Artificial Outcrops Give Real Experience in Interpreting a Geologic History: The CMUland Group Project for Historical Geology Courses

Abstract

A basic goal of historical geology courses is for students to gain an understanding of the methods, theories, and logic used in interpreting geologic histories. This is traditionally taught as a series of individual, isolated lessons in identification of rocks, fossils, and sedimentary structures and interpretations of radiometric dating, sequences of events, past depositional environments, and past tectonic events. A supplemental project incorporating these lessons teaches students to evaluate different types of data and use critical thinking to reconstruct a geologic history. Here, a semester-long, group project has been developed that allows students to use their lab- and classroom-honed skills on real rocks in a field setting. Our “field area” includes 11 artificial outcrops, representing six rock types. Students must: (1) identify rock types and fossils; (2) calculate radiometric ages; (3) recognize stratigraphic contacts, geologic structures, and cross-cutting relationships; and (4) critically evaluate this data to give a chronological history of past environments, tectonic events, and even climate. Assessment shows that student learning was enhanced greatly as a result. Not only did students acquire more experience and a deeper understanding in the mechanics of historical geology, they also gained an appreciation for the work required to interpret a geologic history.