GEOARCHAEOLOGY IN THE MARSHLANDS:ARCHAEOLOGY AND THE ENVIRONMENT ON SHEPPARD’S ISLAND, DELAWARE

The Delaware Bay is the second largest estuary along the U.S. Atlantic coast and is experiencing some of the gravest effects from Sea Level Rise (SLR). Most of the estuarine shoreline is fringed by salt marshes that have been developing for the past 2,000 years but are now being lost at a rate of up to an acre/day. The trend suggests that much of the salt marsh is being covered by mudflat or converted to open water at an alarming rate, with the greatest impacts being experienced along the central Bay. Sheppard’s Island is one of many dryland hummocks within the fringing salt marshes. Existing archaeological predictive models consider these locations of low probability for archaeological recovery. However, recent archaeological survey has yielded cultural resources and indicates the potential of these underexplored landforms for expanding the archaeological record. Our paleogeographic modeling help to contextualize the archaeological resources, while also yielding indicators of past sea levels and the extent of marsh transgression. Finally, probablistic sea levels (Kopp et al 2014) applied at the decadal level through the year 2100 reveal potential future impacts. Sheppard’s Island and the marshland hummocks appear to be on the front-line for experiencing adverse effects from SLR and may serve as harbingers for the impacts of environmental changes to cultural and economic resources along the estuary.