AN INQUIRY-BASED APPROACH TO LEARNING PETROLOGY USING STUDENT-GENERATED DATA

An important objective of science education is to help students develop an understanding of the fundamental methods of the scientific process. However, this goal can be difficult to accomplish without providing authentic scientific experiences. In essence, if students are to acquire the higher order skills necessary for posing questions, constructing explanations, collecting evidence, and testing hypotheses, they must do science. Furthermore, the Learning-For-Use framework (Edelson, 2001) suggests that learning must be motivated by a perceived need for knowledge or skills on the part of the student, that understanding is constructed from experience and instruction, and that knowledge must be organized before it can be applied. Many of these learning stages are facilitated by inquiry-based projects that involve working with data.

The Petrology course at Macalester College is designed around a semester-long project. All laboratory and classroom activities within the course are directed toward understanding and solving a real-world problem, the origin and evolution of the Sonju Lake Intrusion in northern Minnesota. Emphasis is on using multi-disciplinary approaches, modern instrumentation, and student-generated data. The project begins early in the semester when students are provided a suite of rocks, a map, and a lithostratigraphic column from the Sonju Lake Intrusion. Students work as a group to describe and classify the rocks using hand specimens and thin sections. This is followed by detailed petrographic analysis, which provides data about mineral textures, compositions, and proportions. Explanations of the origin and evolution of the intrusion are constructed from the petrographic data and then tested using mineral (SEM-EDS) and whole-rock (XRF) chemical data collected by the students. The explanations of the origin and evolution of the intrusion are further evaluated and revised. Finally, students test their hypotheses using numerical models (MELTS and trace element models) to model their geochemical data. Students present their findings to the rest of the class in oral format and submit written reports. After completing the course, students exhibit improved quantitative skills, reasoning, and understanding of fundamental petrologic processes.