Project Description
Volcanoes and glacial ice have interacted frequently in the recent geological past in the Pacific Northwest of USA. As ice retreated since the last glacial maximum about 15,000 years ago, many glaciovolcanic edifices have been revealed in the landscape. In central Oregon, North Sister volcano show abundant evidence for eruption underneath glacial ice. The presence of natural volcanic glass in both lower pillow basalts and upper fragmental hyaloclastite deposits reflects the fire-ice interactions. We have collected numerous samples of pillows and hyaloclastite samples at North Sister volcano for study by an undergraduate student. Owing to the pressure-dependence of water and carbon dioxide solubility in magmas, the volatile content can help us determine the thickness of ice at the time of the eruption. The student will analyze doubly polished glass wafers for water and carbon dioxide by Fourier Transform Infrared spectroscopy. This helps us make paleoenvironmental reconstructions during the Pleistocene when the eruptions occurred. Moreover, the glassy samples can be examined under the microscope to document any signs of microbial life. Glaciovolcanic samples like these from North Sister can be used as analogs for habitable regions on Mars where volcano-ice interactions were common.
Tasks and Responsibilites
The undergraduate student will attend volcanology team meetings to read papers and discuss glaciovolcanism. The student will focus on larger glass samples that they have already picked and make doubly polished glass wafers for water and carbon dioxide determinations by Fourier Transform Infrared (FTIR) spectroscopy in my lab in Lapham Hall. Sample preparation of the polished wafers is labor intensive requiring care and concentration. The student will also make mounts of the picked glasses for major element study of the glasses by electron microprobe in Madison. The student will also make thin section of the rocks for microscopic study to determine if there are signs of microbial life in the samples.