THE SUBMERGED LANDSCAPE ARCHAEOLOGY NETWORK–A LANDSCAPE APPROACH TO THE INVESTIGATION OF PREHISTORIC MARINE ARCHAEOLOGY

The Submerged Landscapes Archaeological Network (SLAN) is a multidisciplinary consortium of researchers from Ireland, Northern Ireland and Newfoundland who are investigating the prehistoric environments and archaeology of drowned landscapes on the nearshore Atlantic seabed. The ultimate goal of the network is to understand how these submerged coastal environments facilitated the expansion and growth of its first peoples and how the evolving coastal landscape, marine resources and climate may have stimulated social and cultural change. Our approach to the investigation of submerged landscapes is in two distinct stages. First, we attempt to map the configuration and identify the elements of the landscape and second, we classify the archaeological potential of the landscape and focus on local site survey and testing. It is our belief that this landscape-based approach will ultimately be more successful than one that aims explicitly to survey for and excavate a discrete archaeological site. By reconstructing the landscape first we can identify areas where it has been preserved rather than eroded by marine processes and also where features preferred by past humans for settlement, such as river valleys, lake basins and sheltered lagoons, are situated. This will facilitate future underwater prospection efforts by pinpointing areas of the highest archaeological potential.

We illustrate the first stage of SLAN's approach using data from two current projects. In the Newfoundland study, early Maritime Archaic Indian sites are believed to be located on 6 to 9 ka-old shorelines that are now submerged on the seabed in 10-30 m water depth, whereas along the north coast of Ireland sea levels were lowered by 5-30 m during the earliest known Mesolithic (c.10 ka), extending the terrestrial environment onto emergent shelves. Our analysis incorporates three data sets: a computer-modeled simulation of relative sea-level (RSL) changes that predicts the depth of submerged shorelines at specified time intervals, a high resolution seafloor map, which in combination with the RSL data generates a series of reconstructed shorelines charting the prehistoric evolution of the coast; and targeted sub-bottom profiler surveys to map the geophysical signatures of palaeo ‘land-surfaces' (eg. lake basins, bogs, lagoons, beaches and terraces).