USING PETROGRAPHIC DATA FROM ELECTRON MICROBEAM INSTRUMENTATION IN THE CURRICULUM: DIGITAL RESOURCES CAN HELP

Electron microbeam instruments are key elements in the toolkit of modern petrographers. Any type of quantitative analysis with high spatial resolution requires complementary imaging data to reveal the significant and small-scale chemical heterogeneities that characterize many natural materials. Beyond this obvious connection between analysis and imaging however, electron microbeam instruments have powerful applications in a purely petrographic mode of use. Images created with cathodoluminescence, back-scattered electrons, and X-rays are examples of modern petrography each of which has revolutionized knowledge across a broad spectrum of the geosciences. Learning about these vital petrographic methods can take place in many contexts, including traditional courses such as “mineralogy”, “general petrology”, “geochemistry”, or “igneous, metamorphic, or sedimentary petrography”. As traditional offerings increasingly compete for space within modern curricula, however, adding expanded content to such courses is a challenge. The use of interactive digital methods is one strategy for enhancing petrographic education that can be readily applied to presentation of electron microbeam imaging as well as to conventional light microscopy. Instruction in modern petrography however is most effective if founded on the student's clear understanding of the basic chemistry and physics that underlie energy/crystal interactions.