The Physical Evolution of the North Avon Levels

Editor’s introduction

The construction of the new motorway links for the Second Severn Crossing and the resultant infill and developments which would come in their wake provided the opportunity for a comprehensive programme of archaeological desk-based research, auger survey, building recording, excavation, and palaeo-environmental work (The Second Severn Crossing English Approaches project). The defined area of study covered approximately 54 km2, bounded respectively to the north and east by the M4 and M5 motorways, to the south by Bristol, and to the west by the Severn Estuary. This work was completed in 1994.

An assessment report was prepared (Wessex Archaeology 1994), in which a Revised Project Design proposed a series of research aims and themes and the preparation and publication of a monograph text comprising a series of chronological chapters discussing the development of the Avon Levels landscape. There followed a lengthy period during and after the construction of the motorway links and new bridge during which the post-excavation programme was not commissioned. This happened in 2000, by which time considerable further archaeological work had taken place on both sides of the Severn Estuary and many of the most important results published (eg, Rippon 1996; Locock 1997; Locock et al. 1998; Bell et al. 2000). These more recent archaeological works and publications allowed for a more focused and critical appraisal of the research themes defined in 1994. The relative importance and information potential of some aspects of the English Approaches project could be seen to have been enhanced, and others diminished, in the light of new information and ongoing research.

The themes deemed to remain of greatest importance and potential were: 

• The characterisation and nature of later Bronze Age to Romano-British settlement and settlement patterns. 
• The characterisation and chronological development of the sedimentological sequence during the Holocene. 
• The reconstruction of the evolution of the palaeo-environment.

New proposals for publication were drawn up (Wessex Archaeology 2000), consisting of a series of papers, of which the two main ones, destined for appropriate academic journals, would deal specifically with the first of these themes on the one hand, and with the latter two on the other. The ‘archaeological’ paper was completed in 2001 and published in the Proceedings of the Prehistoric Society (Gardiner et al 2002). A suitable publication vehicle for the second, much longer, paper was identified and favourable discussions with the Editors ensued before writing commenced. The draft of the second paper was also completed in 2001. Unfortunately, in the meantime, the journal underwent an editorial review and altered its remit to the extent that the paper was no longer deemed suitable for inclusion.

The length and complexity of the paper was such that it was difficult to identify another journal that could take it in its entirety, yet it was not an attractive proposition for a monograph. Various protracted negotiations were entered into regarding suitable formats and re-arrangements of the information, including a multi-media approach to publication. In the end it was decided that the strength of the paper was in the integration of the detailed analyses with wider thematic discussions and that its integrity would be unnecessarily compromised by the various proposals to ‘disaggregate’ it that had been considered. The decision has therefore been taken to publish it here, in full, online.

The text that follows is that which was drafted in 2001. It had already been subject to external academic refereeing pending submission to the journal and the referees’ comments, and those of its major contributors, have been largely incorporated. Financial constraints have meant that no new or additional work has been undertaken and no account has been taken of any archaeological (or sedimentary) work that has been undertaken since completion of the draft, or of any more recently obtained sea-level index points. We are confident that none of this will have substantially altered the arguments and conclusions presented here though some refinements at the detailed level have certainly been achieved. The only updating that has been undertaken has been in terms of bibliographic references (several cited ‘in prep’ and ‘forthcoming’ papers have been published in the interim) and the radiocarbon dates obtained as part of the project have been recalibrated using Oxcal 4.1.

The Physical Evolution of the North Avon Levels by Wessex Archaeology