Window Sampling on land at Pescod Square, Boston, Lincolnshire

Centros Miller are undertaking the development of Pescod Square Boston. ARCUS have been appointed to act as archaeological consultants to the scheme. Prior to planning permission being granted a programme of archaeological evaluation was undertaken. This comprised a desk-based assessment (Belford and Symonds 1996) and a field evaluation (Davies et al 2002). Based upon the results of the archaeological evaluation planning permission (B/01/0440) was granted subject to conditions. An archaeological mitigation report was produced (Davies 2002). This outlined a programme of work to be undertaken to preserve the archaeology either in situ or by record. Following negotiation with Rebecca Wilcox (Boston Borough Council Archaeologist) it was determined that the sleeving on piles would extend to a depth of 5m. However, the mitigation report included a provision to reduce this depth of sleeving if the depth of archaeologically sensitive deposits could be determined by window sampling. This report describes the results of a watching brief undertaken on window sampling and outlines a simple deposit model for the northern end of the site. Over the area of the evaluation the base deposits were alluvial silts and clays. The depth at which these started varied slightly and they were also inter-bedded with peat layers in most cores. Despite the close proximity of the cores, particularly along Wide Bargate, it was difficult to relate layers between the cores; cores WS1, WS2 and WS3, only 8m apart in total, had 2, 1 and 3 peat layers, suggesting extremely localised variations in the stratigraphy. The majority of finds recovered were small pieces of ceramic building material (brick or tile). However, pottery, bone, clay pipe, slag, leather and glass were also recovered. The most interesting finds recovered were the sherds of pottery recovered from WS4, WS5 and WS6. These were examined by Dr Chris Cumberpatch. Sixteenth to eighteenth century pottery was recovered from WS6 at a depth of 1.50-1.60m below current ground surface. Unglazed medieval pottery, some of which might be early medieval, was recovered from depths of 1.72-1.82m below current ground surface in WS 5 and from 1.70m and 1.90m below current ground surface in WS4. Given the limitations of identifying deposits and recovering artefacts from window samples the fieldwork appears to have identified the depth to which archaeology extends. This would suggest that archaeology extends down to a depth of around 2.70 m from current ground surface on the Wide Bargate frontage (WS1, WS2 and WS3) and that this depth of deposits extends back about 20m from the front (WS4). However, further back from the frontage than this the archaeological deposits dip down to a greater depth, 3.4m at WS5 and 3.7m at WS6.