CHEMICAL ZONING AND TEXTURAL ANALYSIS OF A MID-OCEAN RIDGE BASALT: AN ELECTRON MICROPROBE ANALYSIS COURSE PROJECT

The Oklahoma State University Electron Microprobe course allows undergraduate students to develop independent research over a 16-week semester. The goal of this specific project was to chemically examine a mid ocean ridge basalt (MORB). The topic is ideally suited for an electron microprobe course, as it builds on subjects that students have learned in prior classes (e.g., Mineralogy, Petrology, Tectonics), while introducing technology into their learning experience. Specific topics that can be examined in more detail include: phase diagrams, chemical zoning, MORB petrographic and chemical characteristics, petrogenesis, tectonics, and structure.

Throughout the semester, backscattered electron images, both 2-D and 3-D element maps, and qualitative energy dispersive X-ray spectra were produced. The basalt contains plagioclase with saw-tooth edges and oscillatory zoning. The presence of this type of zoning indicates that the grains experienced complex changes during growth. Future classes will build upon this project and further study the oscillatory zoning patterns and elements present in this sample. The research sparked interest in understanding how chemical analyses could help determine the movement of, and ascent rates of magma throughout sub-volcanic systems.

This course and project helps to facilitate innovative new technology into the scientific education of undergraduate students. Using a MORB for a class project is an innovative approach to couple state-of-the-art technology with professor/student collaboration. This can expand a student's knowledge in areas of igneous petrology, while broadening their laboratory and research skills.