York Historic Environment Record

An evaluation excavation consisting of five trenches carried out by North Duffield Society as part of their HLF funded investigation into the prehistory of the Vale of York south of the city of York. Trench 1: set out across a black linear anomaly in the magnetometry results. This turned out to be a deep ditch, and we hit the water table. The ditch could well be a field boundary or similar. Trench 2: this trench was sited around a big lump of slag (or possibly bog iron...when we have an answer to that, we'll let you know) that was visible on the surface by the hedge. There was also a ditch within this trench, curving slightly along its length and suggestive of a ring-ditch, although we didn't expose enough of it to draw any real conclusions about its complete shape. Several sherds of prehistoric pottery were recovered from the ditch fill, providing good dating evidence. Trench 3 and 5: on the other side of the hedge, these trenches were located over what we thought might be a building: a set of high-resistance linear anomalies in the resistance survey, which is very typically what you see over stone structures. However, first Trench 3 revealed a ditch where the wall should have been, and Trench 5 was opened up to confirm this, which it did. It may be that the better-draining silty soil of the ditches holds less moisture than the clayey natural around them, thus giving the high electrical resistance values we encountered (more water usually means lower resistance). So instead of a building, what we appear to have is a small enclosure, some 15m across. More prehistoric pottery and slag came from these trenches, including some very sizeable rimsherds! Given the amount of slag we have, it's not impossible that we have an Iron Age smelting site. Trench 4: this trench, opened on Sunday partly because we had too many people to fit in the trenches we'd already opened, presented the most exciting stuff. After Phil, Chris and Mark had hacked their way through an enormous quantity of topsoil, they discovered a clay surface bounded by some soft orange and grey materials. A little sondage down one side of the trench revealed this to be multiple layers of occupation deposits -- silty, ashy material that is laid down during human use of a structure. The clay surface turned out to be a purposefully laid layer, almost certainly a floor, actually lying over the occupation deposits, and right in the back of the sondage Phil found another, earlier clay layer underneath those deposits. So it seems we've found a prehistoric site with multiple phases of use, resulting in this multi-layered occupation material. This sort of deposit is ideal for microscopic scientific analysis when excavated carefully, and as we didn't have the resources to do that we decided to leave it in situ.