Archaeological Discoveries along the Farningham to Hadlow Gas Pipeline, Kent This report has been downloaded from www.kentarchaeology.org.uk the website of the Kent Archaeological Society (Registered Charity 223382), Maidstone Museum and Bentlif Art Gallery, St Faith's St, Maidstone, Kent ME14 1LH, England. The copyright owner has placed the report on the site for download for personal or academic use. Any other use must be cleared with the copyright owner. Route of pipeline with sites marked – page 100 Main sites:- Mesolithic – South of New Ash Green (MT01) – page 5 Late Iron Age/early Romano-British - East of Ightham Court (Plot 12/08) – page 28 Romano-British – South of New Ash Green (MT01, Plots 4/01–3) – page 42 Roman Villa, Fairlawne Park, Plaxtol (Plots 16/01 and 17/02) – page 72 Anglo-Saxon cemetery, Pilgrim’s Way (MT02, Plot 8/03) – page 94 May 2015 Wessex Archaeology, Portway House, Old Sarum Park, Salisbury SP4 6EB tel: 01722 326867 fax: 01722 337562 email: [email protected] www.wessexarch.co.uk Archaeological Discoveries along the Farningham to Hadlow Gas Pipeline, Kent by Andrew B. Powell with contributions from Phil Andrews, Catherine Barnett, Kayt Marter Brown, Nicholas Cooke, Jessica M. Grimm, Phil Harding, Jacqueline I. McKinley, Lorraine Mepham and Chris J. Stevens and illustrations by Rob Goller and S.E. James Introduction Middle–Late Bronze Age cremation burials, Late Iron Age and Romano-British enclosures, a probable Romano-British villa, and an early Anglo-Saxon cemetery were among the discoveries made during mitigation works (targeted strip-map-and-record excavation and watching brief) undertaken in 2008–9 prior to the laying of the Farningham to Hadlow Natural Gas Pipeline, in Kent (Wessex Archaeology 2011a) (Fig. 1). The 22 km pipeline route runs between Horton Wood in Fawkham (NGR 557870 562350), 3 km east of Farningham, to the north, and the Tonbridge Road gasworks (NGR 562350 149300), 1 km west of Hadlow, to the south. The northern end lies within the North Downs, and the southern end within the Weald, and between them the pipeline crosses Upper, Middle and Lower Chalk, Gault/Upper Greensand, Lower Greensand and Wealden Clay (BGS sheets 287 (Sevenoaks) and 271 (Dartford). The drift geology along the route includes alluvium, gravel terrace deposits, head deposits and clay-with-flints. The route crosses mainly gently undulating ground, although the southern edge of the Upper Chalk is marked by a steep, south-facing escarpment at Exedown near Wrotham, between the M20 and M26 motorways, and there are further minor scarp slopes to the south associated with the Folkestone Beds and Hythe Beds. The pipeline route had previously been subject to desk-based assessment, walk-over survey and fieldwalking (RSK 2008a), and geophysical survey (Bartlett-Clark Consultancy 2007), the combined results of which indicated a number of areas of high archaeological potential. These areas were subject to trial trench evaluation (Wessex Archaeology 2008), the results of which led to the identification of five mitigation areas which were subject to strip- map-and-record excavation (Table 1). Of these, only the sites at New Ash Green (MT01) and Pilgrim’s Way, Wrotham (MT02) produced significant archaeological remains. 2 The results at New Ash Green did not match the site’s anticipated potential; instead it produced an assemblage of Mesolithic flints, and contained a complex of Romano-British features, including enclosure and other ditches, pits and a crop-dryer, as well as evidence of Anglo-Saxon activity. The site at Pilgrim’s Way contained a section of possible trackway and an early Anglo-Saxon inhumation cemetery; as the cemetery is being published in detail in a separate paper (Stoodley 2015) only a summary description of it is given in this paper. The only other feature recorded from the remaining mitigations sites was a modern hearth (not further discussed) in Golden Stable Wood (MT04). The excavations were undertaken in accordance with the standards set out in a Written Scheme of Investigation (WSI) (WA 2009). Table 1 The mitigation areas Area Plots Name Area Potential Archaeology MT01 4/01–3 New Ash Green 7.6 ha Medieval manor Mesolithic flint assemblage; Late Iron Age–Romano-British enclosure ditches and associated features; Anglo-Saxon activity MT02 8/03 Pilgrim’s Way, 11.1 ha Remains associated with Possible trackway; Anglo-Saxon Wrotham Pilgrim’s Way ancient cemetery trackway MT03 11/02–03 Kemsing Road 1.9 ha Iron ore and slag suggesting - industrial activity MT04 19/13 Golden Stable 3.1 ha Activity represented by Modern hearth Wood varied groups of finds MT05 19/15 High House 0.7 ha Record of post-medieval - Lane, Pittswood ‘High House’ The watching brief was conducted during topsoil and subsoil stripping along the whole pipeline route, within a working area generally 45 m wide, as well as in areas identified for off-easement access groundworks. Where archaeological remains were identified, access to investigate them was agreed, and sample excavation and recording was carried out in accordance with a separate WSI (RSK Environment Ltd 2008b). Archaeological features were revealed in 15 plots (Table 2). These include three groups of features, which are described in detail below. The first comprised the six Middle Bronze Age unurned cremation burials and three other cremation-related features (distributed over 1.9 km, in four plots west of Wrotham and Borough Green); the second consisted of a Late Iron Age–Romano-British enclosure and associated features (east of Ightham Court, west of Borough Green); and the third was a Romano-British stone (possibly villa) building with associated features (in Fairlawne Park, Plaxtol). 3 Table 2 Archaeological features and selected finds recorded during the watching brief, by plot (those in bold are described in detail in this report) Plot (site name) Archaeology 0/00 Post-medieval boundary ditch 2/03 Post-medieval boundary ditch 3/03 Two Romano-British boundary/enclosure ditches 3/08 Small later prehistoric pit 5/04 Undated post-hole 10/01 Two Middle Bronze Age possible unurned cremation burials; nine pits of Middle Bronze Age to Iron Age date, and undated features 11/01 Middle Bronze Age unurned cremation burial; two residual 4th century AD Roman coins; two pits, one containing Anglo-Saxon pottery, one undated; post-medieval quarry pit 11/02 One Middle Bronze Age unurned cremation burial, and three other cremation related features (two of them also possibly burial) 12/07 Middle Bronze Age unurned cremation burial 12/08 Late Bronze Age pits; Late Iron Age–Romano-British enclosure and associated (East of Ightham Court) features; Anglo-Saxon ditch; modern trackway 16/01 Romano-British villa and associated features; two copper alloy tokens – one post- (Fairlawne Park, Plaxtol) medieval, the other for 1½d inscribed Vinson Ruxley (19th–early 20th century) 17/02 Romano-British pit, gully and ditch; undated pit 18/01 Modern pits 19/13 Modern hearth; copper alloy halfpenny of George II struck 1729–39, and three 18th or early 19th century copper alloy tokens 20/02 Undated ditch Early Prehistoric Flintwork by Phil Harding Palaeolithic Following recognition in the desk-based assessment (RSK 2008a) of at least a moderate potential for Palaeolithic flints at several locations along the pipeline route, a walk-over survey was undertaken of the stripped easement, followed by targeted test-pitting, designed to locate and sample for Palaeolithic material (Wenban-Smith 2010). Although no significant Palaeolithic remains were identified, the work produced a scraper in a rolled and stained condition (Object Number (ON) 119) and a core tool thinning flake (ON 120), both from Plot 13/7, and a large slightly stained flake from Plot 13/5. These plots fall within a small outcrop of ‘head’ gravel (BGS sheet 287, Sevenoaks), immediately east of Ightham. This deposit coincides with ‘Highfield’, where in the late 19th century a local collector and tradesman from Ightham, Benjamin Harrison, found five Palaeolithic artefacts (Wessex Archaeology 1993, NWK 6 No. 26). The three additional pieces confirm that Palaeolithic material is present, probably in some quantity, in the area. 4 Mesolithic – New Ash Green (MT01) Site description This mitigation site, measuring 270 m east–west by up to 35 m wide, centred on NGR 560200 164690, lay south of New Ash Green, occupying a plateau on the North Downs at 145 m aOD, the ground sloping slightly to the north-east. The underlying geology is Upper Chalk, capped with clay-with-flints. Crossing the centre of the site was a broad band, 11–13 m wide, of pale greyish brown silt loam (6342) quite distinct from the surrounding reddish brown silty clay found across most of the rest of the site (Pl. 1; Fig. 9, below). The formation of this deposit, however, was not securely established. When cut through by the pipeline trench it appeared to fill a wide depression over 2 m deep with a concave profile, and was interpreted as a coombe. The location and orientation of the feature may be reflected in the slightly in-turned line of the 145 m aOD contour, and it was subsequently followed by historic field boundaries and trackways; a series of parallel ditches (below) were recorded cutting, or on the edge of the layer, and the 1885–94 OS map shows a field boundary and two parallel trackways at this location. An alternative view is that the localised and linear nature of the layer 6342 may be related to variable soil processes caused by rooting action, related the long-term presence of boundaries and trackways at this location; the soil’s pale colour suggests that it is heavily gleyed, and the band of dark reddish soil at its base could represent iron pan formation, rather than the base of a coombe.