South Cadbury Environs Project
The interpretation of the gradiometry has been done using Network Analysis in GIS and, as here, by eye guided by the results of test pitting and excavation. Two case studies are presented below. The first revisits the Sigwells pilot study, where extensive excavations have necessitated profound revision of initial hypotheses (Tabor and Johnson) and some of those derived from Network Analysis (Lock and Pouncett 2007a; 2007b; Pouncett and Lock 2008), see the methodology section.
Since the project's foundation the 18 ha area of plateau at Sigwells has been its laboratory. It was here that local amateurs did the first fieldwalking, gradiometry, resistivity, shovel and test pitting and excavations. The linearity of the geophysical anomalies made it ideal for developing hypotheses about the significance of orientation in system recognition and phasing, whilst it's thin, light soils suit rapid excavation.
Early Bronze Age features
The three roughly parallel linear ditches share their orientation with a modern farm track further north, which seems likely to have its origin as part of the system. The initial view that this was a Romano-British system was confounded by the discovery that the northernmost linear was cut by a barrow ditch, whilst the southern one was cut by a Middle Bronze Age enclosure. Two arcs to the south and one to the north are ditches of extant barrows.
Middle Bronze Age features
The enclosure to the east of the south linear clearly respected it. Excavation suggests that it remained in use as the enclosure's north ditch was integrated into it, remaining so for a period after the backfilling of the enclosure’s other three sides. There is no evidence that the other linears remained in use, although a keyhole trench produced Black Burnished ware from the upper silts of the middle linear. The enclosure itself was dated by Deverel Rimbury style globular urn sherds and casting mould fragments for Wilburton style metal work.
Middle Iron Age features
The best dating evidence for the system came from the arterial double ditch track oriented east – west before it turns towards the north west. Both ditches produced Middle Iron Age, shell-tempered pottery in the area where they bisected the Middle Bronze Age enclosure. However the ditches had been recut and the orientation is shared with systems around Cadbury Castle and at Woolston which are considered to be Later Bronze Age and it is reasonable to suggest that this system had its inception during that phase.
The pit group to the north west is arranged along a track and ditch which appears to have been oriented on the northernmost barrow, which also provided the baseline for the first phase of the near square enclosure at the west end. The earliest pits appear to post date the enclosure. The group is one of three on spurs overlooking Cadbury Castle, the others being at Woolston (see below) and Hicknoll Slait.
Late Iron Age features
Without further exploratory excavation or test pitting it is not possible to tell which parts of the system remained in use or fell into disuse, or which components represent expansion or subdivision. The best understood area is the north west enclosure, where the east ditch was extended southwards and the east terminal of the south ditch entrance was rendered more open. The pit group expanded greatly during the decades leading up to the Roman invasion.
First century AD features
There was an abrupt change to the boundary patterns in the landscape at around the middle of the first century AD. A banked track effectively by-passes the north-west enclosure and a group of paddock-like enclosures develop slanting slightly across the line of the southern Early Bronze Age linear, a boundary which may still have been traceable.
Further south a near rectangular enclosure is an entirely new element. The pottery from the early fills of the enclosure and internal ditches is broadly contemporary with the late material from the latest phase of the north-west enclosure and pits. It had a causewayed entrance on the south side, apparently along the line of an earlier track which provided a route from the plateau to the valley to the north. The upper ditch fills included Severn Valley wares which also occurred in burnt pit deposits within the enclosure.
Middle Romano-British phase 1 features
Middle Romano-British phase 2 features
The chronological relationship between the putative first Middle Romano-British phase and the second is problematic. The orientation of the first phase is similar to that of a boundary ditch immediately to the east of the south enclosure and its distinction from the second phase is based on a sharp change in orientation and the apparent relationship with earlier phases. Both phases remain weak without further excavation.
Late Romano-British features
The Latest Romano-British phase, for which dating was obtained by excavation of the north north east to south south west linear to the east, appears to represent a formalising of the second Middle Romano-British phase. Two stone walled buildings from this phase have been excavated by Peter Leach and gradiometry suggests at least one more building exists. Further analysis is required to integrate the information and then amplify the map.
There is no evidence for bounding of the landscape after the Roman period prior to modern enclosure, although it seems unlikely that the dry but tractable plateau soils were entirely overlooked.