A Neolithic and Bronze Age Monument Complex and Its Early Medieval Reuse: Excavations at Netherfield Farm, South Petherton, Somerset, 2006
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02 Mudd:Layout 1 03/07/2013 08:49 Page 3 A Neolithic and Bronze Age Monument Complex and its Early Medieval Reuse: Excavations at Netherfield Farm, South Petherton, Somerset, 2006 andrew mudd and mark brett With contributions by Hugo Anderson-Whymark, Stuart Black, Sarah Cobain, Jonny Geber, Frances Healy, Nathalie Marini, E. R. McSloy, Elaine L. Morris, Kathryn M. Price, Sylvia Warman, Geoff Warren, Nick Watson, Keith Wilkinson and Tim P. Young An early Neolithic causewayed enclosure, a middle Neolithic long enclosure and an earlier Bronze Age open enclosure were among a group of prehistoric features discovered and examined by excavation at Netherfield Farm, South Petherton during archaeological mitigation work ahead of the construction of a natural gas pipeline between Ilchester and Barrington, Somerset, in 2006. Of particular interest were burnt deposits within the long enclosure ditches and a possible Bronze Age field system. Assemblages of pottery and flintwork contribute to the understanding of these features and a programme of radiocarbon dating has amplified the chronology of activity on the site. Evidence from a group of burnt and unburnt pits and a partial enclosure reveal the reuse of the site between the fifth and eighth centuries AD. INTRODUCTION The discovery and partial excavation of a group of prehistoric monuments at Nether - field Farm, South Petherton, in Somerset provides new information on the distribu - tion and use of monumental architecture in Neolithic and Bronze Age Britain. The group comprised an extensive spread of remains, including a causewayed enclo sure, a long enclosure and a linear arrangement of ring-ditches, and is the first of this type of complex to be found in Somerset. The small size of the causewayed enclosure and the low frequency of material found retrieved from its ditches explain its incon spicuous presence in the modern landscape. Conversely, the long enclosure contained relatively abundant charred plant remains and other finds. The nature of both these monuments makes the complex unusual in national terms since causewayed enclosures are usually the more archaeologically productive of the two. The pits and ditches on the site of Archaeol. J., 169 (2012), 3‒86 02 Mudd:Layout 1 03/07/2013 08:49 Page 4 4 excavations at netherfield farm, south petherton the causewayed enclosure returned radiocarbon dates between the fifth and eighth centuries ad and indicate its reuse during the early medieval period. This evidence conforms to a wider pattern of early medieval activity found in and around prehistoric monuments identified across the county and beyond. As elsewhere, the extent, nature and motives for this reuse are not easily determinable from the scant remains recovered. illus. 1 Site location. Scale 1:125,000 BACKGROUND Cotswold Archaeology carried out a programme of archaeological work along the route of a new gas pipeline between Ilchester (NGR ST 50952295) and Barrington (ST 37851860) in Somerset (Illus. 1) between April 2005 and September 2006. Following several stages of earlier desk-based and field survey, field evaluation took place as mitigation work along the 17 km pipeline route between April and June 2006. Significant archaeological remains were identified in nine fields. Two of these fields, Areas 47 and 48, contained archaeological features that are considered to be of national 02 Mudd:Layout 1 03/07/2013 08:49 Page 5 excavations at netherfield farm, south petherton 5 significance and are the subject of this report. The other archaeological findings mainly relate to Roman settlement and land use and are summarized elsewhere (Brett and Mudd forthcoming). The initial blanket magnetometer survey along the entire 20 m-wide pipeline ease - ment revealed a circular enclosure (later defined as a causewayed enclosure) and a long enclosure on land north of Netherfield Farm (Sites 48A and 48B: Illus. 2). Two long but relatively narrow evaluation trenches partially confirmed their form and date. However, the potential importance of the discovery led to the decision to fully define the extent of the features by magnetometer and excavate a larger area than would be affected by the pipeline. To compensate for this additional work it was agreed that the complex of features to the north (Area 47) would be examined in a watching brief, rather than by excavation. The extended magnetometer survey commenced in the southern part of the site and fully defined a small causewayed enclosure comprising a single, incomplete, circuit (Illus 2 and 3). Two partial enclosures lay immediately to the east and north- east, apparently respecting both the causewayed enclosure and each other. The block of mottled geophysical terrain further north-east contained little that was clearly identi fiable except two north-west aligned linear features which correspond tolerably well with former field boundaries of post-medieval date. To the north-east again, the exca va tions defined the full length of the long enclosure (c. 80 m) and a linear arrange- ment of ring-ditches. There were linear ditches here as well, some of which respected the ring-ditches. Other linear ditches were only faintly defined but appeared to include a small double-ditched enclosure in the northern corner of this area. The magnetometer survey suggested a further extension of this pattern of enclosures, but this was not conclusively defined within the pipeline easement. The overall results indicated a group of earlier prehistoric monuments in these fields, potentially dating from the earlier Neolithic to the Middle Bronze Age, and representing a ceremonial complex so far unique for Somerset. The trial trenching established that the archaeological features were poorly pre - served and no stratigraphy survived above the surface of the natural substrate. Accordingly, the overlying topsoil and subsoil (altogether a little over 0.4 m thick) was stripped to the top of the substrate under archaeological direction by means of a mechanical excavator using toothless grading buckets. The whole area of the cause - wayed enclosure and adjacent features was exposed in this manner (Illus. 7) together with the western end of the long enclosure, including the ditch terminals (Illus. 4). The archaeological features were planned by hand on drafting film. Fifty per cent of all discrete features were excavated following a general excavation sampling strategy. One hundred per cent excavation was adopted for pits containing burnt material. A more limited intervention, comprising the hand-excavation of six sections through the ditches, was required for the long enclosure because only its western end was affected by the course of the pipeline. This report contains edited specialist reports, full versions of which are held in archive. All radiocarbon dates are calibrated and given at 95% probability unless other- wise stated. Posterior density estimates derived from Bayesian modelling of the radio- carbon dates are expressed in italics. 02 Mudd:Layout 1 03/07/2013 08:49 Page 6 6 excavations at netherfield farm, south petherton illus. 2 Areas 47 and 48, showing geophysical survey results (Archaeological Surveys Ltd). Scale 1:4000 02 Mudd:Layout 1 03/07/2013 08:49 Page 7 excavations at netherfield farm, south petherton 7 illus. 3 Areas 47 and 48, showing abstraction and interpretation of geophysical survey results. Scale 1:4000 02 Mudd:Layout103/07/201308:49Page8 illus. 4 Plan of Site 48B, long enclosure, showing archaeological features. Scale 1:1000 02 Mudd:Layout 1 03/07/2013 08:49 Page 9 excavations at netherfield farm, south petherton 9 SITE DESCRIPTION The site lies on a gently inclined north-west-facing slope north of Netherfield Farm, approximately 500 m south-east of the hamlet of East Lambrook in the parish of South Petherton. The excavated area is situated just above the 20 m contour within 200 m of Lambrook Brook which drains into the River Parrett 1 km or so to the north-east. The geology here is a Late Pleistocene colluvial deposit which comprises a pale clay- silt with varied flint pebble inclusions deriving from the underlying Dyrham Forma- tion mudstones and sandstones (Wilkinson 2011). The poor preservation of bone here results from the sediment’s moderate acidity. The complex of Neolithic and Bronze Age features at Netherfield Farm was shown to spread over a distance of c. 600 m south-west/north-east along the east bank of the Lambrook Brook. The group comprised a causewayed enclosure, an adjacent and later U-shaped enclosure, a long enclosure about 150 m further north-east with a linear arrangement of ring-ditches close by, and a pattern of Bronze Age ditches and enclo - sures still further down the valley to the north-east. Linear magnetometer anomalies in Area 46 further north-east, examined by trial trenching, were not archaeological. neolithic Pit 48644 Lying between the two arms of the long enclosure (Illus. 4), pit 48644 was the earliest dated feature on the site. The pit was oval in shape and was 1.5 m long, 1.1 m wide and 0.6 m deep (Illus 5 and 6). Each of the three identified fills contained quantities of charcoal, dominated by oak but also containing elm, hazel/alder and cherry (Cobain this article; Tables 8 and 9). The upper fill contained a fairly substantial lump of oak charcoal, but a consideration of the form of the pit, without any recognisable post- setting or in situ burning, suggests that this does not represent the remains of an in situ post, but rather a secondary deposit of charred wood. A few crumbs of quartz- tempered pottery from the upper fill are only datable as Early to Middle Neolithic (McSloy this article), but two radiocarbon determinations on Prunus charcoal and hazelnut shell from the same context (48645) returned virtually identical dates in the range 3780–3660 cal. bc (NZA-35810, NZA-35816), making this feature substantially earlier than the long enclosure with which it appeared to be associated (Table 12; Healy, this report).