Tottenham IKEA Extension Edmonton London

Tottenham IKEA Extension

Edmonton London

Archaeological Evaluation

for IKEA Properties Investment Limited

CA Project: 661041

CA Report: 18222

May 2018

Tottenham IKEA Extension Edmonton London

Archaeological Evaluation

CA Project: 661041 CA Report: 18222

Document Control Grid Revision Date Author Checked by Status Reasons for Approved revision by A 20/04/18 RSB PB Draft Quality Assurance SRJ

This report is confidential to the client. Cotswold Archaeology accepts no responsibility or liability to any third party to whom this report, or any part of it, is made known. Any such party relies upon this report entirely at their own risk. No part of this report may be reproduced by any means without permission.

CONTENTS

SUMMARY ...... 2

1. INTRODUCTION ...... 4

2. ARCHAEOLOGICAL BACKGROUND ...... 5

3. AIMS AND OBJECTIVES ...... 10

4. METHODOLOGY ...... 11

5. RESULTS (FIGS 2-11) ...... 12

6. DISCUSSION ...... 14

7. CONCLUSION ...... 15

8. CA PROJECT TEAM ...... 15

9. REFERENCES ...... 16

APPENDIX A: CONTEXT DESCRIPTIONS ...... 19 APPENDIX B: LEVELS OF PRINCIPAL DEPOSITS AND STRUCTURES ...... 21 APPENDIX C: OASIS REPORT FORM ...... 22

LIST OF ILLUSTRATIONS Fig. 1 Site location plan (1:25,000) Fig. 2 Trench location plan (1:750) Fig. 3 MOLA geological model of site (1:10,000) Fig. 4 MOLA borehole transects Fig. 5 The site, looking east (photograph) Fig. 6 Trench 1, looking south (photograph) Fig. 7 Trench 2, looking west (photograph) Fig. 8 East end of Trench 2, looking south (photograph) Fig. 9 Gully 306: section and photograph (1:20) Fig. 10 Trench 4, looking north (photograph) Fig. 11 East end of Trench 5, looking south (photograph)

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SUMMARY

Project Name: Tottenham IKEA Extension Location: Edmonton, London NGR: 535245 191749 Type: Evaluation Date: 9 to 17 April 2018 Planning Reference: London Borough of Enfield Council ref: 17/04017/CND Location of Archive: To be deposited with London Archaeological Archive and Research Centre Site Code: GRL 18

An archaeological evaluation was undertaken by Cotswold Archaeology in April 2018 of land off Glover Drive, Edmonton, London Borough of Enfield. The evaluation comprised the excavation of five evaluation trenches to a depth of between 1.5m and 2m below the present ground surface (bpgs).

Geoarchaeological interest in the site derives from its location within the Lea Valley, within an area which is on the interface between the River Lea inner and its wider floodplains. Archaeological interest is derived from the discovery within the site of 120 pieces of struck flint recovered from an alluvial deposit, some of which are attributable to the Mesolithic period, as well as the discovery of an early medieval pile dwelling or crannog located to the immediate east of the site.

Pleistocene river terrace gravels were recorded at between 1.4m and 2m bpgs, at the base of the exposed sequence across the site. These were overlain in the north of the site by brickearth deposits. Comparable deposits had previously been recorded during trial pit evaluation of the site, which represented Devensian period brickearth deposits of Enfield silts, dating from c. 17,000 BP.

Significant fine-grained alluvial/fluvial deposits were also recorded across the site overlying both the river terrace gravels and, where present, the brickearth. The top of this alluvium was encountered at an average depth of 1.17m bpgs. These fine grained alluvial deposits represent Late Pleistocene/Early Holocene development of the Lea Valley flood plain.

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Cutting the top of the alluvium within Trench 3 was an undated, east/west orientated feature, most likely representing a natural erosion gully.

The geological sequence in each trench was overlain by made ground deposited during the 19th and 20th centuries and capped by modern external surfaces of concrete or tarmac.

Based on the findings of the evaluation, which did not identify any significant archaeological finds, features, deposits or geoarchaeological sequences, it is recommended that no further archaeological work is required in relation to London Borough of Enfield Council Planning Reference 17/04017/CND.

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1. INTRODUCTION

1.1 In April 2018, Cotswold Archaeology (CA) carried out an archaeological evaluation of land off Glover Drive, Edmonton, London Borough of Enfield (centred at NGR: 535245 191749; Fig. 1). The evaluation was commissioned by IKEA Properties Investment Limited.

1.2 Planning permission for the partial redevelopment of the site to comprise an extension to the west of the existing Ikea building, in order to provide 3,929m2 of additional floor space, with undercroft car parking, together with an extension to the existing mezzanine, to provide 1,183m2 of additional floor space, has been granted by the London Borough of Enfield Council (LBEC; the local planning authority), conditional on a programme of archaeological work (ref. no. 17/04017/CND).

1.3 The scope of the archaeological works, which comprised the excavation of five trenches, was defined during discussions between CA and Sandy Kidd, Principal Archaeology Advisor, Greater London Archaeology Advisory Service (PAAGLAAS; the archaeological advisors to LBEC).

1.4 The evaluation was carried out in accordance with a detailed Written Scheme of Investigation (WSI) produced by CA (2018) and approved by Sandy Kidd. The fieldwork also followed Standard and guidance: Archaeological field evaluation (CIfA 2014). It was monitored by Sandy Kidd, including a site visit on 13 April 2018.

The site 1.5 The proposed development site is approximately 0.6ha in area, situated within an area of dense 20th-century industrial development c. 500m west of the River Lea and c. 180m west of the Pymmes Brook, a tributary of the River Lea. It comprises an area of tarmac and concrete hard standing, bounded by Glover Drive to the north, an Ikea store to the east, car parking associated with the Ikea store to the south and Angel Edmonton Road to the west (Fig. 2). The site lies within the wider floodplain of the Lea Valley at a height of c. 9.6m above Ordnance Datum (aOD).

1.6 The underlying bedrock geology of the area is mapped as London Clay Formation sedimentary bedrock, of the Palaeogene period (BGS 2018). This is overlain by Pleistocene glacial sands and gravel river terraces of the River Thames and its

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tributaries. The site lies within the modern floodplain of the River Lea, which overlies Lea Valley Gravels. Within these gravels are areas of known potential for sealed deposits of Lea Valley Arctic Beds, seams of organic material rich in seeds, foliage and animal remains preserved at the interfaces of the river terraces of the Thames and its tributaries. These deposits provide key evidence of the climate, flora and fauna of the Lea Valley during the Pleistocene periods (c. 2,500,000 – 12,000 years Before Present (BP)).

2. ARCHAEOLOGICAL BACKGROUND

2.1 The archaeological and historical background of the site has been presented in a heritage desk-based assessment (CA 2017) and investigated in a previous archaeological evaluation (MoLAS 1996b).

Deposit Modelling 2.2 An archaeological evaluation undertaken within the Ikea Lorry Park in 1996 (discussed in more detail in Section 2.8-2.10 below) used the south facing sections of the trenches to produce a schematic section across the evaluation site, which includes the current development site. This is reproduced within Figure 3 (transect A-A), and shows a decline in the river terrace gravels from east to west, which is in contrast with the results of the adjacent site which suggested the gravels descended eastwards towards the River Lea valley. The contrast may imply the existence of an area of high ground within the site.

2.3 As part of the Lea Valley mapping programme a number of transects were compiled utilising existing borehole data. Two transects have been mapped running in an east/west orientation to the north and south of the site (Fig. 4), with their locations shown on Figure 3. From analysis of the boreholes which lie closest to the site it is clear that the site lies within an area which is on the interface between the River Lea inner and wider floodplains (the inner floodplain being lower ground and more likely to flood). In Transect 1, the presence of peat (shown in brown) is shown in Borehole B, located to the north-east of the site, and more substantial deeper deposits of peat are shown in the adjacent borehole to the east, indicating the location of the river course and the areas of wet ground. The location of these boreholes in relation to the site suggested the site to lie further west than the likely extent of the peat deposits associated within the River Lea.

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Previous works 2.4 Several programmes of archaeological work have been undertaken within the site and its immediate environs. These have not only provided information about the archaeological potential of the surrounding area but also the character of the geological deposits likely to be encountered within the site; summaries of these are outlined below.

MoLAS (1996a) – GLHER ref ELO3348 2.5 Evaluation to the east of the site comprised the excavation of ten trenches, including five located c. 10-50m from the eastern boundary of the site. These trenches recorded no evidence of peat deposits suggesting that extant peat deposits did not extend into the area covered by the evaluation.

MoLAS (1996b) – GLHER ref ELO7357 2.6 Evaluation in September 1996 by the Museum of London was undertaken within the area of the current site (Figs 2 and 5). This comprised 10 trenches of 5m by 5m and hand excavation of 0.5m by 0.5m test pits in opposing corners of each trench down to the level of the river terrace gravels.

2.7 The fieldwork confirmed that the site lies on the boundary between the alluvium/peat deposited in the flood plain of the River Lea and the higher brickearth deposits on the eastern side of the site. The natural river terrace gravel falls from the east to the west and may define the limits of a buried channel or large buried pond. The peat was only apparent in one of the trenches (Trench A; encountered at a depth of 8.16m aOD). In the majority of the trenches struck flint was recovered from the interface between the alluvial deposit and the brickearth or gravel below. Most of the flints represented waste flakes from flint knapping rather than tools.

AOC (2005; 2008) – GLHER ref ELO16618 2.8 Excavation by AOC archaeology group in 2004 revealed evidence of further Mesolithic flintwork at the site of the current IKEA store. This flintwork was interpreted as being redeposited, as during the MoLAS works (1996a), although it was noted that the density of material might suggest it had not been transported far. In addition to this a substantial buried, timber structure was recorded to the east of the excavation area. This was located approximately 80m east of the site, nearer the river courses. Two radiocarbon dates were obtained from preserved wood and dated to between AD430-AD650 and AD340-AD540.

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2.9 Vertical and horizontal timbers were discovered beneath 1.5m of alluvial clay deposits, evidence that the area had been prone to extensive flooding in the medieval period. This was interpreted as a platform located on the edge of a sandbank which would have had dimensions of 8.5m by 6m. This structure appeared to resemble a ‘crannog’, examples of which are rare in early medieval England.

2.10 Running west from the crannog-style structure were several early medieval ditches which merged into one and continued beyond the excavation area to the west. This almost certainly continues into the site and may be associated with further features in this area.

MoLAS (1992) – GLHER ref ELO13177 2.11 A watching brief carried out approximately 100m north of the site where the current Tesco store now stands revealed a concentration of flint implements suggesting some prehistoric activity in this area. Given the nature of the groundworks it was often impossible to enter excavated trenches and as such the definition of the archaeological record is often not of a level with which wider conclusions can be drawn. However, deposits that were recorded suggested the site was once underwater or part of a marsh and finds of a post-medieval date suggest this may have been the case until relatively recently.

AOC (2004) – GLHER ref ELO2409 2.12 Six trenches were excavated prior to a planned extension of the Tesco store 100m north of the site. While no archaeological remains were encountered, and two of the trenches were unrecorded due to ground conditions at the time, two trenches did show a full stratigraphic sequence down to the river terrace gravels.

Chronology: Prehistoric (Pre-AD 43) 2.13 Mesolithic finds are rare within the river valley, but recent excavations to the east of the site have recovered artefacts from the confluence of the River Lea and a tributary valley. The 1996 evaluation within the IKEA site (MoLAS 1996a) recorded 120 struck flint pieces over a widely dispersed area within an alluvial deposit. The assemblage as a whole was dominated by flakes and blades, and the presence of two microliths suggested a Mesolithic element to the assemblage (MoLAS 1996a).

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2.14 The only other prehistoric material recovered from the study area is Iron Age pottery found within same deposits as the Mesolithic flints to the east of the site. Their discovery within the same deposit suggests the artefacts were redeposited through waterborne means, and there is no further evidence for late prehistoric activity in the immediate vicinity of the site.

Roman (AD 43 to AD 410) 2.15 In the Roman period London developed as an urban centre and later the provincial capital at the centre of Roman Britain’s communication system (Perring & Bingham 2000, 147). Edmonton was c. 10km north of Londinium, and would not have been considered part of its territory. However, pockets of Roman activity have been recorded within the study area.

2.16 The site lies just 1.2km to the east of Ermine Street and is close to a Roman settlement active up to the 3rd century AD, identified at Bush Hill Park in Edmonton (several kilometres to the north-west) during excavations in the 1970s. The River Lea was also an important route throughout the Roman period. A piece of redeposited abraded Roman pottery was recovered from the 2004 AOC excavation at the IKEA store east of the site, and a number of items have been recovered from within the River Lea.

Early medieval and medieval (AD 410-1539) 2.17 The site is likely to have been part of the Edmonton marshes throughout the early medieval period, prior to the construction of the Lee Navigation and the deepening of the tributaries such as Pymme’s Brook. This would suggest the area to have been relatively unusable, but the discovery of an early medieval pile dwelling or crannog beneath IKEA to the east of the site has drastically changed the current understanding of early medieval activity within the study area. The site lies on an area of higher ground to the west of the crannog and likely contains related archaeological deposits.

2.18 While the Anglo Saxon Chronicle records King Alfred’s ships pursuing the Danes up the River Lea in AD 896 the marshy riverbanks during the medieval period would have greatly restricted navigation. Edmonton marsh formed a band approximately 1km wide, bordered and crossed by innumerable watercourses, including Pymme’s Brook to the east of the site.

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2.19 An Act of 1571 authorised the City of London to make the Lea navigable as far as Ware in Hertfordshire although little improvement works were carried out in Edmonton until the late 18th and 19th centuries.

2.20 During the later medieval period there were a number of moated manor houses constructed within Edmonton, one of which, Willoughby Moat, was located c. 400m to the north-west of the site. Along the banks of the River Lea, the marshes located upon the alluvial deposits were often utilised for common pasture. It is uncertain whether the site would have continued to lie on the marshland or within the common fields further away from the floodplain at this time, being located very much on the boundary between the two.

Post-medieval and modern (1540-present) 2.21 Rocque’s 1754 map of Middlesex shows the site to lie in the first section of agricultural land next to the flood plain of the River Lea, indicating that by this time the site and its immediate environs had been reclaimed from the floodplain.

2.22 Works to improve the navigability of the River Lea are first documented as early as the 14th century; however the Edmonton cut, which runs closest to the site, was not completed until the late 1770s, and is first seen on the 1802 Enclosure Map of Edmonton. Pymme's Brook was also subject to improvements at this time, being widened and deepened in 1766 and 1772.

2.23 The Gothic Works, a factory manufacturing gas stoves, was constructed to the east of the site by 1914, with an access track linking to the railway line via a route running to the north of the site. The site itself appears to have remained undeveloped during this time, as shown on cartographic sources and aerial photographs. This is consistent with modern excavation at and around the site which have recorded relatively little modern, deep disturbance.

2.24 The site remained a pocket of undeveloped land until the late 1950s when the Willoughby Lane Gas Works extended across the nearby train line and into the site. Proposal plans record the introduction of conveyors and towers crossing the western part of the site with the site itself marked as ‘coke storage’. However, it is unclear as to whether these features were ever constructed.

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3. AIMS AND OBJECTIVES

3.1 The objectives of the evaluation, as detailed with the WSI (CA 2018) were to provide information about the archaeological resource within the site, including its presence/absence, character, extent, date, integrity, state of preservation and quality, in accordance Standard and guidance: Archaeological field evaluation (CIfA 2014). This information will enable the London Borough of Enfield Council to identify and assess the particular significance of any heritage asset, consider the impact of the proposed development upon it, and to avoid or minimise conflict between the heritage asset’s conservation and any aspect of the development proposal, in line with the National Planning Policy Framework (DCLG 2012).

3.2 The specific objectives of the evaluation were to determine if deposits of significant archaeological or palaeoenvironmental potential are present, most notably Late Pleistocene deposits of Enfield silts which overly the natural gravels and which have a high potential to preserve palaeoenvironmental remains as well as archaeological material of upper Palaeolithic date. In addition, the site has the potential for the recovery of material of Mesolithic and later date from alluvial deposits. Data from the trial trench evaluation will be used to address the following aims:

• Confirm and consolidate the Late Pleistocene sedimentary sequence on the site, as demonstrated by recent borehole surveys; • Identify evidence of early human activity and recover, if possible, artefactual/ecofactual evidence with which to date and interpret the activity taking place on the site; • Assess the archaeological, palaeoenvironmental and geoarchaeological potential of the Pleistocene sedimentary units encountered; • Identify, through a programme of environmental sampling and the collection of ecofacts, any activities that may have been carried out in the vicinity of the site and establish the general nature of the environment immediately surrounding the site; • Use the information gained to further develop the deposit model for the site and its surrounds to better understand the topographic setting of early prehistoric human activity in the vicinity; • Identify any other features of archaeological interest that may assist in an understanding of past land use within the Site.

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4. METHODOLOGY

4.1 The fieldwork comprised the excavation of five trenches in the locations shown on the attached plan (Fig. 2). With the exception of Trench 1, each evaluation trench measured 25m by 4m at the top of the existing ground surface and was stepped inwards for safety reasons, exposing an area of between 1m and 2m at the base of each trench. Trench 1 was modified into a test pit measuring 4m by 2m, due to the presence of live services. Trench 2 was shortened to a length of 15m, again due to the possible presence of live services within the western half of the trench. The evaluation ceased at the top of the Pleistocene river terrace gravels, following the methodology set out within the WSI. Trenches were set out on Ordnance Survey National Grid (NGR) co-ordinates using Leica GPS and surveyed in accordance with CA Technical Manual 4: Survey Manual.

4.2 All trenches were excavated by mechanical excavator equipped with a toothless grading bucket. All machine excavation was undertaken under constant archaeological supervision to the top of the first significant archaeological horizon or the natural substrate, whichever was encountered first. Where archaeological deposits were encountered they were excavated by hand in accordance with CA Technical Manual 1: Fieldwork Recording Manual.

4.3 Deposits were assessed for their palaeoenvironmental potential in accordance with CA Technical Manual 2: The Taking and Processing of Environmental and Other Samples from Archaeological Sites, however, no deposits were identified that required sampling. All artefacts recovered were processed in accordance with Technical Manual 3 Treatment of Finds Immediately after Excavation.

4.4 The archive and artefacts from the evaluation are currently held by CA at their offices in Milton Keynes. Subject to the agreement of the legal landowner the artefacts will be deposited with the London Archaeological Archive and Research Centre (LAARC) along with the site archive. A summary of information from this project, set out within Appendix C, will be entered onto the OASIS online database of archaeological projects in Britain.

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5. RESULTS (FIGS 2-11)

5.1 This section provides an overview of the evaluation results; a detailed summary of the recorded contexts can be found in Appendix A. Details of the relative heights of the principal deposits and features expressed as metres above Ordnance Datum (m aOD) appear in Appendix B.

5.2 A broadly similar stratigraphic sequence was recorded across the site. The earliest deposit encountered comprised natural gravels encountered at an average depth of 1.65m bpgl (below present ground level), consisting of loose mid yellow grey to mid grey/brown yellow sub angular stones and sand. This was overlain by alluvial/fluvial layers comprising soft sandy to silty clays, which varied in thickness from 0.14m to 0.85m. The top of the alluvium was encountered at an average depth of 1.05m bpgl across the site and was overlain by post-medieval/modern made ground comprising soft dark brown black sandy silt with occasional brick rubble which averaged 0.51m thick. This was in turn sealed by modern exterior surfaces.

Trench 1 (Figs 2 & 6) 5.3 Trench 1 was constrained by services, with the final footprint of the trench measuring 2.4m by 4m (Fig. 6). Within this trench natural gravels (105), comprising mid yellow grey to mid grey/brown yellow sub angular stones and sand, were encountered at a depth of 1.7m bpgl (8.53m aOD). It was difficult to fully characterise this material as only the uppermost part of the deposit was exposed, but it appears to correlate with Ponders End Gravels. It was overlain by alluvial layers totalling 0.6m thick (1.1m bpgl, 9.13m aOD), the earliest comprising light grey yellow silty clay (104) overlain by mid brown orange silty clay (103). This was overlain by buried soil layer (102; 0.95m bpgl, 9.28m aOD), measuring 0.15m thick and comprising dark grey brown silty loam. This was in turn sealed by modern make-up layers 102 and 101, which were in turn sealed by reinforced concrete (100).

Trench 2 (Figs 2, 7 & 8) 5.4 The natural gravels (207), apparently correlating with the Ponders End Gravels, were revealed at a consistent depth of approximately 1.7m bpgl (8.41m aOD) along the length of the trench (Figs 7 & 8). A layer of possible brickearth (206; 1.05m bpgl, 9.06m aOD) was observed over 3.5m of the eastern end of the trench, directly overlying the gravels. This comprised soft mid brown orange clay sand and

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measured 0.65m thick at its deepest point at the eastern end of the trench, petering out to the west. It was overlain by alluvium (205; 0.85m bpgl, 9.46m aOD), measuring 0.85m thick. It comprised mid brown grey sandy silt, which directly overlay the gravels where the brickearth was not present. This was in turn overlain by made ground (204), comprising dark brown sandy silt, which was in turn sealed by a series of modern surfaces and levelling/bedding layers 203, 202, 201 and 200.

Trench 3 (Figs 2 & 7) 5.5 Natural gravels (305), likely correlating with Ponders End Gravels, were revealed at a consistent depth of 1.5m bpgl (8.61m aOD) along the length of the trench. This was directly overlain by alluvial layer 304 (1.17m bpgl, 8.94m aOD), comprising mid grey blue silty sand and measuring 0.33m thick. This was cut by east/west orientated gully 306, which measured 0.3m wide and 0.08m deep, with an asymmetrical profile and irregular base (Fig. 9; section AA). Following an initial 1m long excavation slot the feature was recorded and then 100% excavated. It contained a single fill (307), deriving from secondary silting, comprising mid blue grey silty clay from which a fragment of undated ceramic building material was recovered. This find is considered likely to be intrusive within this context. Overlying both alluvium 304 and ditch 306 was modern overburden (303, 302 and 301), measuring 1.06m thick. This was in turn sealed by tarmac layer 300.

Trench 4 (Figs 2 & 10) 5.6 The natural gravels (405) were encountered at a depth of 1.56m bpgl (8.61m aOD) in the northern end of Trench 4 and at a depth of 2m bpgl (8.07m aOD) within the southern end of the trench (Fig. 10). They were overlain by the alluvium (404; 1.17m bpgl; 8.9m aOD), measuring 0.4m thick in the northern end of the trench, increasing to a thickness of 0.84m at the southern end of the trench. This was in turn overlain by made ground deposits of sandy silt (402) and sandy gravel (401), which was in turn sealed by tarmac (400).

Trench 5 (Figs 2 & 8) 5.7 The natural gravels (506) were encountered at a depth of 1.8m bpgl (8.68m aOD) in the eastern end of Trench 5 and shallowed towards the western end to 1.4m bpgl (8.28m aOD; Fig. 11). These were overlain by alluvium (505; 1.27m bpgl, 8.81m aOD), measuring 0.54m thick within the eastern end of the trench, thinning to 0.14m thick at the western end. Overlying alluvium 505, buried soil deposit (504) was observed extending from the eastern end of the trench for a length of approximately

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6m. This comprised soft mid grey brown silty loam and measured 0.25m thick. Directly overlying alluvium 505 and buried topsoil 504, where it was present, was modern made ground deposit 503, comprising dark brown sandy silt. This was in turn overlain by a succession of levelling and bedding layers (502 & 501), which were themselves sealed by tarmac (500).

6. DISCUSSION

6.1 The stratigraphic sequences exposed in the evaluation trenches were broadly similar, with some variations reflecting differential deposition environments. The sequences could also be correlated with the depositional sequences established by the earlier surveys of the site and surrounding environment (MoLAS 1996b & Corcoran et al 2011).

6.2 What appears to have been the upper level of the Ponders End Gravel was exposed at between 1.5m and 1.7m bpgl (8.41 to 8.61m aOD) in the north and south-east of the site and 1.4m to 2m (8.07 to 8.68m aOD) in the centre and south-west of the site. This corresponds well with the results from the previous trial pit evaluation of the site, which exposed river terrace gravels at between 8m and 8.8m aOD (MoLAS 1996b). This appeared to show a longitudinal gravel bar running through the centre of the site, with the height of the exposed material falling away to the north (Trench D), east (Trench H) and west (Trench A). This material was also exposed at elevations varying between 6m and 9m aOD in the previous borehole surveys carried out to the north and south of the site (Corcoran et al 2011). These Pleistocene river terrace gravels have elsewhere been shown to contain peat rafts known as the Lea Valley Arctic Bed, which dates to around 28,000 years Before Present.

6.3 Brickearth deposits observed during the 1996 (MoLAS 1996b) evaluation were restricted geographically to a band of land located centrally within the site (Trenches C, E, G, H and J), with an outlying deposit located within Trench Q. This pattern largely corresponds with the results of the current evaluation, with brickearth deposits restricted to the eastern end of Trench 2. These deposits appear to represent mapped Devensian period brickearth deposits of Enfield silts, dating from c. 17,000 BP (BGS 2018).

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6.4 The previous trial pit trenching (MoLAS 1999b) recorded a broad alluvial deposit overlying the river terrace gravels and, where present, the brickearth. The alluvium was on average 0.4m thick and recorded at upper elevations varying between 8.3m and 9.44m aOD. A broadly comparable deposit was recorded within all the trenches during the current evaluation. The upper elevation of the deposit (8.81m aOD to 9.38m aOD) was comparable with the levels recorded in the previous surveys. These fine grained alluvial deposits represent Late Pleistocene/Early Holocene development of the Lea Valley flood plain.

6.5 The buried soil deposits recorded in the 1996 evaluation (MoLAS 1999b) were further recorded within Trenches 1 and 6 of the current evaluation, however, no Arctic Bed or peat deposits were identified within the evaluation.

6.6 A single east/west orientated feature was identified during the evaluation cutting alluvial deposits. The asymmetrical profile, uneven base and slightly sinuous nature of the feature suggest a natural feature, possibly naturally cut by water action and similarly filled by the deposition of silts by slow flowing water action.

6.7 Despite the visual scanning of the spoil no worked flint was recovered.

7. CONCLUSION

7.1 Based on the findings of the evaluation, which did not identify any significant archaeological finds, features, deposits or geoarchaeological sequences, it is recommended that no further archaeological work is required in relation to London Borough of Enfield Council Planning Reference 17/04017/CND.

8. CA PROJECT TEAM

8.1 Fieldwork was undertaken by Tim Havard, assisted by Ralph Brown and Alice Krausova. The report was written by Ralph Brown. The illustrations were prepared by Dan Bashford and Charlotte Patman. The archive has been compiled by Emily Evans, and prepared for deposition by Hazel O’Neill. The project was managed for CA by Stuart Joyce.

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9. REFERENCES

AOC Archaeology Group 2005 A Post-excavation assessment report on an archaeological evaluation and excavation at the IKEA superstore site, Glover Drive, Edmonton, London Borough of Enfield

AOC Archaeology Group 2008 Archaeological Excavations at Glover Drive, Edmonton – An Early Saxon Period Crannog-like structure

BGS (British Geological Survey) 2018 Geology of Britain Viewer http://mapapps.bgs.ac.uk/geologyofbritain/home.html Accessed 29 January 2018

CA (Cotswold Archaeology) 2017 Tottenham IKEA Extension, Edmonton, London: Heritage Desk-based Assessment CA Report: 17392 CA (Cotswold Archaeology) 2018 Tottenham IKEA Extension, Edmonton, London: Written Scheme of Investigation for an Archaeological Evaluation

CIfA, 2014 Standard and Guidance for Archaeological Field Evaluation. Chartered Institute for Archaeologists (Reading)

Corcoran, J., Halsey, C., Spurr, G., Burton, E. and Jamieson, D. 2011 Mapping past landscapes in the lower Lea valley: A geoarchaeological study of the Quaternary sequence

DCLG (Department of Communities and Local Government) 2012 National Planning Policy Framework MOLAS (Museum of London Archaeology Service) 1996a Meridian Point, Glover Drive, London N18, London Borough of Enfield: An Archaeological Evaluation

MOLAS (Museum of London Archaeology Service) 1996a Meridian Point, Glover Drive, London N18, London Borough of Enfield: An Archaeological Evaluation. GLHER ref ELO3348

MOLAS (Museum of London Archaeology Service) 1996b Glover Drive, Edmonton, London N18, London Borough of Enfield: An Archaeological Evaluation. GLHER ref ELO7357

Perring, D. and Bigham, T. 2000 Londinium and its hinterland: The Roman Period in The archaeology of Greater London – An assessment of archaeological evidence for

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human presence in the area now covered by Greater London. Museum of London: Lavenham

17 © Cotswold Archaeology Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation

Key to symbols used in Fig. 4

From Corcoran et al 2011

18 © Cotswold Archaeology Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation

APPENDIX A: CONTEXT DESCRIPTIONS

Trench Context Type Fill Context Context Description Length Width Thickness No of Interpretation (m) (m) (m) 1 100 Layer Surface Concrete and reinforcing bar >25 >4 0.15 1 101 Layer Made ground Soft dark brown black sandy >4 >2 0.55 silt with moderate inclusions of brick and concrete rubble 1 102 Layer Possible buried Soft dark grey silty clay >4 >2 0.15 soil 1 103 Layer Alluvium Soft mid brown orange sandy >4 >2 0.4 clay 1 104 Layer Alluvium Soft light grey yellow sandy >4 >2 0.2 clay 1 105 Layer Natural gravels Loose mid grey yellow sandy >4 >2 gravels 2 200 Layer Surface Tarmac >22 >4 0.09 2 201 Layer Levelling layer Firm mid orange grey 50% >22 >4 0.15 sand and 50% stone occasional CBM and concrete inclusions 0.02-0.05m wide 2 202 Layer Piling mat Firm concrete and CBM >22 >4 0.4 remains rubble 0.04-0.15m 2 203 Layer Surface Concrete and reinforcing bar >3 >4 0.2 2 204 Layer Made ground Soft dark brown black sandy >25 >4 0.35 silt with moderate inclusions of brick and concrete rubble 2 205 Layer Alluvium Soft mid brown grey, >14 >2 0.85 gradually changing to mid orange brown to the west, sandy clay with occasional angular stones 0.01-0.03m 2 206 Layer Brick earth Soft mid brown orange clay >3.5 >2 0.65 sand with no inclusions 2 207 Layer Natural gravels Loose mid yellow grey sub >12 >2 angular stones 0.01-0.04m with sandy patches 3 300 Layer Surface Tarmac >25 >4 0.09 3 301 Layer Levelling layer Firm mid orange grey 50% >25 >4 0.22 sand and 50% stone occasional CBM and concrete inclusions 0.02-0.05m wide 3 302 Layer Piling mat Firm concrete and CBM >25 >4 0.34 remains rubble 0.04-0.15m 3 303 Layer Made ground Soft dark brown black sandy >25 >4 0.5 silt with moderate inclusions of brick and concrete rubble 3 304 Layer Alluvium Soft mid grey yellow sandy >23 >1.5 0.33 clay 3 305 Layer Natural gravels Loose mid yellow grey sub >23 >1.5 angular stones 0.01-0.04m with sandy patches 3 306 Cut Ditch E-W linear with straight >1.5 >1.5 0.08 moderate sides and uneven concave base 3 307 Fill 306 Secondary silting Firm mid blue grey silty clay >1.5 >1.5 1.08 with no inclusions 4 400 Layer Surface Tarmac >25 >4 0.09 4 401 Layer Levelling layer Firm mid orange grey 50% >25 >4 0.31 sand and 50% stone occasional CBM and concrete inclusions 0.02-0.05m wide 4 402 Layer Piling mat Firm concrete and CBM >25 >4 0.26 remains rubble 0.04-0.15m

19 © Cotswold Archaeology Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation

4 403 Layer Made ground Soft dark brown black sandy >25 >4 0.5 silt with moderate inclusions of brick and concrete rubble 4 404 Layer Alluvium Soft mid grey yellow sandy >23 >1.1 0.4 clay 4 405 Layer Natural gravels Loose mid brown yellow >23 >1.1 sandy gravels with sandy patches 5 500 Layer Surface Tarmac >23.5 >4 0.09 5 501 Layer Levelling layer Firm mid orange grey 50% >23.5 >4 0.14 sand and 50% stone occasional CBM and concrete inclusions 0.02-0.05m wide 5 502 Layer Piling mat Firm concrete and CBM >23.5 >4 0.41 remains rubble 0.04-0.15m 5 503 Layer Made ground Soft dark brown black sandy >23.5 >4 0.63 silt with moderate inclusions of brick and concrete rubble 5 504 Layer Buried topsoil Soft mid grey brown silty >7.5 >1.3 0.25 loam no inclusions 5 505 Layer Alluvium Soft mid grey yellow silty clay >21.5 >1.3 0.54 with 1% small sub angular stones 5 506 Layer Natural gravels Loose mid grey yellow sandy >21.5 >1.3 gravels

20 © Cotswold Archaeology Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation

APPENDIX B: LEVELS OF PRINCIPAL DEPOSITS AND STRUCTURES

Levels are expressed as metres Above Ordnance Datum and as metres below current ground level (in parenthesis).

Trench 1 Trench 2 Trench 3 Trench 4 Trench 5 Current ground level 10.23m 10.11m 10.11m 10.07m 10.08m (0.00m) (0.00m) (0.00m) (0.00m) (0.00m) Top of alluvium 9.18m 9.46m 8.94m 8.9m 8.81m (1.1m) (0.85m) (1.17m) (1.17m) (1.27m) Top of gravels 8.53m 8.41m 8.61m 8.51m N end 8.28m E end (1.7m) (1.7m) (1.5m) 8.07m S end 8.68m W end (1.56m-2m) (1.4m-1.8m)

21 © Cotswold Archaeology Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation

APPENDIX C: OASIS REPORT FORM

PROJECT DETAILS Project Name Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation Short description An archaeological evaluation was undertaken by Cotswold Archaeology in April 2018 of land off Glover Drive, Edmonton, London Borough of Enfield. The evaluation comprised the excavation of five evaluation trenches to a depth of between 1.5m and 2m below the present ground surface (bpgs). Geoarchaeological interest in the site derives from its location within the Lea Valley, within an area which is on the interface between the River Lea inner and its wider floodplains. Archaeological interest is derived from the discovery within the site of 120 pieces of struck flint recovered from an alluvial deposit, some of which are attributable to the Mesolithic period, as well as the discovery of an early medieval pile dwelling or crannog located to the immediate east of the site.Pleistocene river terrace gravels were recorded at between 1.4m and 2m bpgs, at the base of the exposed sequence across the site. These were overlain in the north of the site by brickearth deposits. Comparable deposits had previously been recorded during trial pit evaluation of the site, which represented Devensian period brickearth deposits of Enfield silts, dating from c. 17,000 BP. Significant fine-grained alluvial/fluvial deposits were also recorded across the site overlying both the river terrace gravels and, where present, the brickearth. The top of this alluvium was encountered at an average depth of 1.17m bpgs. These fine grained alluvial deposits represent Late Pleistocene/Early Holocene development of the Lea Valley flood plain. Cutting the top of the alluvium within Trench 3 was an undated, east/west orientated feature, most likely representing a natural erosion gully. The geological sequence in each trench was overlain by made ground deposited during the 19th and 20th centuries and capped by modern external surfaces of concrete or tarmac. Project dates 9/04/18-17/04/18 Project type Evaluation Previous work Field evaluation (MOLA 1996) Desk-based Assessment (CA 2017) Future work Unknown PROJECT LOCATION Site Location Tottenham IKEA, Glover Drive, Edmonton, London Borough of Enfield Study area (M2/ha) 0.6ha Site co-ordinates 535245 191749 PROJECT CREATORS Name of organisation Cotswold Archaeology Project Brief originator n/a Project Design (WSI) originator Cotswold Archaeology Project Manager Stuart Joyce Project Supervisor Tim Havard MONUMENT TYPE None SIGNIFICANT FINDS None PROJECT ARCHIVES Intended final location of archive Content Physical Museum of London CBM Paper Museum of London WSI, pro forma recording sheets, registers Digital Museum of London Digital photographs, survey data BIBLIOGRAPHY CA (Cotswold Archaeology) 2018 Tottenham IKEA Extension, Edmonton, London: Archaeological Evaluation. CA typescript report 18222

22 5 533000 5 535000 5 537000 3 3 3 3 5 7 0 0 0 0 0 0 0 0 0

119300093000

119100091000

N Andover 01264 347630 Hertfordshire Cirencester 01285 771022 Essex Cotswold Exeter 01392 826185 Enfield Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]

PROJECT TITLE Tottenham IKEA, Edmonton, London London31

FIGURE TITLE Site location plan Kent 0 1km Surrey DRAWN BY CP PROJECT NO. 661041 FIGURE NO. © Crown copyright and database rights 2018 CHECKED BY DJB DATE 23/04/2018 Ordnance Survey 0100031673 APPROVED BY SRJ SCALE@A4 1:25,000 1 5 5 5 3 3 3 5 5 5 2 3 4 0 0 0 0 0 0

Glove ditch r Drive 306

T1 site boundary MOLA Test Pitting Survey 1996 AOC Excavation 2005 191800 evaluation trench

T2 archaeological feature (excavated/unexcavated) modern

section location

T3 alignment of Saxon Ditch

o T5

i 191700

a 0 25m

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, n Cirencester 01285 771022

t n Exeter 01392 826185

m Milton Keynes 01908 564660

E w www.cotswoldarchaeology.co.uk

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I PROJECT TITLE

h n Tottenham Ikea, Edmonton, London

4 FIGURE TITLE

: Trench location plan

n e DRAWN BY CP PROJECT NO 661041 FIGURE NO.

m u CHECKED BY DJB DATE 01/05/2018

c o APPROVED BY SRJ SCALE@A3 1:750 2

D N 3 FIGURE NO. (after BGS) 01908 564660 cotswoldarchaeology.co.uk 01285 771022 @ 01264 347630 01392 826185 Ordnance Survey 0100031673 Ordnance Survey

www.cotswoldarchaeology.co.uk 661041 23/04/2018 1:10,000

enquiries Andover Cirencester Exeter Milton Keynes w e (after Corcoran et al 2011) (after Corcoran 1:10,000 PROJECT NO. DATE SCALE@A3 site boundary transect borehole of peat predicted extent End Ponders of extent predicted deposits) Beds (Arctic Gravels of Enfield Silts extent course water DJB AO SRJ Cotswold Archaeology 0 500m © Crown copyright and database rights copyright 2017 © Crown PROJECT TITLE IKEA, Edmonton, London Tottenham FIGURE TITLE geological model of site MOLA DRAWN BY DRAWN CHECKED BY APPROVED BY 2m 0 B E B

atic sections through site

che peat

S A B 1:2500 alluvial deposit Ikea 0 100m A

553700037000 River Lea Lea River D B

A River Lea Navigation Lea River B modern

brickearth

1:1000 Site Pymme’s Brook Pymme’s inset A 0 50m C 553500035000 ) after MOLA 1996 alluvial deposit Schematic sections ( peat A W

553300033000 AOD 9.5m 0 0 0 0 0 0 3 1

Transect 1 Transect Transect 2 9 9 1 193000 1 191000 Transect 1 (MOLA 2011)

Transect 2 (MOLA 2011)

Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]

PROJECT TITLE Tottenham Ikea, Edmonton, London

FIGURE TITLE MOLA borehole transect

DRAWN BY CP PROJECT NO. 661041 FIGURE NO. CHECKED BY DJB DATE 23/04/2018 APPROVED BY SRJ SCALE@A4 N/A 4 5

The site, looking east

Trench 1, looking south (scale 1m)

Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]

PROJECT TITLE Tottenham Ikea, Edmonton, London

FIGURE TITLE Photographs

DRAWN BY CP PROJECT NO. 661041 FIGURE NO. CHECKED BY DJB DATE 23/04/2018 APPROVED BY SRJ SCALE@A4 N/A 5 & 6 7

Trench 2, looking west (scales 1m)

East end of Trench 2, looking south (scales 1m)

Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]

PROJECT TITLE Tottenham Ikea, Edmonton, London

FIGURE TITLE Photographs

DRAWN BY CP PROJECT NO. 661041 FIGURE NO. CHECKED BY DJB DATE 23/04/2018 APPROVED BY SRJ SCALE@A4 N/A 7 & 8 Section AA

NS 8.9m AOD 307 gully 306

0 1:20 1m

Gully 306, looking east (scale 0.3m)

Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]

PROJECT TITLE Tottenham Ikea, Edmonton, London

FIGURE TITLE Gully 306: section and photograph

DRAWN BY CP PROJECT NO. 661041 FIGURE NO. CHECKED BY DJB DATE 23/04/2018 APPROVED BY SRJ SCALE@A4 1:20 9 10

Trench 4, looking north (scale 1m)

East end of Trench 5, looking south (scale 1m)

Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]

PROJECT TITLE Tottenham Ikea, Edmonton, London

FIGURE TITLE Photographs

DRAWN BY CP PROJECT NO. 661041 FIGURE NO. CHECKED BY DJB DATE 23/04/2018 APPROVED BY SRJ SCALE@A4 N/A 10 & 11