Nightingale Estate, Hackney and Ponds Farm 2, Aveley

Executive Summary

Nightingale Estate, Hackney and Ponds Farm 2, Aveley: accessing deep Pleistocene deposits with palaeoenvironmental potential.

Pleistocene deposits may be at significant depth; well beyond that which can be reached by conventional archaeological trenching. The following case study presents an approach taken to capture such deposits on two sites in Greater London: Nightingale Estate in Hackney and Ponds Farm 2 in Aveley, both undertaken in advance of commercial development.

Neither of these sites preserved Palaeolithic remains, but contained organic deposits with high palaeoenvironmental potential. Trench boxes and/or boreholes were used to retain deposits from up to 13m below ground surface on both sites. This was followed by a programme of high-resolution, multi-proxy, laboratory-based analysis.

The resultant findings have enhanced knowledge and understanding of the Quaternary sequence, providing new evidence for a larger number of separate temperate episodes than previously recognised. In addition, the findings demonstrate the value of palaeoenvironmental reconstructions even in the absence of direct archaeological evidence.

Keywords

Where: East London
Region: South-East
Palaeolithic period(s): early Middle Palaeolithic (MIS 9–7)
Type of investigation: Literature review; Fieldwork; Post-excavation analysis and publication
Methods: Boreholes (Ponds Farm 2); Deep trenching (Nightingale Estate); Dating (Optically Stimulated Luminescence, Amino Acid Racemisation; Uranium series); Palaeoenvironmental assessment and analysis (both sites)
Type(s) of deposit: Made Ground; River Terrace Deposits (gravel, organic-rich sediment)
Features of interest: Media attention (Nightingale Estate)

Investigations were undertaken at Nightingale Estate, Hackney from 2000, and at Ponds Farm 2, Aveley from 2010.

Both sites went through the following main stages:

1. Desk-based review. All available on-site geotechnical borehole and test-pit data were reviewed together with nearby Quaternary records. These data were used to produce a fieldwork and post-excavation project proposal.
2. Fieldwork. Deep excavations and/or boreholes were put down at the site to obtain samples for post-excavation analysis, and reports prepared on the results.
3. Post-excavation assessment & analysis. Comprising a programme of multi-proxy laboratory-based investigations.
4. Publication. The Nightingale Estate site was published in Quaternary Science Reviews (Green et al. 2006); the Pond Farm 2 publication is in preparation.

Development Context

Investigation of Nightingale Estate and Ponds Farm 2 was required as a consequence of proposed commercial development. Both sites are situated on remnants of different Thames terrace deposits, both of which include fine-grained organic-rich sediments, for which there is well-documented evidence of palaeoenvironmental remains.

Both the Nightingale Estate and Ponds Farm 2 site discussed here were therefore considered of importance, because of the opportunity to reinvestigate and confirm the chronology of the deposits, and attempt detailed palaeoenvironmental reconstruction for the time-period represented.

Such investigations were considered appropriate because of the rich Palaeolithic record at sites of similar age elsewhere in south-east England (early Middle Palaeolithic, associated with early Neanderthals; see also Southall Gasworks Case Study) and despite the absence of archaeological evidence at the sites themselves.

Archaeological Context

Nightingale Estate in Hackney is located on a remnant of River Terrace Gravels (Figure 1) mapped by the British Geological Survey as Middle Pleistocene Hackney Gravel. Gibbard (1994) recorded up to 2.0m of organic sediments within the gravel at the Nightingale Estate and assigned the organic remains to the last, Ipswichian Interglacial (MIS 5e; see Guidance: Figure 8).

However, Bridgland (1994) regarded the gravel at the Nightingale Estate as part of the Lynch Hill Gravel, of MIS 8 age (Figure 2), and inferred an MIS 9 age for any underlying organic remains. In the context of these significantly different interpretations there was a strong case for detailed analysis of any organic remains that came to light during pre-development investigations at the Nightingale Estate.

This case was further strengthened by the fact that, at the time that the work outlined here was carried out, only a small number of MIS 9 sites had been recognised in Europe, with few where detailed palaeoenvironmental and chronological reconstruction had been possible. There was therefore potential for remains of national importance (‘the remains belong to a period or geographic area where evidence of a human presence is particularly rare’), according to the criteria outlined in the Historic England guidance document ‘Sites of Early Human Activity: Scheduling Selection Guide‘ (see also Guidance: Section 8).

The Ponds Farm 2 site in Aveley is located on River Terrace Gravel mapped by the British Geological Survey as Taplow Gravel (Figure 1). The gravel is treated by Bridgland (1994) as part of the Mucking Formation, which comprises MIS 7 Aveley Interglacial deposits sandwiched between MIS 6 Mucking Upper Gravel and MIS 8 Mucking Lower Gravel (Bridgland 1994, 1995a, 1995b) (Figure 2).

The Aveley Interglacial deposits principally comprise sands, silts and clays, with extensive lenses of organic material. Ponds Farm 2 is located adjacent to the famous Sandy Lane Quarry site, which yielded a rich variety of vertebrate fossils (including mammoth and elephant), Mollusca, Ostracoda, and pollen within these deposits (Blezard 1966; Carreck 1966; West 1969; Bridgland 1994, 1995a; Sutcliffe 1995).

Methodology & Research Questions

Fieldwork

There were significant practical constraints at both sites with the upper surface of the organic deposits of interest at least 5m below ground surface (bgl) and, at Ponds Farm 2, extending to 13m bgl, well beyond a depth suitable for conventional archaeological trenching. Methods of successfully accessing the deep deposits were therefore a key consideration for both projects.

At the Nightingale Estate, a combination of deep-excavation and coring techniques were undertaken to obtain the >8m sequence (Figure 3). The deep excavation extended to 5.1m bgl, reaching the upper part of the organic-rich deposits. This was undertaken using a trench-box and coordinated by the developer. The sediments were sampled and recorded above the water-table; bulk samples were collected at a 10cm resolution through the accessible part of the organic-rich deposits, together with two overlapping sets of columns (Green et al. 2006).

Two 3m-deep boreholes were then put down through the base of the trench-box to reach the lower part of the organic-rich deposits and contact with the underlying gravel. The cores were put down using an Atlas Copco 2-stroke percussion engine and Eijkelkamp windowless sampler. This method collects continuous samples in 1m-long, 5cm-thick plastic liners. At Ponds Farm two boreholes were put down from the surface to reach the 8–13m-deep sequences. In this instance, a geotechnical cable-percussion rig was used, and the samples were collected in 0.45m-long, 10cm plastic liners (known as U100 samples; Figure 4).

Post-excavation assessment & analysis

A programme of high-resolution multi-proxy laboratory investigations was undertaken on the samples from both sites (Figures 3 and 4) incorporating:

• Sedimentology – including sediment description, deposit modelling, organic-matter determinations, clast and particle size analysis;
• Chronology (dating) – including Uranium series (U-series), Amino Acid Racemisation (AAR) and Optically Stimulated Luminescence (OSL; see also Guidance: table 4);
• Palaeobotany (plant remains) – including pollen, plant macrofossils (seeds and wood), diatoms and charophytes;
• Palaeozoology (animal remains) – including vertebrates, Mollusca, Ostracoda, Foraminifera, insects and earthworm granules.

These laboratory-based investigations were undertaken over two stages. During the initial assessment stage, the sedimentological work was completed, and a relatively small number of samples was investigated to establish the preservation and concentration of plant and animal remains.

A limited amount of dating was also attempted to provide a baseline chronology for each sequence. During the analysis phase, those techniques demonstrating high potential during the assessment phase were investigated at high resolution (see Figures 3 and 4).

Results

The results of the investigation provided two high-resolution palaeoenvironmental reconstructions for two different temperate periods during the Pleistocene.

The results of the OSL dating and the characteristics of the palaeoenvironmental remains (plants and animals) confirmed that the organic-rich deposits from the Nightingale Estate date to MIS 9 rather than MIS 5e. At the time of publication in Green et al. (2006), the findings represented one of the first terrestrial palaeoenvironmental reconstructions in western Europe for MIS 9. During this period, the plant and animal remains indicate climatic conditions with warmer summers than the present in south-east England, and similar winter temperatures.

As at the Nightingale Estate, there has been some debate regarding the age of the Pleistocene interglacial deposits in the Aveley area (e.g. Bridgland 1995a). The three independent methods of dating used at Ponds Farm 2 all indicate that the deposits are of MIS 7 age. Furthermore, the palaeoenvironmental reconstruction both complements and enhances those from nearby sites such as Sandy Lane Quarry and the original Ponds Farm site (Allen et al. 2011).

Significance

Overall, the work at the two sites has demonstrated the success of: (1) deep excavations and different borehole methodologies to capture undisturbed sedimentary sequences at depth, and (2) the adoption of a multi-proxy and high-resolution laboratory-based approach to provide detailed palaeoenvironmental reconstructions.

Furthermore, the work has enhanced knowledge and understanding of the Quaternary sequence, providing new evidence for a larger number of separate temperate episodes than was formerly recognised (Mitchell et al. 1973; see Guidance: Figure 8). Indeed the results indicate that MIS 7 and MIS 9 were at least equal to, or warmer than today.

Finally, the findings demonstrate the value of palaeoenvironmental reconstructions even in the absence of direct archaeological evidence for artefacts at these sites, as they provide valuable contextual detail through which early Neanderthal activity in Britain can be better understood. The sites have either been published (Nightingale Estate; Green et al. 2006) or publication is pending (Ponds Farm 2).

As an additional outcome, the findings from Nightingale Estate attracted significant media attention. The results from the investigation were reported in several newspapers and television reports, reflecting a strong public interest in the Palaeolithic period (Figure 5).

Key Insights

The results from both sites demonstrate the valuable palaeoenvironmental information that can be gained from a programme of detailed field- and laboratory-based investigation. Furthermore, in both instances the sediments of interest were preserved at some depth below the present-day surface, and potentially below the level of development impact. However, such investigation is highly desirable where the outcome has an important bearing on our understanding of the Palaeolithic resource.

References

Allen, P., Black, S., Branch, N.P., Batchelor, C.R., Green, C.P., Young, D.S., Athersuch, J., White, T., Penkman, K., Schwenniger, J-L., Schreve, D., Elias, S., Austin, P. and Field, M. 2011. 'Ponds Farm 2, Aveley, Essex: palaeoenvironmental analysis report'. Quaternary Scientific (QUEST) Unpublished Report March 2011; Project Number 001/10.

Blezard, R.G. 1996. 'Field meeting at Aveley and West Thurrock'. Proceedings of the Geologists’ Association 77: 273–276.

Bridgland, D.R. 1994. 'Quaternary of the Thames'. Chapman and Hall (Geological Conservation Review Series No. 7): London.

Bridgland, D.R. 1995a. 'Aveley: The Aveley Silts and Sands'. In D.R. Bridgland, P. Allen and B.A. Haggart (eds.) The Quaternary of the Lower Reaches of the Thames: Field Guide: 185–188. Quaternary Research Association: Durham.

Bridgland, D.R. 1995b. 'The Quaternary sequence of the eastern Thames basin: problems of correlation'. In D.R. Bridgland, P. Allen and B.A. Haggart (eds.) The Quaternary of the Lower Reaches of the Thames: Field Guide: 35–52. Quaternary Research Association: Durham.

Bridgland, D.R., Antoine, P., Limondin‐Lozouet, N., Santisteban, J.I., Westaway, R. and White, M.J. 2006. 'The Palaeolithic occupation of Europe as revealed by evidence from the rivers: data from IGCP 449'. Journal of Quaternary Science 21(5): 437–455.

Bridgland, D.R., Preece, R.C., Roe, H.M., Tipping, R.M., Coope, G.R., Field, M.H., Robinson, J.E., Schreve, D.C. and Crowe, K. 2001. 'Middle Pleistocene interglacial deposits at Barling, Essex, UK: evidence for a longer chronology for the Thames terrace sequence'. Journal of Quaternary Science 16: 813–840.

Carreck, J.N. 1966. 'Current field research: discovery of a second skeleton of straight-tusked elephant at Aveley, Essex'. Bulletin of the Area Museums Service of South East England 2: 9–10.

Gibbard, P.L. 1994. 'Pleistocene History of the Lower Thames Valley'. Cambridge University Press: Cambridge.

Green, C.P., Branch, N.P., Coope, R.G., Field, M.H., Keen, D.H., Wells, J.M., Schwenniger, J-L., Preece, R.C., Schreve, D.C., Canti, M.G., and Gleed-Owen, C.P. 2006. 'Marine Isotope Stage 9 environments of fluvial deposits at Hackney, north London, UK'. Quaternary Science Reviews 25: 89–113.

Mitchell, G.F., Penny, L.F., Shotton, F.W. and West, R.G. 1973. 'A correlation of Quaternary deposits in the British Isles'. Geological Society of London (Special Report No. 4): London.

Sutcliffe, A.J. 1995. 'The Aveley Elephant Site, Sandy Lane Pit (TQ553807)'. In D.R. Bridgland, P. Allen and B.A. Haggart (eds.) The Quaternary of the Lower Reaches of the Thames: Field Guide: 189–200. Quaternary Research Association: Durham.

West, R.G. 1969. 'Pollen analyses from interglacial deposits at Aveley and Grays, Essex': Proceedings of the Geologists Association 80: 271–282.

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