LAND ADJACENT TO COBBINS BROOK/BROOKMEADOW WOOD ,

ARCHAEOLOGICAL MONITORING OF GEOTECHNICAL TEST PITS

Client: Halcrow Group Ltd FAU project number: 1369 NGR: TL 412 021 Date of fieldwork: 7/6/04 to 8/6/04

SUMMARY Archaeological monitoring of geotechnical test pits within the area of a proposed flood alleviation scheme at Cobbins Brook, Upshire has uncovered no direct evidence for significant archaeological or palaeo-environmental remains. The consistent use of the area for meadow and woodland over a prolonged period of time seems likely from the absence of archaeological finds, features and archaeological horizons and the propensity of the area to flood.

1.0 INTRODUCTION 1.1 The archaeological monitoring of twelve geotechnical test pits in advance of the proposed construction of a flood alleviation scheme at Upshire, Essex was carried out by Essex County Council Field Archaeology Unit (ECC FAU) on behalf of Halcrow Group Ltd, acting for the Environment Agency (Fig 1).

2.0 LOCATION AND FORM OF FLOOD ALLEVIATION SCHEME

2.1 The flood alleviation scheme is situated in mixed farmland to either side of Cobbins Brook, which is a tributary of the . The brook lies north of the of the village of Upshire, and flows in a south-easterly direction towards .

2.2 The flood alleviation scheme will consist of a 400m long earth embankment. The embankment will straddle Cobbins Brook and will be constructed from material extracted from borrow pits from within the area of the flood alleviation scheme. The flood alleviation scheme will eventually contain up to 300,000m2 of flood water.

3.0 PLANNING BACKGROUND

3.1 The archaeological monitoring of the geotechnical test pits was stipulated by Essex County Council Heritage Advice Management and Promotion (ECC HAMP), in consultation with the Environment Agency (ECC HAMP 2004). The work was stipulated in response to an Environmental Impact Assessment Scoping Report, in which it was concluded that possible archaeological deposits contained within the

1 alluvium of Cobbins Brook could be affected by the construction of the flood alleviation scheme.

3.2 Further advice on evaluation/mitigation measures relating to the flood alleviation scheme will be contained in the Cultural Heritage report in the Environmental Impact Assessment, which will be produced in July 2004.

4.0 ARCHAEOLOGICAL AND GEOLOGICAL BACKGROUND

4.1 The proposed earth embankment and related works lie within an area designated in 1992 in the Local Plan as ‘ancient landscape’ (Essex Heritage Conservation Record (EHCR) 16683). Archaeological finds of all periods have been made in the general area north of Waltham Abbey, and the northern Thames tributaries, including the Lea Valley and its tributaries, are considered to be of national significance for the survival of prehistoric sites within alluvial deposits (see 4.2 below).

4.2 Contained within the area of the Lea valley and its tributaries are rare and important Mesolithic and Neolithic sites (Fig. 4) (Jacobi 1980). The most important at these is at in where working floors and microliths are known to be present sealed below or stratified within peat deposits formed within the flood plain of the course of the Lea (Warren et al 1934). From Mead, to the east of Broxbourne, comes an important group of Neolithic artefacts, including part of a polished flint axe head. An important assemblage of Mesolithic worked flint artefacts, now held at the British Museum, was found in a clay pit cut into the Claygate Beds at High Beech in Epping Forest (Warren 1913). Included amongst the wide variety of worked flint pieces from this site are microliths and scrapers. Groups of Mesolithic flints artefacts also come from the Cloister site, close to the Lea and Cobbins brook, in Waltham Abbey (Huggins 1970). Elsewhere in the area the discovery of Mesolithic flint artefacts as surface finds in the valleys around and Epping is relatively common.

An apparent close association between Mesolithic sites and river valleys is probably partly related to the use of the rivers as principle route-ways, at a time when large parts of what is now Britain would have been difficult to travel through because they would have been densely wooded.

4.2 Within the area of the proposed flood alleviation scheme deposits of alluvium lie above Head and Eocene London Clay.

2 5.0 AIMS AND OBJECTIVES

5.1 The main aim of the monitoring of the test pits was to provide a very basic level of information on stratigraphy and the potential for environmental study.

5.2 During the monitoring particular attention was paid to the following:

 The survival of alluvial deposits, especially the presence or absence of a palaeosol, and whether there was evidence for truncation or erosion  The preservation of deposits within cut features or natural channels and hollows  The preservation of organic deposits, such as peat beds, with ecofactual evidence with potential analysis  Deposit formation in general  The presence of artefacts

6.0 METHOD

6.1 Twelve geotechnical test pits (numbered from 1 to 13 - number 9 not used/excavated) were excavated by Halcrow Group Ltd using a mechanical excavator with a narrow toothless bucket. The test pits were approximately 1.6m long and 0.8m wide, and between 2.5m and 3.3m deep.

6.2 Test pits 1, 2, 3, 5, 6 and 13 were located close to the brook, below the 35m contour line. Tests pits 4, 8, 10, 11 and 12 were placed higher up sides of the valley, between the 35m and 40m contour lines. Test pit 7 lay at the far east end of the alleviation scheme, on the brow of a hill (Fig. 2).

6.3 The test pits were assessed for their palaeo-environmental potential and were inspected for archaeological finds and deposits.

6.4 The depth of each deposit below present day ground level was recorded and each deposit was individually numbered and described. The approximate location of each pit was recorded by eye. The height above sea-level of each deposit was not recorded.

6.4 No environmental samples were taken because no well-stratified deposits containing plentiful artefacts or carbonised or waterlogged material were encountered.

7.0 FIELDWORK RESULTS

7.1 Forty-seven deposits were identified (Table 1 and figures 5 to 16). Three deposits apiece were identified in test pits 4, 7, 8, 10, 11, 12 and

3 13, four deposits apiece in pits 3, 5, and 6, and six and seven deposits apiece in pits 2 and 1 respectively.

7.2 Apart from the interface between deposits 36 and 37 in test pit 10, the interfaces between deposits were easy to identify.

7.3 The water table was encountered in only two of the test pits. In test pit 1 it was c. 1.8m below ground level, and in test pit 2 c. 1.95m below ground level.

7.4 No artefacts were seen in the test pits or in the extracted deposits. The test pits uncovered no cut-features, organic deposits or palaeosols. The only visible organic remains, apart from carbonised wood in a few of the deposits, were infrequent small pieces of soft black wood in deposit 5 in test pit 1.

7.5 Many of the deposits were encountered in more than one test pit (Table 1: deposit groups A, C, H, J and L).

7.6 In eleven of the twelve test pits, the test pit was taken down to the level of the London Clay (Table 1: deposit group L). The median depth of the London Clay, which varied from 0.7m to 2.9m, was 1.95m.

7.7 Deposits of yellowish/orange brown silt, sand, clay and gravel overlay the London Clay in four of the test pits (Table 1: test pits 2, 7, 8 and 13, deposit groups I, J and K). These deposits were at their thickest in test pits 7 and 8, on the high ground at the east end of the flood alleviation scheme.

7.8 Grey soft silt sand clay and gravel overlay the yellowish/orange brown soft silt sand and gravel in test pit 2 and the London Clay in test pits 1, 3, 5 and 6 respectively (Table 1: deposit group H). It occurred in the test pits closest to the north side of the brook and had a median depth of 0.8m.

7.9 Single or double deposits of silt clay with either none or very few inclusions were seen in the upper sections of all of the test pits apart from test pit 7, which was located above the 40m contour line (Table 1: deposit groups B, C, F and G). In contrast to the other test pits, in between the two deposits of silt clay in test pit 1 were thin bands of brownish grey clay silt and brownish grey silt sand respectively. Plotting of the thickness of the silt clay suggests that it is at its shallowest in the approximate centre of the proposed flood alleviation scheme (Fig. 3).

4 8.0 CONCLUSIONS

8.1 The monitoring of the geotechnical test pits has confirmed that deposits of alluvium lie across most of the area of the proposed flood alleviation scheme. No alluvium appears to be present above the 40m contour line, on the top of the hill around test pit 7.

8.2 In contrast to other sites, such as the Rivers Lea, Stour and Blackwater, where deep deposits of organic silt and peat have been uncovered through test pitting, no organic remains appear to be present within the vicinity of the proposed flood alleviation scheme (Bedwin 1991, Brown and Germany 2002). If buried organic remains are still present within the vicinity of the brook then the most probable location for this is within the area of the waterlogged test pits 1 and 2, where alluvial deposit 5 in test pit 1 was found to contain infrequent small pieces of wood.

8.3 The absence of archaeological horizons, features and finds in the test pits and the propensity of the land to flooding makes it unlikely that the area of the flood alleviation scheme has been intensively settled in the distant and recent past. Because of the area’s propensity to flooding it seems much more likely that it has always been used for woodland and/or pasture.

8.4 Fluvial deposits relating to Cobbins brook are possibly represented by the distinctive gravel-rich deposits of grey silt sand clay beneath the alluvium in test pits 1, 2, 3, 5 and 6, which are situated close to the north edge of the brook.

8.5 Deposit groups I, J and K in test pits 2, 7, 8 and 13 at the east end of the proposed alleviation scheme are probably glacial in origin (?Head).

5 Acknowledgements

Essex County Council Field Archaeology Unit undertook the archaeological monitoring of the geotechnical test pits on behalf of Halcrow Group Ltd.

Especial thanks are due to the following people for their specialist help and assistance: Stephen Lee and Simon Hunt of Halcrow Group Ltd; Hazel Martingell; Dr Andrew Haggart of the Department of Earth and Environmental Sciences, at the University of Greenwich at Medway, Kent; and Peter Murphy, English Heritage East of Regional Advisor for Archaeological Science, 24 Brooklands Avenue, Cambridge.

Bibliography

Bedwin, O. 1991 ‘An early Flandrian peat in the Lea Valley; excavations at the former Royal Ordnance Factory, Enfield Lock 1990’. Essex Arch. Hist. 22, 162-63

Brown, N. and 2002 ‘Jousting at windmills: the Essex cropmark enclosures project’. Germany, M. Essex Arch. Hist. 33, 8-53

ECC HAMP 2004 Archaeological monitoring of geotechnical test pits on land adjacent to Cobbins Brook/Brookmeadow Wood, Upshire, Essex Archaeological brief, Essex County Council Historic Environment Branch.

Huggins, P.J. 1970 ‘Waltham Abbey monastic site and prehistoric evidence, 1953- 1967’. Trans. Essex Archaeol. Soc. 3, 216-66

Jacobi, R.M. 1980 ‘The Mesolithic of Essex’, in Buckley, D.G. (ed.) Archaeology in Essex to AD 1500. CBA Res. Rep. 34, 14-25

Warren, S.H. 1913 ‘”Pigmy flints” in Epping Forest’, Essex Natur. 16, 265-82

Warren, S.H., 1934 ‘An early Mesolithic site at Broxbourne sealed under Boreal peat’. Clark, J.G.D., J. Roy. Anthropol. Inst. 64, 101-28 Burkitt, M.C. and Godwin, H. and M.C.

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