SWX8595 - Preston Tank Sewer, Weymouth, Dorset, Archaeological Monitoring of Geotechnic Pits

Wessex Archaeology was commissioned by Wessex Water to undertake an archaeological watching brief during the excavation of four geotechnic test-pits. The test-pits were excavated in advance fo the proposed construction of a new tank sewer located to the south of Preston, Dorset (centred on SY 7030 8260). The satching brief represents the continuation of an ongoing scheme of archaeological works associated with the proposed development. A previous archaeological desk-based assessment had concluded that there was a potential during the pipeline construction to discover remains associated with the Preston Roman Villa (Scheduled Monument no. DO64) which is located immediately to the north of the proposed pipeline route. The archaeological desk-based assessment was supplemented by the hand-excavation of five archaeological test pits (TP1-5) along the proposed pipeline route. These revealed a soil layer (TP1) of probable Romano-British date (AD 43 - 410), and a feature containing a quantity of worked flint (TP3), some of which was considered to be of Mesolithic date (c. 8,500-4,000 BC). The four geotechnic test-pits (TP6-9) were machine-excavated on the approximate line of the tank sewer. Although no archaeological features were identified, a quantity of worked flint was recovered from a subsoil layer within TP7, located close to the earlier TP3 which had produced a similar assemblage of material. Although broadly undiagnostic, the worked flint recovered from TP7 contained a few elements that would not be out of place within a Mesolithic assemblage, albeit with examples that are considered to be later in date (i.e. Late Neolithic/Bronze Age; 3,000 - 700 BC). In addition, a few gragments of Romano-British tile, an abraded sherd of samian pottery, and a sherd of Late Iron Age/Early Romano-British (100 BC - AD 150) pottery, were recovered from TP8, located close to the southern boundary of the Preston Roman Villa Scheduled Monument. The results of this phase of archaeological monitoring appear to support the findings of the previous investigations, and combine to suggest that there is a prehistoric flint-knapping site in the vicinity of the proposed pipeline route, potentially of an early (i.e. Mesolithic) date. In addition, the recovery of Romano-British material, particularly twoards the edge of the adjacent villa to the north, confirms the likelihood that archaeological remains associated with that villa may extend beyond the formal limit of the Scheduled area.