Project Description
The student will be preparing and analyzing samples from sediment cores from Paleolake Olduvai (Tanzania) using a variety of techniques, including X-ray Diffraction (for Mineralogy) and X-Ray Fluorescence (for geochemistry) to look for mineralogical and geochemical signatures of changing lake chemistry during the Late Pleistocene in East Africa. Minerals formed within saline alkaline lakes (e.g., lake clays, zeolites, carbonates) can serve as indicators of changes in salinity and alkalinity, which can help us reconstruct changes in aridity. Element ratios, especially involving Ti, Mg, and Al, can also help.
Tasks and Responsibilites
The student will be given a set of samples already collected from the cores, covering a potentially quite interesting interval in the Pleistocene (around 1.2 million years ago) when conditions within the Olduvai paleolake are expected to shift from more humid to more arid. She will powder the samples, mount them for X-ray diffraction (XRD), analyze each using the XRD instrument, and interpret the resulting mineral data. She will also prepare a subset of the samples for X-ray Fluorescence (XRF), an involved process that involves mixing a powdered sample with 10x its mass in a Li borate flux and fusing it into a glass bead. She will run these prepared glass beads through the XRF instrument and interpret the resulting elemental data. She will use this combined dataset to look for shifts in mineralogy and composition that could indicate changes in lake conditions.
Desired Qualifications
None Listed.