Chapter 11: Concluding comments by Frank Meddens, Stuart Foreman, Martin Bates and Damian Goodburn Physical limitations of the investigation deposits and the often ephemeral character of Managing impacts to archaeological deposits within archaeology in alluvial environments (such as a busy urban environment, alongside a major road prehistoric waterlogged wooden structures). construction project, presented numerous logistical A third limiting factor was the physical difficulty challenges, which were addressed by the road in accessing some of the deeper deposit sequences. engineers through ingenious and innovative ways. The most significant waterlogged archaeological For instance, the preservation of the important deposits were found along the margins of Neolithic site identified by evaluation trenching at palaeochannels, buried beneath variable depths of Woolwich Manor Way was achieved by using light - alluvium and made ground. The project lies on the weight polystyrene fill in the road embankment periphery of Greater London, in an area which was construction, thus substantially reducing the predominantly undeveloped marshland and frequency of concrete piles required to support the agricultural land until the latter part of the 19th structure. The nature of the working environment century. Nevertheless deep modern made ground meant that investigations were for the most part was a significant obstacle in some areas (where limited to relatively small windows where there was covered by the existing A13 road embankment, for a demonstrable below ground impact from construc - example). The engineering efforts required to reach tion activity. This can be frustrating for archaeolo - the archaeology in these cases meant that the gists who naturally wish to explore the full extent of archaeological work was both costly and poten - a site or feature, but is a necessary constraint on tially hazardous. The deposit sequences were not developer-funded archaeology. In most cases this universally deep however; in areas where the should mean that the unexcavated portions of those terrace gravels lay very close to the present ground sites are preserved in situ and available for future surface, the width of the new road was stripped of investigation should the opportunity or need arise. topsoil to expose quite extensive sections of the The important Neolithic site at Woolwich Manor terrace surface, in ground conditions comparable in Way, for example, was briefly glimpsed in an evalu - most respects with investigations in rural dry land ation trench and subsequently preserved for environments. The least effective interventions posterity. On the A13 project some of the key excava - proved to be the Watching Brief work. This can be tion areas were defined by the extents of flyover explained both by the inevitable constraints on abutments, which were very small areas indeed, access and visibility, and the nature of the alluvial comparable in size with evaluation trenches. The deposits, in which it was often difficult to recognise most extensive deep investigation was the coffer features even when conditions were ideal. The dam excavation at Prince Regent Lane (Freemasons difficulties of creating a coherent archaeological Road Underpass) in which a substantial Bronze Age record under general Watching Brief conditions are piled structure was found. The extent of the well-known. cofferdam was largely dictated by the plan of the new underpass (although informed by evaluation trenching results). Contribution of the archaeological data to The scope of investigation was also limited to regional research areas where reasonable prospects existed for intact In spite of the practical limitations the particular archaeological deposits. Disturbance caused by topographical niche occupied by the A13 corridor, construction of the existing A13 and the extent of skirting the northern edge of the Thames flood - 20th century development on either side of the road plain, offered valuable insights from an archaeolog - meant that these areas often lay in narrow strips of ical and palaeoenvironmental point of view, which surviving intact deposits, flanked on either side by have fully repaid the time, money and effort truncated, disturbed or inaccessible deposits. The invested in the archaeological work. The extensive relatively undisturbed areas were identified initially presence of waterlogged sediment sequences on the basis of desk-based studies and geotechnical offered exceptional potential for the recovery of investigations, and then refined by excavating organic materials of various periods in stratified archaeological test pits and trenches during the alluvial and archaeological deposit sequences. The Phase I and II evaluation. Geophysical survey formal excavation areas and evaluation trenches, methods were not a viable option due the disturbed taken together, provide a rare series of compara - nature of the ground, the depth of overlying tively large scale investigations for the Lower 147 Landscape and Prehistory of the East London Wetlands Thames in the London region, linked by a common Europe, which have yet to be satisfactorily resolved project design and geoarchaeological research (Brown 2008, 1-18). framework. The archaeological discoveries range from the Mesolithic through to the post-medieval period, Prehistoric archaeology in the Lower Thames although material from the 2nd millennium BC was floodplain most commonly encountered, in the form of timber Until the explosion of development-led archaeology structures and in particular trackways. This volume in the 1990s, knowledge of prehistoric human therefore marks an outstanding contribution to our activity in the floodplain of the Lower Thames and understanding of the prehistory of the Lower its tributaries in the London area was limited, Thames area, particularly the Bronze Age. Together comprising occasional tantalising glimpses, such as with other recent large scale investigations within the discovery of significant quantities of metalwork, the Thames Floodplain in London, such as High mostly weaponry from the river itself, and Speed 1 (formerly the Channel Tunnel Rail Link), occasional other finds such as the Dagenham idol the Jubilee Line Extension and the Lea Valley unearthed in 1922 (Coles 1990, 326). In addition Mapping Project, the A13 investigations have there were references to wooden structures, inter - helped to clarify the sequence of inundation of the preted as crannogs or pile dwellings of uncertain Thames floodplain caused by sea-level rises during date which had been found in the later 19th century the Holocene, shedding particular light on the on the River Lea, during the excavations of the reactions of Bronze Age communities to these Maynard (Smith 1907), Warwick (Needham and landscape changes. The data is most immediately Longley 1980), Banbury and William Girling reser - relevant to the narrow but important topographical voirs. The extent and nature of the peat beds found zone occupied by the A13 corridor, at the interface in the floodplain alluvium had been remarked upon between the marshland occupying the valley floor at least as early as 1721 by John Perry in his account and the gravel terrace to the north. However it also of the stopping of the Dagenham Breach. In this contributes to discussions of contemporary cultural work Perry not only refers to the extensive presence landscape changes beyond the floodplain. As of brushwood in the peats, he also mentions observed throughout the region, there is a widespread finds of hazelnuts and yew trees and widespread change, between the Neolithic and the occasional finds of deer antlers in these deposits. He middle Bronze Age (broadly the late 3rd and early also describes the basic sequence of clays overlying 2nd millennium BC) from a landscape focused on peats, which in turn lay on top of blue clays over dispersed ceremonial monuments to an agricultural gravels and sand (Perry 1721). landscape, which in some areas is characterised by The A13 project has contributed some new data a formally delineated environment comprising co- to add to models of Mesolithic and Neolithic axial field-systems associated with stock manage - landscape evolution in the Lower Thames Valley, ment and pastoralism (Pryor 1998; Yates 2001). The but has produced relatively limited archaeological different types of archaeological data from the evidence from these periods. Other recent projects Thames floodplain provide a complementary view in the region, such as High Speed 1, have been more of this phase of settlement transformation. forthcoming in this respect (Bates and Stafford forthcoming). Nevertheless the identification of elements of a buried Neolithic landscape, including Regional sea-level and climate studies artefacts and components of carbonised wood in a This volume also presents multi-proxy palaeoenvi - varied range of woods, charred hazelnut shells and ronmental evidence from a series of radiocarbon the cereal crop remains at Woolwich Manor Way dated sediment sequences from the margins of the offer rare glimpses of Mesolithic and Neolithic Thames floodplain. Apart from the important infor - human activity within the floodplain. When set mation that these provide for the landscape context alongside other contemporary evidence in the of the associated prehistoric archaeological finds vicinity (summarised in Chapters 1 and 9) it is clear (discussed in detail in this volume) these represent that the A13 Neolithic finds contribute significantly valuable additions