AN INSIDE-JOB MAPPING EXERCISE

Many areas of the U.S. are far from ideal with respect to diversity of geologic features. Colleges and universities with geoscience programs in relatively "sterile" geological regions still need to provide adequate field experiences for majors before their summer field camp. Frequent travel to distant locations for observation or exercises is not an option for many students and faculty.

Wheaton College in the Chicago suburbs has continued to refine a surrogate field exercise for majors in the required stuctural geology course. Instead of driving several hours from campus to visit an area for mapping, students walk to the basement of the science building for a scaled-down model of hypothetical geologic complexity. The recipe for a challenging exercise requires a large floor area, text books (to simulate outcrops and structural orientations) color coded to a set of hand specimens, and accompanying data to suggest a region of great tectonic diversity. Students produce a geologic map, cross sections, chronologic column of lithologic associations, and a report of investigation (R.I.). The report interprets tectonic regimes/terranes as well as constituent structural features. Skills incorporated in the project include use of Brunton compasses to measure orientation data from the text-book outcrops, generation of a properly scaled base map, basic structural analysis, and petrologic-environmental analysis.

Evaluations of the simulated field exercise are quite positive. In particular, participants indicate greater confidence in approaching the real thing during summer mapping projects. Actual field maps and reports from those who have completed the simulation are indeed better overall than those before institution of the simulation.