MID- TO LATE HOLOCENE ENVIRONMENTAL CHANGES RECORDED BY SEDIMENT FROM LAKE ERIE'S EASTERN BASIN

Understanding how Lake Erie has responded to changes in climate and hydrology in the past will improve our ability to measure current human impacts on the lake, and to predict responses in the future. Lake sediment properties can be used to reconstruct changes in paleoenvironmental conditions such as water temperature, lake level, source water, precipitation, and biologic activity, among others, and to understand the influences of major events like drainage and outlet changes. In this study, we found significant mid- to late Holocene shifts in proxy data, including upward increases in magnetic susceptibility, carbonate content, and d13C, and a decrease in grainsize. The data was taken from long sediment cores from Lake Erie's eastern basin, and was then compared with data from several previous studies. These shifts coincide in time with the erosion of the Lyell-Johnson sill, and also align roughly with local and global climate changes, which may have had a similar influence on sediment properties.