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The waters of southern England's Solent hide a drowned landscape of rich archaeological heritage, writes Garry Momber. The origins of the UK's Solent can be traced back into the Pleistocene Epoch where river systems abraded a path across the southern part of the Hampshire Basin from Dorset through to West Sussex. A sea level more than 100 metres below that which we see today exposed a European landmass where Britain was a remote peninsular separated from the continent only by waterways and lakes. As the glaciers retreated 10,000 years ago at the conclusion of the last ice age, the warming climate encouraged groups of hunters and foragers north. They exploited the resources (being richest adjacent to the watercourses) and occupied these newly accessible territories. It took another 5000 years before the lands were totally lost to the steadily rising oceans. Evolving In the western Solent, the course of the ancient river channels has not been satisfactorily detected. This is primarily due to erosion continually deepening the channel as the system is evolving. Large deposits of the early to mid-Holocene landscape do, however, fringe the waterway. They survived because they were covered and protected by alluvial silts as the waters rose. Today, they represent a rich archive of sediments and peat that contain archaeological material. This material is being exposed as the Solent continues to evolve. The loss of the resource is of great concern but it has presented the opportunity for research into the geomorphological evolution of the landscape and its relationship to archaeological material. Investigations of these exposures by the Hampshire and Wight Trust for Maritime Archaeology (HWTMA) over the past few years have been based on a programme of monitoring and sampling using the following methodology:
Surface supply Excavations were conducted in a metre wide section cut into the cliff face with a smaller trench dropped into the seabed. Surface supply diving equipment was employed for safety and enabling dive times of up to four hours. Prior to these investigations, the large oak trees exposed in the peat on the seafloor around the site were believed to form the basal organic deposit with small pockets of sand and lacustrine clays directly beneath. However, new exposures in the trench revealed a more complicated stratigraphy challenging this hypothesis. The section was planned and sampled using specially constructed monolith tins. Initial assessment suggests a number of events and adaptations to the within the complex stratigraphic sequence landscape (see diagram on previous page). The lowest exposed level contained fluvial gravel lying and yellow sand. A small cluster of burnt flints were recovered from just above this horizon. This was covered by up to 600mm of fine grey silty sand containing freshly knapped flint flakes, worked cores and organic inclusions. At the east side of the trench, timber lay directly over the fine grained sand and flint fragments. This was covered by a peaty/humic seam, dipping to the north. Central to the trench, but not exposed in section to the west, were fluvial outwash gravels. These were recorded directly above the grey silty sand. This deposit contained a possible secondary archaeological deposit of abraded Mesolithic and Upper Palaeolithic flints. The whole sequence was capped by a layer of peat dipping to the north and west which in turn was covered by Holocene alluvial silts laid down as the sea covered the landscape. Interpretation Many samples were collected which are to be subject to dating and specialist analysis. Interpretation of the results will identify the potential archaeological and geomorphological significance of the drowned landscape and lead to a reconstruction of the events that pre-empted the sea level rise that engulfed the continental shelf. Problems were realised however when trying to define the magnitude of the site and when attempting to raise material without contamination. Further problems were noted following excavation when the sandy archaeological deposit exposed in section was prone to failure. Summary The work conducted by the HWTMA has identified the potential for the resource, it has put forward methodologies for the location of archaeological sites and it has addressed research questions pertinent to the analysis of submerged cultural material. It has also acknowledged limitations in the techniques used for recovering material and techniques available for high-resolution discrimination of mineragenic materials within archaeological sites when covered by layers of Holocene deposit. It is hoped that relevant techniques employed by the subsea industrial sector, once identified, may be able to overcome these challenges. . Details - Garry Momber, Hampshire and Wight Trust for Maritime Archaeology, Room W1/95, Southampton Oceanography Centre (SOC), Southampton SO14 3ZH, UK, Tel: +44 (0)23 8059 3290, E-mail: hwtma@soc.soton.ac.uk  1) Silty grey alluvium 2) Silty alluvium with dark organic 'staining' 3) Peat deposit (in section) 4) Peat deposit covering sea bed 5) Fallen mesolithic oak trees 6) Gravel with timber inclusions and rolled worked flint 7) Fine grey sandy/silt with timber inclusions and freshly knapped flint 8) Peaty/humic deposit 9) Lower timber layer 10) Assemblage of Burnt flint 11) Course sand with flint and clastic material 12) Rolled gravel |
© 2004 Underwater World Publications Ltd.