Northeastern Section - 49th Annual Meeting (23–25 March)

Paper No. 1
Presentation Time: 8:00 AM-12:00 PM

A 3.6 MA TEMPERATURE RECORD FROM LAKE EL’GYGYTGYN, RUSSIA BASED ON ORGANIC BIOMARKERS


HABICHT, M. Helen1, CASTAÑEDA, Isla2, BRIGHAM-GRETTE, Julie3, DE WET, Greg A.4, KEISLING, Ben1 and SALACUP, Jeffrey M.1, (1)Department of Geosciences, University of Massachusetts Amherst, 611 N. Pleasant St, Morrill Science Center II, Amherst, MA 01003, (2)Department of Geosciences, University of Massachusetts, 611 N. Pleasant St, Morrill Science Center II, Amherst, MA 01003, (3)Department of Geosciences, Univ of Massachusetts, 611 N. Pleasant St, Morrill Science Center II, Amherst, MA 01003, (4)Geosciences, Univ. of Massachusetts, 611 N. Pleasant St, Morrill Science Center, Amherst, MA 01003, mhabicht@geo.umass.edu

Lake El’gygytgyn, Chukotka, NE Russia was created by a meteorite impact ~3.6Ma and remained unglaciated since its formation. It provides the only continuous sediment record of polar climate history for the Cenozoic and comprises a composite length of 318m. Biomarker analysis of the sediment core is being used to assess continental temperature trends during the mid-Pliocene, when atmospheric CO2 concentrations are thought to have been similar to today. This study uses deuterium/hydrogen (D/H) ratios of plant leaf wax n-alkanes and the MBT/CBT proxy from branched GDGTs to reconstruct temperature patterns at 2- meter resolution throughout the entire Lake El’gygytgyn record back to 3.6 Ma. The use of these two proxies will allow for the development of an accurate and robust temperature record – the first of its kind from the terrestrial Arctic. This biomarker analysis and temperature reconstruction should identify broad scale climate intervals and trends such as warming during the Pliocene and stepped cooling through the Pleistocene.