Monument record SUT 195 - Survey of the salt marsh and foreshore below Sutton Hoo

Following the discovery of man-made wooden structures and pottery on a stretch of foreshore below Sutton Hoo in 2002, a programme of archaeological work was undertaken to better understand the archaeology and dynamics of the area. As a result of this, repeat visits were made in 2003, 2005 and 2009 to monitor the rate of further erosion, the survival of known wooden structures and to record any newly exposure timbers. The grid pegs set out in 2002 to monitor sediment changes on the foreshore showed erosion of c.30mm, on average, with accretion of 10mm apparent on the surviving pegs in the northern part of the grid. A temporary layer of soft, waterlain silts was present over the foreshore at the time of both visits, making it difficult to assess the condition of previously recorded timber structures. Clearly some erosion of the foreshore had occurred as two new areas of timbers were recorded, both comprising a mix of vertical posts with horizontal infill. Remains were fragmentary, neither cluster appeared formalised and the wood was in poor condition. A vertical hazel (Corylus avellana) stake removed from wood scatter 0041 in the southern part of the survey area was radiocarbon dated to 320 AD +/- 30, the earliest date yet obtained from this site. Survey of the salt marsh edge shows continued gradual erosion and a single sherd of medieval coarseware pottery found on the foreshore suggests that pottery continues to erode out of the salt marsh (S1).

The site was visit on monthly bases over six months. Fieldwalking recovered a quantity of Roman pottery as well as medieval sherds, as well as worked and burnt flints. Monitoring of the wooden structures showed no appreciable change in their form over six months, none were any newly exposed structures observed elsewhere in the study area. Comparative surveys of the saltmarsh edge show whilst it was visibly eroding, it did not retreat a significate rate over the course of the study. Sampling columns were taken through the foreshore sediments for radiocarbon dating of wood and mud samples. Twenty sediment samples were collected from two sections. The lowest deposit showed the channel had once been freshwater, starting to become brackish around 570 BC +/-50. A second radiocarbon date of 1 AD +/- 50 came from a sample just below the present foreshore. Alder from a wood scatter pile near the high tide was radiocarbon dated to 420 AD +/- and a hazel pole from wattling on the low tide line was dated 590 AD +/- 50. Sediment samples taken from directly beneath the wattle areas suggested the wooden structures were constructed in a similar environment to that present date. Although the wooden structures were too fragmentary to be certain on their function, based on topographic and environmental evidence they are most likely to be the remains of fish traps (S2).