FECAL STEROLS AND THE 15TH-CENTURY DEMISE OF NORSE VIKINGS IN GREENLAND

Germanic seafarers led by Erik the Red quickly established three thriving colonies in Greenland; however, by the mid-15th century, populations fell to near zero (Ledger et al., 2014). The cause is summarized succinctly by McGovern et al. (2014) as, “it got cold and they died.” Yet, this conclusion is based upon limited evidence primarily from distant ice cores. Geochemical proxies have only recently been used to correlate human occupancy with paleoenvironmental conditions (D’Anjou et al., 2012). Through analysis of organic biomarkers–alkenones, GDGTs, leaf wax deuterium isotopes (δD), and fecal sterols–the roles of temperature and precipitation will be definitively linked to the demise of the Eastern Settlement.

Radiocarbon age models suggest continuous sedimentation throughout the Norse period. Preliminary analyses have shown the presence of fecal sterols (coprostanol, 5β-campestanol, and 5β-stigmastanol) during the Norse period in at least two lakes. Branched GDGTs were found in all samples, and temperature reconstructions using the MBT/CBT paleothermometer (Castaneda and Schouten, 2011) look promising.

This novel investigation is one of the first to pair human and environmental biomarkers. Further investigation will include the use of 210Pb and 137Cs profiles, installation of on-site interval sediment traps, and GC isotope-ratio MS (GC-irMS) analysis of δD. These data will form a high-resolution record of human impact and paleotemperature to address the nature of climate change in the boom and bust of the Norse in Greenland. More broadly, it will serve as a model for future investigations into the role of climate on human migration.

Castañeda, I., Schouten, S., 2011. A review of molecular organic proxies for examining modern and ancient lacustrine environments. Quat. Sci. Rev. 30, 2851-2891.

D’Anjou et al., 2012. Climate impacts on human settlement and agricultural activities in northern Norway revealed through sediment biogeochemistry. PNAS 109, 20332-20337.

Ledger. et al., 2014. Vatnahverfi: A Green and Pleasant Land? Palaeoecological Reconstructions of Environmental and Land-use Change. J. North Atlantic, Special Issue 6, 29-46.

McGovern, T.H. 2014. Management for extinction in Norse Greenland. In: The Anthropology of Climate Change (ed. M.R. Dove), Wiley, 131-150.