WATERLOO WHARF UXBRIDGE, PHASE II: GEOARCHAEOLOGICAL ... · London Clay Formation that dates to the Eocene epoch 56 to 33.9 million years BP. To the east are deposits of the Langley

October 2015

Report Number: 1516-8

WATERLOO WHARF

UXBRIDGE, PHASE II:

GEOARCHAEOLOGICAL

MONITORING OF

EVALUATION TRENCHES

Nick Watson

ARCA

Department of Archaeology

University of Winchester

Winchester

SO22 4NR

http://www.arcauk.com

Prepared for Cotswold

Archaeology

Waterloo Wharf, Phase II: Geoarchaeological monitoring of evaluation trenches.

Version Date Status* Prepared by Author’s signature Approved by Approver’s

Signature

01 12/10/15 E Nick

Watson

*I – Internal draft; E – External draft; F - Final


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CONTENTS

Contents ........................................................................................... 1

Figures .............................................................................................. 1

Summary .......................................................................................... 2

1. Introduction ................................................................................ 3

2. Methodology ................................................................................ 5

3. Evaluation Trench Stratigraphy................................................... 7

3.1 Colney Street Gravel Member. ............................................... 7

3.2 Alluvium. .............................................................................. 9

3.3 Organic Mud ....................................................................... 11

3.4 Made Ground ...................................................................... 11

4. Assessment ............................................................................... 12

4.1 Late Quaternary sedimentary sequence. .............................. 12

4.2 Comparison with Three Ways Wharf and Riverside Way. ..... 13

4.3 Archaeological and palaeoenvironmental potential. ............. 13

5 Acknowledgements .................................................................... 14

6. Bibliography ............................................................................. 15

Appendix 1: Evaluation trench Logs ................................................ 17

FIGURES

Figure 1. Site plan. Canal section: south to north T1, WS05, WS03,

T2, T3 LCP01. Waterloo Road section: south to north T9, T8,

WS04, T7, WS02, T6, T5, WS01. Evaluation trenches are marked

in blue and green and boreholes in black. (Plan courtesy of

Cotswold Archaeology)................................................................. 6

Figure 2. Waterloo Road section south to north. Vertical exaggeration

x5 ............................................................................................... 8

Figure 3. Canal section south to north. Vertical exaggeration x5. ....... 9

Figure 4. Isopach map ..................................................................... 10


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SUMMARY

This report is a geoarchaeological assessment of strata

sampled in eight evaluation trenches excavated by

machine at Waterloo Wharf, Uxbridge.

Gravels of the Late Devensian Colney Street Gravel

Member subcropped in all the trenches between c.30.64m

OD and c.29.67m OD. In two trenches and one borehole

the Colney Street Gravel Member was overlain by a black

organic mud facies of possible Late-Glacial to Early

Holocene date and indicative of a back swamp

environment. This stratum is suggested to be broadly

coeval with similar deposits at Three Ways Wharf and

Riverside Way. In three trenches and three out of four

boreholes beside the Grand Union Canal, fine grained

alluvial silt/clays unconformably overlay the gravels and

represent overbank flood plain deposits of unknown date.

Modern made ground sealed the stratigraphic sequence.

.


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1. INTRODUCTION

1.1 In October 2015, at the request of Cotswold Archaeology on

behalf of their client Premier Forest Estates Ltd, ARCA carried

out a geoarchaeological monitoring programme of archaeological

evaluation trenches at Waterloo Wharf, Waterloo Road, Uxbridge

in the London Borough of Hillingdon (henceforth ‘the site’). The

geoarchaeological monitoring was carried out to investigate in

more detail the nature of the sub surface deposits on the site

that had been identified by a borehole survey monitored by

ARCA in August 2015 (Watson 2015). The work was in advance

of an application to the London Borough of Hillingdon Council

for redevelopment as outlined in the Written Scheme of

Investigation (WSI) and approved by Greater London

Archaeological Advisory Service (GLAAS) (Cotswold Archaeology

2015).

1.2 This document assesses the stratigraphic sequence beneath the site. It is arranged as follows: first, a brief account is provided of the geographical, geological and methodological background; secondly, the trench lithostratigraphy is described in detail; thirdly, a brief comparison is made to the strata recorded at Three Ways Wharf; and finally, an assessment is made of the archaeological and palaeoenvironmental potential of the sampled deposits. A bibliography and appendices containing borehole stratigraphic logs complete the document.

1.3 The site is approximately 0.4ha in size (NGR TQ 0497 8376) and is located on the east bank of the Grand Union Canal. To the east runs Waterloo Road with the northern boundary defined by Rockhampton Road and the southern boundary occupied by a boatyard and dry dock. The site lies within the valley of the River Colne, a major tributary of the Thames, rising in the Chilterns, and confluent with the Thames at Staines. It is situated towards the eastern edge of the present floodplain, which is traversed by a network of channels, both natural and artificial. The general ground level is c.31.50m OD.

1.4 The British Geological Survey (BGS) map the site as lying on

superficial deposits of unlithified alluvial silt and clay laid down

in the early Holocene (BGS 2015). The underlying bedrock is the

London Clay Formation that dates to the Eocene epoch 56 to

33.9 million years BP. To the east are deposits of the Langley

Silt Member, a Devensian (the last glacial stage in the Late

Pleistocene) periglacial loess otherwise known as brickearth. To

the west lie deposits of the Shepperton Gravel Member, a

Devensian terrace gravel. At higher elevations and several


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kilometres away from the site to the east and west are earlier

gravel terraces that developed in the Middle Pleistocene. Gravels

immediately underlying the present floodplain of the Colne in

the vicinity of the site are referred to as the Colney Street Gravel

Member, dated to the Late Devensian (Gibbard 1985, 81-2).

1.5 The site is within the Colne Valley Archaeological Priority Zone

and has been identified for its potential for Palaeolithic and

Mesolithic archaeology. The nationally significant site of Three

Ways Wharf (Lewis and Rackham 2011) is located c.800m north

where Upper Palaeolithic and Mesolithic lithic and faunal

remains were recovered. Recently, work at the former

Sandersons’ factory, now redeveloped as part of the Uxbridge

Business Park and one kilometre north of the site, was

undertaken by MoLAS and Cotswold Archaeology (MoLAS 2002

and 2006, Stastney 2015). Trenching and geoarchaeological

boreholes uncovered a deep sequence of alluvial deposits

including peat and tufa related to river channels in existence

during the Late Pleistocene to Early Holocene period. This suite

of alluvial strata is directly analogous to and apparently broadly

contemporary with Late-Glacial and Early Holocene strata

associated with Three Ways Wharf.

1.6 At Three Ways Wharf, in situ lithic and faunal scatters were

encountered within fine-grained mineral strata overlying the

Colney Street Gravel Member which in turn were sealed by a

sequence of black humic clay, tufa, and fine-grained mineral

alluvial strata (Lewis and Rackham 2011). Preservation of

palaeoenvironmental proxy indicators at Three Ways Wharf was

generally poor; however more recent investigations at the former

William King Flour Mill, immediately northwest of Three Ways

Wharf have demonstrated the potential to derive high-quality

multi-proxy palaeoenvironmental data from similar and broadly

contemporary sedimentary sequences (Grant et al. 2014). A

geoarchaeological borehole assessment at Plot A Uxbridge

Business Park in 2014 proved the case again with the recovery

of organic strata assessed as being of high palaeoenvironmental

potential (Stastney 2015).

1.7 Closer to the site at Waterloo Wharf archaeological investigation

has shown that the exceptional preservation of artefacts and

ecofacts seen at sites further north has not yet been found.

Work at Bansfield Allotments, c.300m northeast, recorded the

truncation of fine grained alluvial deposits over the river gravel;

and at 145 Waterloo Road made ground overlies the gravel

(CgMs 2007 cited in Cotswold 2015, p.5). On the other hand


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Riverside Way, c.200m west, preserves an Early Holocene

alluvial sequence overlying the Pleistocene gravels of grey silt

clay, black organic clay, peat and tufa; there was no evidence of

human activity though (Stafford 2015). Mesolithic activity has

been recorded at Denham 0.8km northwest of the site (Wessex

Archaeology 2009 p.8, 18) located on brickearth deposits in

which the modern soil had developed. Here the gravels underlay

the brickearth at 0.38m BGL. At Cowley Mill Road the gravels

were recorded at 1.2m BGL (29.60m OD) (Hood 2012).

1.8 The aims and objectives of the monitoring program are

discussed in full in the WSI p.6 (Cotswold Archaeology 2015). In

summary, they are to assess the potential of the archaeological

and palaeoenvironmental strata encountered in the Holocene

sedimentary sequence, and to sample for ecofacts and artefacts

where necessary, thereby improving our understanding of any

human activity on the site.

1.9 The evaluation trenches enabled a closer and more detailed

examination of the in situ strata to be made than was possible

during the borehole survey (Watson 2015). As a result some

conclusions drawn from the borehole evidence have been shown

to be in error and these are remarked upon in the text.

Otherwise mention will be made of the results of the borehole

survey where pertinent.

2. METHODOLOGY

2.1 Eight evaluation trenches were positioned within the site by

archaeologists of Cotswold Archaeology. The position of the

trenches had to respect the day to day use of the Goldberg’s

timber yard; as a result they were placed around the

circumference of the site avoiding the warehouse that occupies

the greater area at the centre: three north to south along the

metalled east bank of the Grand Union Canal and five north to

south parallel to Waterloo Road (Figure 1). Positioning of the

trenches was further complicated by underground services and

Trench 4 was abandoned as a consequence.

2.2 The trenches were excavated by machine. Sediments exposed

were photographed and described on site using standard

geological criteria (Tucker 2011; Jones et al. 1999; Munsell

Color 2000).


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Figure 1. Site plan. Canal section: south to north T1, WS05, WS03, T2, T3 LCP01. Waterloo Road section: south to north T9, T8, WS04, T7, WS02, T6, T5, WS01. Evaluation trenches are marked in blue and green and boreholes in black. (Plan courtesy of Cotswold Archaeology).

2.3 Trench locations were surveyed to Ordnance Survey NGR and

Ordnance Datum by hand and using GPS by Cotswold

Archaeology.

2.4 Lithological descriptions were combined with positional

information within a RockWorks database (RockWare 2013).

The RockWorks software was then used to plot the cross

sections presented in Figures 2 and 3. A higher level ranking of

lithological units into formal and informal stratigraphic

members and formations (Modern Made Ground, Alluvium,

Colney Street Gravel Member and London Clay Formation) was

assigned to the data and an isopach map produced using the

Kriging algorithm (Figure 4). This isopach map displays equal

thicknesses of a unit that are represented by bands of the same

colour (True Stratigraphic Thickness map). The thicknesses are

measured perpendicular to the boundaries of the unit. In this

case, the unit is a composite of three lithologies – Made Ground,

Alluvium and Organic Mud – chosen to delineate the sub


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surface topography of the Colney Street Gravel Member, the

geological basis over which human occupation has taken place.

2.5 The archive from the site consists of digital records:

photographs of the cores, RockWorks database entries and

lithological descriptions, which are stored at the University of

Winchester. One 0.1 x 0.1 x 0.2m monolith sample from Trench

6 is retained in the ARCA laboratory at the University of

Winchester.

3. EVALUATION TRENCH STRATIGRAPHY

3.0.1 Four major stratigraphic units (formal and informal formations

and members) were distinguished at the site. These are reviewed

below in chronological order (see Figures 2 and 3).

3.1 Colney Street Gravel Member.

3.1.1 Coarse, sandy flint gravels of the Colney Street Gravel Member

were encountered in all the trenches.

3.1.2 In the southeast corner of the site the Colney Street Gravel

Member subcrops at c.30.64m OD in Trench 8 and is

comparable to similar elevations of neighbouring boreholes and

trenches: c.30.30m OD in borehole LCP02 and c.30.55m OD in

Trench 9 (Figure 2). It dips gently north to where it subcrops at

c.29.70m OD in Trench 5 the northernmost trench, where it is

also comparable to a similar elevation of c.29.67m OD in the

neighbouring borehole WS01 (Figure 2). This is a maximum fall

in elevation of c.1m over 60m. There is a slight deviation of this

trend recorded in Trench 3 in the northwest where the gravels

rise and subcrop at c.30.45m OD (Figure 3).


8

Figure 2. Waterloo Road section south to north. Vertical exaggeration

x5


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Figure 3. Canal section south to north. Vertical exaggeration x5.

3.1.3 The stratum is a dark yellowish brown (10 YR 4/6) poorly

sorted, clast supported gravel. The clasts are sub rounded to

angular greyish black and ochre flint that range in size from

coarse sand size to cobble (0.5->64mm). The top c.0.3 m is often

coloured dark grey or black (5 Y 2.5/1) as a result of

penetration of humic acids from overlying reduced alluvium

and/or organic muds. The sand-sized fraction is fine to coarse

quartz and flint grains (field observation). Overlying fine-grained

alluvium appears to have penetrated the top of the open,

skeletal gravels.

3.2 Alluvium.

3.2.1 The Colney Street Gravel Member was unconformably overlain

(i.e. there was an erosive sharp boundary) by fine-grained

minerogenic alluvial sediment in Trenches 1, 2 and 3 (Figure 3).

On the basis of a more detailed examination of the Trench

sections the lithology of the neighbouring boreholes (WS05,

WS03 and LCP01) has been revised and concurs with that of the

Trenches.

3.2.2 The Alluvium was dark greenish grey (5 Y 4/1) with frequent

broad yellowish brown mottles (10 YR 4/3 and 5 Y 4/3). It was

homogenous and structureless and had no clastic content. No in

situ artefactual evidence could be found to confirm the

erroneous belief formed during the borehole survey that this


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unit was modern and the result of upcast from the construction

of the Grand Union Canal. Nor was any evidence found of

laminations within the clay tentatively recorded previously in

borehole WS03.

Figure 4. Isopach map

3.2.3 The unit varies little in thickness with an average of c.0.82m

and is confined, except for one instance in borehole WS02, to

the west border of the site along the Grand Union Canal. The

wall of the Canal appeared to have been set against the face of a

construction trench (revetted by a wooden stake in one trench)

cut through the in situ Alluvium.

3.2.4 The presence of Alluvium in borehole WS02 to the east implies

that this unit could well be expected below the footprint of the

warehouses that occupy the centre of the site (Figures 1 and 2).

Otherwise, its general absence to the east is in greater part due

to its complete truncation by modern Made Ground, and in

lesser part (if at all) by the rising elevation of the gravel to the

southeast.


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3.2.5 Figure 4 depicts the rise in elevation of the Colney Street Gravel

Member in the southeast of the site. It implies that any fine

grained alluvium, both organic and minerogenic, would lie over

deeper elevations in the area coloured green through to red.

3.2.6 The Alluvium was truncated and overlain by modern Made

Ground in all the trenches in which it occurred.

3.3 Organic Mud

3.3.1 Organic mud was recorded in Trenches 5 and 6 and in borehole

WS01 (Figure 2). It was confined to the north of the site. The

unit was c.0.15m thick (c.29.65m OD in Trench 5 and c.29.80m

OD in WS01) and coloured black (5 Y 2.5/1). Its stratigraphic

position was within the top of the Colney Street Gravel Member

and as a result the unit was a matrix supported gravel of coarse

sand to fine pebble-sized, sub angular black and ochre coloured

flints. In borehole WS01 the Organic Mud sampled was clast

free and c.0.1m thick suggesting that it overlay the gravel at

least in part, a fact not recorded in either of the trenches. The

matrix of Organic Mud contained occasional granular-sized (2-

4mm) plant fibres generally horizontally laid and very

occasionally clumped together. Rare granular-sized grey bivalve

shells were present too. The valves were separated and

frequently fragmented.

3.3.2 The stratigraphic relationship between the Organic Mud and the

Alluvium is unknown as they were not concurrent in any

trench. This is in contrast to the conclusion drawn in the

borehole survey (Watson 2015) where in borehole WS03 there

was slight evidence for alluvium overlying organic mud. Since

this occurrence was not found in Trench 2 positioned beside the

WS03, the relationship in the borehole is discounted here as

erroneous. Furthermore, no Organic Mud was recorded in the

trench.

3.3.3 The Organic Mud was overlain by modern Made Ground.

3.4 Made Ground

3.4.1 ‘Made Ground’ is a term used by the British Geological Survey

to encompass deposits formed as a product of human action

(BGS 2015). In this report all deposits that contained evidence

of modern human action have been grouped together under this

designation.


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3.4.2 The Made Ground includes heterogeneous strata often in poorly

defined lenses, that contained fragments of ceramic building

material primarily red or yellowish red brick and mortar (a

section of in situ walling was recorded in Trench 6) (Figures 2

and 3). The deposits were minerogenic. The fine grained

component was dark brown clay that was often mottled by iron

oxide staining as a result of a fluctuating water table. The

clastic component was flint and rarely chalk, present from

granule to cobble size, charcoal grains, fine pebble-sized (4-

8mm) slag, coal and glass fragments. Pebble-sized sherds of

white porcelain were present too. The Made Ground is believed

to date to the modern period (19th century) and truncates the

underlying alluvium but appears to respect the surface of the

Colney Street Gravel member. To the south east of the site the

Made Ground was heavily bioturbated by root and earthworm

action and the brown silt/clay deposits conserved some

granular structure that suggested a topsoil component (Trench

9).

4. ASSESSMENT

4.1 Late Quaternary sedimentary sequence.

4.1.1 The Late Quaternary sedimentary sequence at the site began

with the deposition of the Colney Street Gravel Member on the

braid plain of the precursor to the modern River Colne during

the Late Devensian stage of the Pleistocene.

4.1.2 After the end of the Late-Glacial period and quite possibly with a

hiatus in sedimentation, over bank flooding laid down fine-

grained minerogenic Alluvium to a depth of at least 0.9m.

Further away from the active channel, Organic Mud strata

developed most probably within a wet fen/reedswamp

environment; although it was not possible to identify

characteristic plant remains such as Cyperaceae (sedge family)

or Phragmites (reed). Freshwater bivalves were, however,

present.

4.1.3 The relationship between the Organic Mud and the minerogenic

silt/clay Alluvium is unknown, although it is possible that they

are the same lithofacies with organic sediments developing in

suitable microenvironments to be buried later by flood lain

fines.


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4.1.4 There was no evidence of tufa and only ephemeral evidence for

peat, nor was there any evidence of Early Holocene human

action. Modern human action though was responsible for the

truncation of the earlier strata and the deposition of

heterogeneous and artefact rich made ground.

4.2 Comparison with Three Ways Wharf and Riverside Way.

4.2.1 At Scatter A at Three Ways Wharf, orange clay (SU30) is

described as infiltrating the top of the gravels and overlying

them. This is overlain by a grey clay (SU40), itself sealed by

black organic clay (SU50). The sequence is approximately 0.5m

thick (Lewis and Rackham 2011, p.10). At Waterloo Wharf this

same sequence is not evident. There is no evidence for orange

clays infiltrated in the top of the gravels nor any overlying grey

clay. These clay deposits, intervening between the gravels and

the organic stratum, may have been truncated at Waterloo

Wharf, or not deposited because of topographical obstacles or

even incorporated into the organic stratum itself. Their absence

could also imply that the organic stratum at Waterloo Wharf

developed at a greater distance from the stream channel than

that seen at Three Ways Wharf; the intervening clays having

thinned out.

4.2.2 The surface of the black organic clay SU50 at Three Ways Wharf

lies at 31.3m OD (Lewis and Rackham 2011, p.10) and in

Trench 6 the organic mud is at c.30m OD (slightly lower in

WS01 and Trench 5). This is a downstream difference of c.1.3m

over one kilometre. The lower most organic silt recorded at

Riverside Way (about 200m west) subcrops at 29.30m OD and is

overlain by 0.28m of silty peat and black organic clays. These

deposits are all sufficiently similar in lithology and subcrop at a

similar elevation to suggest that they may be coeval and part of

the same lithofacies.

4.2.3 At Waterloo Wharf no direct relationship can be made between

the Alluvium that is characteristic of the west of the site and is

parallel to the Canal, and the Organic Mud stratum

characterising the north of the site (see section 4.1.3).

4.3 Archaeological and palaeoenvironmental potential.

4.3.1 The Colney Street Gravel Member at the site is of LOW to

MODERATE archaeological potential given the likely late


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Devensian date of the strata and their formation on a high-

energy braid plain. Human activity on such a plain is unlikely.

There is, however, some potential for the recovery of Final Upper

Palaeolithic lithic and faunal scatters from the upper surface of

gravels where these strata have stabilised and are overlain by

fine-grained strata.

4.3.2 The Colney Street Gravel Member is assessed as being of LOW

to MODERATE palaeoenvironmental potential. Fine-grained

beds which may contain palaeoenvironmental indicators do

occur within such strata but none were identified at the site.

4.3.3 The fine-grained minerogenic alluvial stratum – the Alluvium –

recovered from Trenches 1, 2, 3 and boreholes WS05, WS03,

LCP01 and WS02 is assessed as being of LOW to MODERATE

archaeological potential as flood plains have been environments

of human occupation in the past.

4.3.4 The Alluvium is assessed as being of LOW palaeoenvironmental

potential. Palaeoenvironmental indicators may be variably

preserved in such clastic sediments, however, the source of

microbiological remains may be difficult to determine (i.e. the

particles are allochthonous).

4.3.5 The Organic Mud stratum recovered from WS01, and Trenches

5 and 6 is assessed as being of LOW to MODERATE

archaeological potential. These strata formed in a back swamp

environment in which human activity would likely have been

sporadic at most; stray finds are a possibility though.

4.3.6 The Organic Mud stratum has a HIGH palaeoenvironmental

potential as palaeoenvironmental indicators are likely to be well-

preserved (macroscopic biological remains were noted).

4.3.7 The Made Ground strata recorded in all the trenches is modern

and has NO palaeoenvironmental potential nor premodern

archaeological potential.

5 ACKNOWLEDGEMENTS

5.1 ARCA would like to thank Simon Carlyle and Ralph Brown of

Cotswold Archaeology and Eleanor Standley of the University of

Oxford for their help during this phase of the project.


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6. BIBLIOGRAPHY

BGS (2015) British Geological Survey lexicon of named rock units. http://www.bgs.ac.uk/lexicon/ (Accessed 19 August 2015).

Cotswold Archaeology (2015) Waterloo Wharf Uxbridge London Borough Of Hillingdon: Written Scheme of Investigation for a Geoarchaeological Monitoring Exercise. Unpublished document. CA Project 660572. Cotswold Archaeology, Milton Keynes

Gibbard, P.L. (1985) The Pleistocene History of the Middle Thames Valley. Cambridge University Press, Cambridge.

Grant, M.J., Stevens, C.J., Whitehouse, N.J., Norcott, D., Macphail, R.I., Langdon, C., Cameron, N., Barnett, C., Langdon, P.G., Crowder, J., Mulhall, N., Attree, K., Leivers, M., Greatorex, R., Ellis, C. (2014) ‘A palaeoenvironmental context for Terminal Upper Palaeolithic and Mesolithic activity in the Colne Valley: Offsite records contemporary with occupation at Three Ways Wharf, Uxbridge’. Environmental Archaeology 19 (2): 131-152.

Hood, A. (2012) Land South of Cowley Mill Road, Uxbridge: Archaeological Evaluation. Unpublished report. Foundations Archaeology

Jones, A.P., Tucker, M.E. and Hart, J.K. (1999) ‘Guidelines and

recommendations’. In Jones, A.P., Tucker, M.E. and Hart, J.K.

(Eds.) The description and analysis of Quaternary stratigraphic

field sections. Quaternary Research Association technical guide

7, London, 27-76.

Lewis, J.S.C. and Rackham, J. (2011) Three Ways Wharf, Uxbridge: A

Lateglacial and Early Holocene hunter-gatherer site in the Colne

valley. MOLA Monograph 51. Museum of London Archaeology,

London.

Makaske, B. (2001) ‘Anastomosing rivers: a review of their

classification, origin and sedimentary products’. Earth Science

Reviews 53, 149-196.

MoLAS (2002) The former Sanderson site, Oxford Road, Denham: an

archaeological evaluation report. Unpublished report, MoLAS,

London.

MoLAS (2006) The former Sanderson site, Oxford Road, Denham UB9:

An archaeological post-excavation assessment and updated

project design. Unpublished report, MoLAS, London.

Munsell Color (2000) Munsell soil color charts. Munsell Color, New

Windsor (NY).


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Stafford, Elizabeth (2015) Phase 500 Riverside Way Uxbridge. Client

Report. Unpublished.

Trevarthan, M and Manning, A (2009) Preferred Area 4, Denham,

Buckinghamshire. Unpublished Report, Wessex Archaeology

Tucker, M.E. (2011) Sedimentary rocks in the field. Wiley, Chichester.

Watson, N. M. (2015) Waterloo Wharf, Uxbridge: geoarchaeological

monitoring of boreholes. Unpublished ARCA Report 1516-3.

University of Winchester.


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APPENDIX 1: EVALUATION TRENCH LOGS

Location Depth below ground

level (from/to)

Type Description

Trench 1

0.00 0.30 Made ground Concrete and sub base.

0.30 1.14 Silt/clay 5 Y 4/1 Dark grey with frequent mottles of 10

YR 4/3 Dark yellowish brown and 5 Y 4/3

Olive compact silt/clay. Structure less.

(Alluvium). Sharp boundary to:

1.14 1.38 Flint gravel 5 Y 4/2 Olive grey poorly sorted, clast

supported flint gravel. Angular to sub-rounded

black and ochre coloured flints. Silt/clay

matrix with frequent coarse-sand-sized

mineral grains (flint and quartz). Becoming 10

YR 4/4 Dark yellowish brown.

Trench 2




Olive compact silt/clay. Structureless.



supported flint gravel. Angular to sub-rounded



mineral grains (flint and quartz).


18


level (from/to)

Type Description

Trench 3




Olive compact silt/clay. Structureless.



supported flint gravel. Angular to sub-

rounded black and ochre coloured flints.

Silt/clay matrix with frequent coarse-sand-

sized mineral grains (flint and quartz).

Becoming 10 YR 4/4 Dark yellowish brown

with depth.

Trench 5


0.36 1.45 Made ground 10 YR 5/4 yellowish brown stiff silt/clay

mixed with 10 YR 4/1 Dark grey silt/clay with

granular to pebble-sized fragments of brick,

sub angular flint, slag, cbm, chalk and

charcoal in interdigitating lenses and layers.

Lens of chalk. (Modern Made ground). Sharp

boundary to:


19


level (from/to)

Type Description

Trench 5

1.45 1.60 Organic mud 5 Y 2.5/1 Black matrix supported gravel of

coarse sand to fine pebble-sized, sub angular

black and ochre coloured flints. Matrix of

organic mud with rare to occasional granular-

sized plant fibres. Rare granular-sized bivalve

shells, separated and frequently fragmented.

1.60 1.80 Flint gravel 5 Y 2.1/1 Black poorly sorted, clast supported

flint gravel. Black humic acids infiltrating top

of gravel deposit. Angular to sub-rounded




Trench 6

0.00 1.40 Made ground Modern made ground: Tarmac and concrete

sealing laid brick and mortar wall over coarse

diamict of reworked ?London Clay and

fragmented bricks. Sharp boundary to:

1.40 1.55 Organic mud 5 Y 2.5/1 Black matrix supported gravel of

coarse sand to fine pebble-sized, sub angular

black and ochre coloured flints. Matrix of

organic mud with rare to occasional granular-

sized plant fibres. Rare granular-sized bivalve

shell, separated and frequently fragmented.

Small monolith sample taken. CA take 10l+

samples.


20


level (from/to)

Type Description

Trench 6 1.55 1.75 Flint gravel 5 Y 2.5/1 Black poorly sorted, clast supported

flint gravel. Black humic acids infiltrating top

of gravel deposit. Angular to sub-rounded




Trench 7

0.00 0.32 Made ground Concrete and black diamict (charcoal and coal)

sub base.

0.32 0.52 Made ground 10 YR 4/3 Brown diamict of brick fragments.

(Modern Made Ground). Sharp boundary to:

0.52 1.22 Made ground 10 YR 3/1 Very dark grey silt/clay with

frequent granular to fine pebble-sized flint,

cbm (white porcelain), slag and mortar.

Occasional granules of charcoal. Bioturbated

by roots. (Modern Made Ground). Sharp

boundary to:

1.22 1.42 Flint gravel 10 YR 3/3 Dark brown and 10 YR 4/4 Dark

yellowish brown poorly sorted, clast supported

flint gravel. Angular to sub-rounded black

and ochre coloured flints. Silt/clay matrix with

frequent coarse sand-sized mineral grains

(flint and quartz).


21


level (from/to)

Type Description

Trench 8


0.30 0.80 Made ground 10 YR 3/1 Very dark grey friable and

heterogeneous diamict of frequent granular to

coarse pebble-sized clasts of brick and flint

and frequent granular to fine pebble-sized

charcoal, coal, glass and slag. Heavily

bioturbated by roots and earthworms. (Modern

Made Ground). Sharp boundary to:

0.80 1.00 Flint gravel 10 YR 3/3 Dark brown and 10 YR 4/4 Dark





(flint and quartz). Some bioturbation by roots.

Trench 9


0.30 0.95 Made ground 10 YR 3/1 Very dark grey heterogeneous

diamict of occasional granular to coarse

pebble-sized clasts of brick and flint and

occasional granular to fine pebble-sized

charcoal, coal, and slag. Porcelain fragment.

Some granular crumb structure. Heavily

bioturbated by roots and earthworms.

(?Agricultural soil. Modern Made Ground).

Sharp boundary to:


22


level (from/to)

Type Description

Trench 9 0.95 1.15 Flint gravel 10 YR 3/3 Dark brown and 10 YR 4/4 Dark





(flint and quartz). Some bioturbation by roots.

Documents

WATERLOO WHARF UXBRIDGE, PHASE II: GEOARCHAEOLOGICAL ... · London Clay Formation that dates to the Eocene epoch 56 to 33.9 million years BP. To the east are deposits of the Langley