%
In class participation, activities 5%
Laboratory work 32%
Smokies field trip, participation and analysis 8%
Pilot Mountain field trip, notes/participation 3%
Petroleum region case study 8%
Homework sets 8%

Syllabus: