STABLE CARBON ISOTOPE ANALYSES OF SEDIMENTS CORES AND THE ORIGIN OF THE SPRAGUE RIVER MARSH, PHIPPSBURG, MAINE

The stable carbon isotope composition of salt marsh sediment cores can be used to determine shifts in the relative proportion of C4: C3 plants through time. The purpose of this study is to use stable carbon isotopes within a network of sediment cores (n=16) collected from the Sprague River Marsh, in Phippsburg Maine. The data will be plotted spatially to determine the distribution of organic matter and the isotope composition of that organic matter through time. Preliminary analyses suggest that erosion of uplands provides a significant source of sediment upon which the salt marsh grasses can colonize in the initial stages of marsh formation. The method used in this study will derive a mechanism for early marsh formation in finger marshes typical of the south central Maine coastline. Sprague River marsh is a fluvial minor finger marsh located in mid-coast Maine. Additionally, the total carbon stock of the marsh will be assessed.