A MULTI-PROXY INVESTIGATION OF HOLOCENE ENVIRONMENTAL VARIABILITY IN CENTRAL NEW YORK

This study presents a multi-proxy approach to investigate environmental variability during the Holocene in central New York . A ~13.5 m sediment core collected from the Catharine Creek wetland located south of Watkins Glen, NY at the southern tip of Seneca Lake was analyzed for total nitrogen (% TN), total organic carbon (% TOC), C/N ratios, and δ¹³C of bulk organic matter. There is little change in TOC with the exception of an organic rich interval (~20 %TOC) between 5.5 and 4.3 m. Between 13.5 and 6 m, the C/N ratios decrease gradually upcore, from ~40 to ~10 – 20. That change is paralleled by an increase in δ¹³C values from ~ -27‰ to ~ -24‰. Between 6-5.5m, δ¹³C becomes significantly more negative (~ -30‰). The δ¹³C increases (to -26‰) upcore. High C/N values at the bottom of the core are consistent with input of land plants. The shift in C/N values from 10 – 20 represents a mixed signal of both algal and land plant derived organic matter. Throughout the Holocene, there has been a steady shift from negative δ¹³C values to more positive values, which is consistent with an increase in the abundance of C4 plants in the watershed. Shifts in C/N over the length of the core may provide evidence for changes in lake level.