Millennial Scale Fluctuations of Dry Valleys Lakes: Implications for Regional Climate Variability and the Interhemispheric (a)Synchrony of Climate Change

A Supplement to this award enabled similar efforts to be applied to ice-surface and short-core deposits from Lake Hoare (also in Taylor Valley), as well as to paleo-deltas at Lake Fryxell. The luminescence procedures employed included: multi-aliquot, polymineral fine-silt (IR-stimulation for feldspar signals), single-aliquot, multi-grain sand-size quartz (blue diode stimulation), and single-grain quartz (green laser stimulation).

The data set for the Collaborative award will thus include a variety of luminescence age estimates, some compared to independent age estimates (either from C-14 on carbonacious matter or known modern settings [thus of 'zero age']). The purpose of this data set from the Supplement award was to determine which of these procedures and which of the sediment fractions (each often representing a different depositional process, ergo a different daylight-exposure history, daylight exposure being the 'clock-zeroing' mechanism) would provide the most accurate age estimates for the burial time of the sediment.

The purpose of the main Collaborative award data set was to exploit the results from the Supplement experiments to obtain accurate ages of sediment burial for selected horizons within the cores. Unfortunately, several of the cores (e.g., those from Lake Vanda, most from Lake Fryxell) were disturbed during shipment from Antarctic to Reno, thus limiting the number of core samples available for dating analyses.