Project Description
The research plan for the student is to focus on capping lavas at four volcanoes in northeast Iceland. Volcanoes that erupted under glacial ice in Iceland's recent geological past are called tuyas. Tuyas have characteristic flat tops formed when subaerial capping lava flows break through the glacial ice. The undergraduate will make observations of the polished thin section of the capping lavas to understand something about the crystal cargo. The undergraduate will document the minerals that constitute the observed glomeroporphyritic texture (mineral clusters) and contrast those with the minerals in the remaining matrix of the thin section. The student will then compare the mineral chemistry of the olivine, pyroxene, and plagioclase in the clusters measured by electron microprobe versus the chemical composition of those minerals in the groundmass. The student will also document any chemical zoning in the minerals of the capping lavas to evaluate evidence for magma recharge events. Finally, the undergraduate research will seek to document the chemical composition of the capping lavas using x-ray fluorescence (XRF). The student will compare the major and select trace element chemistry of the capping lavas to the chemistry of the underlying glaciovolcanic deposits.
Tasks and Responsibilites
The student will learn safe laboratory techniques in the rock aw room and for sample preparation to use the x-ray fluorescence instrument. The student will meet weekly with the Volcanology Research Group to read and discuss relevant volcanology journal papers to provide context to the research project. The student will use the rock saw to cut small pieces from capping lava samples for polished thin section preparation. The student will use the petrographic microscope to document the minerals and textures in the polished thin sections. The undergraduate researcher will take photomicrographs of the minerals and textures in the thin sections. Moreover, the student will mark the thin sections with a fine sharpie to delineate mineral groups to analyze by electron microprobe. The student will also powder the four capping lava samples in preparation for the x-ray fluorescence measurements. The undergraduate researcher will determine the loss on ignition value for the powders to indicate the volatile content of the samples. They will also fuse glass pellets from the four powders in preparation for major and select trace element content measurements on the XRF instrument. The student will make a poster presentation for the UWM Undergraduate Research Symposium