EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers

The closed basin lakes of Taylor Valley fluctuate in lake level, responding to the net balance of water gain and loss. Geomorphologic evidence suggests that past lake levels in Taylor Valley were once much higher than they are today. Past studies have largely targeted organic radiocarbon as a means for dating these past lake levels. However, an unconstrained radiocarbon reservoir effect in the region reduces the credibility of those data and the lake level chronologies they produce. Alternative geochronometers are therefore necessary to validify or augment the lake level records produced using organic radiocarbon. This research tests the overarching hypothesis that a multi-proxy geochronologic approach can constrain the timing of major changes in Taylor Valley lake levels. The goals of this study are to provide a coarse-scale absolute chronology for lake level fluctuation in Taylor Valley in order to test the validity of the lake level record hypothesized by the organic radiocarbon datasets, demonstrate that in situ 14C and OSL are effective means to understand the physical dynamics of ancient water bodies, and increase the current understanding of polar lacustrine and ice sheet responses to past and present climatic changes.