Iron Age settlement and cremation, Passingford Bridge Bund and Widening and Flood Alleviation Area, M25002.09, Junctions 27 to 30 of the M25 (EHER 80929)

An Iron Age settlement, evidenced by the remains of roundhouses, a field system, and a cremation burial.

2008 to 2011. SMS. The ring ditch was situated on the floodplain in the southern part of the excavation area where the River Roding arcs around from a north-south course to an east-west flow. Given its stratigraphic relationship with two rows of postholes, the ring-ditch is at least of middle Iron Age date or earlier. An assemblage of worked flint was recovered from the feature, but it included a blade component suggestive of a late Mesolithic, and therefore residual, date. The ring ditch was annular in form, with an internal diameter of around 7.8m. The ditch measured 1m in width and 0.10m-0.16m in depth, and had a flat base. It was filled with pale grey silt. No central burial, or indeed any other contemporary feature, was identified within the ring ditch, and it is not certain whether the feature represents a plough-levelled barrow or another type of ritual monument. Other features assigned to this phase were widely dispersed and most were small, representing either postholes or small pits. Some 30 sherds of late Bronze Age to early Iron Age pottery were recovered. A possible four-post structure, defined by postholes, was uncovered near the northern part of the excavation area. The postholes formed a rectangle. Fragments of a shouldered jar and carinated bowl suggest a late Bronze Age or early Iron Age date for deposition. The remains of a shallow, NW-SE aligned ditch, survived in the far south of the site. The fill was dated by six sherds of flint tempered pottery dated broadly to the Bronze Age or earlier Iron Age. Its very shallow profile raises the possibility that related stretches of ditch belonging to a wider system of prehistoric land division had not survived. A series of ditches immediately west of the settlement defined field boundaries or large enclosures. Several coherent groups of postholes were noted among the mass of (largely undated) postholes recorded within the field system. A grave was situated to the west of ring ditch. The cut was oval in plan its lower fill contained charcoal and burnt bone. Above this were the broken remains of a cremation urn, a butt-beaker in grog-tempered ware, and an accessory vessel, a fine red-surfaced grog tempered ware beaker dating to the first half of the 1st century AD. The placement of the cremation burial close to the ring ditch suggests that the monument was still visible at this time. <1> - <4>