USING THE SCANNING ELECTRON MICROSCOPE FOR DISCOVERY BASED LEARNING IN UNDERGRADUATE COURSES

Laboratory exercises incorporating a variable-pressure (VP) SEM can encourage undergraduate students to explore geologic concepts and methods. Through an NSF-CCLI grant (DUE #9951390), a VP-SEM with Energy Dispersive Spectrometer (EDS) has been used in introductory-, mineralogy-, and petrology- courses, and in undergraduate independent study projects. Student response has been overwhelmingly positive. The undergraduate students, regardless of course level, tend to master the basics of operating the SEM quickly. After a half hour (or less), most students feel confident enough to take control of the SEM and use it to answer questions, or test ideas.

The laboratory exercises developed allow students freedom to pursue their own ideas and interests within the framework of a broader geologic question or concept. For example, in an introductory geology course, groups of four students design questions that can be answered using the SEM and sand they collect from beach profiles, such as "do mineral proportions change along the width of the beach?" and "does grain morphology change along the profile?" In addition to answering their questions, they also learn, among other things, about mineral compositions, sampling biases, and the principles of electron microscopy. The enthusiasm of the students and their comments when using the SEM show that they are actively engaged and learning geology.