AN ASSESSMENT OF SPATIAL HETEROGENEITY IN SEDIMENT ACCUMULATION AND HOLOCENE SEA LEVEL RISE ALONG THE CONNECTICUT COAST

A large suite of subaqueous vibracores collected along the shallow nearshore coast of Connecticut provide insight into the spatial heterogeneity of sediment accumulation, submerged landforms, and Holocene sea level rise. Previous work has generally focused on the analysis of individual cores or transect lines at one or a few sites to reconstruct local sea level dynamics. These studies are often limited by access to large spatial datasets that would otherwise aid in contextualizing each site at a regional scale. Here, we present a selection of 5-10 vibracores that capture Holocene landscape change and the onset of sea level rise at different sites, spaced evenly across the Connecticut coast of the Long Island Sound. All cores were described according to NRCS soil description protocols and primary units were characterized by organic content, bulk density, and grain size. Select material was analyzed for radiocarbon dating. Radiocarbon dates were calibrated and for each site, age-depth models were produced using the rBacon age-depth modeling package. The age-depth models at each site are compared with published global (eustatic) and regional sea level reconstructions, where applicable. Ages span from the late Pleistocene to the last 300 years, and several distinct depositional environments, as well as hiatuses, are identified and correlated. Overall, this work examines the contribution of spatial variation to assessments of sea level dynamics across a large post-glacial estuary and discusses the implications of glacioisostasy and sediment compaction in correcting sea level rise rates determined from vibracore analyses.