Soil and Physical Sciences Group, Lincoln University, PhD

Paleoclimate Reconstruction using Pedogenic Carbonate

The proposed research aims to derive a new terrestrial paleotemperature proxy based on the isotopic composition of pedogenic carbonate in soils of the McMurdo Dry Valleys. The paleothermometer is based on the temperature dependent fractionation of carbon isotopes during the formation of pedogenic carbonate from soil CO2. Antarctica provides a rare opportunity to apply this technique, as complications arising from soil respiration are negligible. Pedogenic carbonate will be sampled from soils on surfaces aged up to 50 ka; age control will be provided by radiocarbon dating. The paleotemperature proxy will address the issue highlighted in the science strategy (p 17): that "...there are very few high-quality direct records from the Antarctic continental margin that can corroborate inferred past climate change behaviour...".