MICROSCOPES, MAGMA DIFFERENTIATION, AND METAMORPHISM: A SYNTHESIS OF EVOLVING COURSE STRUCTURE, ASSIGNMENTS, AND ASSESSMENTS IN AN UNDERGRADUATE PETROLOGY COURSE

The Introduction to Petrology course at JMU is a combined lecture and lab class required for the BS degree in Geology that covers igneous and metamorphic petrology, thermodynamics, and whole-rock geochemistry. Over the span of twenty-two semesters the course has maintained four principle learning objectives intended to prepare students for independent thinking in upper-level courses, a capstone field course, and careers in the geosciences. In contrast, the course schedule, assessments, textbook resources, and assignments were modified to accommodate student needs, course enrollment, and external variables such as curricular changes and the pandemic. Here, I track changes in the petrology course through time allowing intentional reflection on past changes and providing a framework for future changes to improve student learning. The semester schedule alternated between linear and spiral learning progressions. The linear semester progressed through igneous and then metamorphic petrology skills and concepts, developing each topic sequentially. The spiral learning progression presented core skills and concepts during the first half of the semester and revisited these concepts in increasingly complex case studies during the second half of the semester. Summative assessments ranged from two to four comprehensive exams, to separate lab and lecture exams, to quizzes focusing on key skills needed to progress through the semester. Formative assessments shifted from homework assignments to in-class activities. To accommodate student needs, field trips changed from two mandatory trips per semester, to choosing one or two trips from several including accessible options such as conferences or workshops. The development of online educational resources and larger enrollments resulted in digitization of readings and assignments. Annotated sketches of thin sections on paper evolved to hybrid or digital assignments including digital photography. Case studies involving mineral resources provided opportunities to discuss social justice and inequity. Through many iterations of the course, the “best” way of teaching reflected the affective as well as cognitive conditions for that semester.