North-Central Section - 39th Annual Meeting (May 19–20, 2005)

Paper No. 11
Presentation Time: 11:40 AM

MULTI-PROXY ANALYSIS OF LAKE SEDIMENTS REVEALS PALEO-ENVIRONMENTAL CHANGE IN WESTERN CONNECTICUT THROUGHOUT THE HOLOCENE


GEISS, Christoph, ABRAMS, Jeffrey L., SULTAN, Ryan S. and RODRIGUEZ, Elizabeth A., Trinity College, 300 Summit St, Hartford, CT 06106, christoph.geiss@trincoll.edu

We report the first results of an ongoing multi-proxy investigation of lake sediments from Mudge Pond (lat. 41.90deg. N, long 73.48deg. W) in western Connecticut. Our analysis of a transect of eight cores focuses on changes in sedimentological and rock-magnetic parameters to characterize the terrigenous component of the sediment and allow for the correlation between cores for lake-level reconstructions. Pollen analyses conducted on a core from the center of the basin enable us to reconstruct local changes in vegetation. We also established a record of macroscopic charcoal concentrations, which will be used to correlate variations in fire frequency and severity with changes in land-use and climate. According to our analyses late Pleistocene sediment is characterized by fine-grained sediment, rich in detrital marble and clay. Low lake levels during the early Holocene led to subaerial exposure and partial erosion of this unit and redeposition in the deepest part of the basin, while relatively stable conditions during the rest of the Holocene led to the deposition of only weakly magnetic marl. Euro-american settlement as identified through the Ambrosia-rise led to a dramatic increase in erosion rates and the deposition of strongly magnetic sediment. This change in land-use did not result in a change in fire severety as interpreted from stable deposition rates of macroscopic charcoal.