THE LATE-GLACIAL SEDIMENTARY N-ALKANE AND HYDROGEN ISOTOPE RECORD OF TWO SITES IN NEW ENGLAND

The Late-glacial/Holocene boundary was a period of considerable environmental changes in the Northern Hemisphere. The Laurentide Ice Sheet (LIS) in North America was the largest ice sheet during the last glacial period. The past environmental impact of deglaciation process can be evaluated by employing a variety of paleo-ecological methods. The sedimentary n-alkane and hydrogen isotope record is a proxy for past hydrological dynamics and can indicate past atmospheric circulation patterns. In recent years, more attention has been paid to these proxies in the New England region, namely in the n-alkane and hydrogen isotope record of two sites in Adirondack Mountains and nC29 record of Twin Pond (Vermont) (Schartman et al. 2020, Stefanescu et al. 2023). These studies suggest surprisingly little change in the hydrogen isotope values of mean annual precipitation over the past 14,000 years. Here we present and compare two new sedimentary n-alkane and hydrogen isotope records from Quebec (Canada) and Vermont (USA) that help regionally expand and specify the reconstructions of the hydroclimate changes at the Late-glacial/Holocene boundary.