PARENT SESSION
Poster Session 21: Paleoecology
Wednesday, August 10, 5:00 PM - 6:30 PM, Exhibit Hall 220 A-E, Level 2, Palais des congrès de Montréal

A high-resolution diatom-based Holocene paleoenvironmental reconstruction from the western Canadian Arctic.

Podritske, Brandi^*,1, Gajewski, Konrad¹, ¹ Laboratory for Paleoclimatology and Climatology, Department of Biology, Ottawa, Ontario, Canada

ABSTRACT- Relatively little is known about millennial- to centennial-scale climate variability in the Canadian Arctic. We can achieve a better understanding of climate variations on multiple scales by performing high-resolution lake sediment studies in areas where there are no paleoclimate records. A 411 cm sediment core was collected from a small lake, unofficially named KR02 (71.34°N, 113.78°W, 229 m.a.s.l.), from the Kuujjua River region of western Victoria Island, NWT, Canada. Core chronology was determined using radiocarbon dating and diatoms were evaluated at various depths throughout the core. The lowermost date was 8730 ± 60BP, corresponding to a calendar age of approximately 9700 BP. Loss-on-ignition, a measure of the carbon content of the sediment, generally increased from the early Holocene to the present and magnetic susceptibility showed an inverse trend. The loss-on-ignition curve can be divided into three distinct zones with the early and late Holocene showing greater variability than the mid-Holocene. Preliminary results show that Fragilaria sensu lato was the dominant diatom in the core. In general, the relative percent abundance of Fragilaria construens f. venter and F. pinnata were inversely related. Other important species recorded in the core include Amphora thumensis, Amphora libyca, Amphora pediculus, and Cyclotella bodanica var. lemanica.

Key words: diatoms, Canadian Arctic, Holocene, high-resolution