Land at North West Malmesbury Wiltshire
Heritage Assessment
for Persimmon Homes (Wessex) Ltd
CA Project: 5201 CA Report: 14569
January 2016
Land at North West Malmesbury Wiltshire
Heritage Assessment
CA Project: 5201 CA Report: 14569
prepared by Dr David Kenyon, Heritage Consultant; Rosey Meara, Heritage Consultant
date January 2016
checked by Richard Morton, Principal Heritage Consultant
date January 2016
approved by Richard Morton, Principal Heritage Consultant
signed
date January 2016
issue 01
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.
© Cotswold Archaeology Cirencester Milton Keynes Andover Building 11 Unit 4 Office 49 Kemble Enterprise Park Cromwell Business Centre Basepoint Business Centre Kemble, Cirencester Howard Way, Newport Pagnell Caxton Close, Andover Gloucestershire, GL7 6BQ MK16 9QS Hampshire, SP10 3FG t. 01285 771022 t. 01908 218320 t. 01264 326549 f. 01285 771033 e. [email protected] © Cotswold Archaeology Land at NW Malmesbury: Heritage Assessment
CONTENTS
SUMMARY ...... 1
1. INTRODUCTION ...... 2
2. METHODOLOGY ...... 3
3. PLANNING POLICY CONTEXT ...... 4
4. OVERVIEW OF THE HERITAGE RESOURCE AND A SUMMARY OF THE DEVELOPMENT HISTORY OF THE SITE AND ITS WIDER ENVIRONS ...... 7
5. CONCLUSIONS ...... 15
6. REFERENCES ...... 18
APPENDIX A: GAZETTEER OF RECORDED HERITAGE ASSETS AND OTHER ELEMENTS OF THE HISTORIC ENVIRONMENT ...... 20
APPENDIX B EXTRACTS FROM NORTH WILTSHIRE LOCAL PLAN 2011 ...... 22
APPENDIX C: THE HEDGEROWS REGULATIONS 1997 ...... 23
APPENDIX D: JANUARY 2015 GEOPHYSICAL SURVEY ...... 24
LIST OF ILLUSTRATIONS
Figure 1 Site location plan Figure 2 Recorded heritage assets Figure 3 Geophysical survey results and adjacent previous archaeological works Figure 4 Extract from the 1840 Tithe Map of Brokenborough, Charlton and Westport Figure 5 Extract from 1886 First Edition Ordnance Survey map
© Cotswold Archaeology Land at NW Malmesbury: Heritage Assessment
SUMMARY
Project Name: Land at North West Malmesbury, Wiltshire NGR: ST 9270 8115 Type: Heritage Assessment
Cotswold Archaeology was commissioned by Persimmon Homes (Wessex) Ltd to update a heritage desk-based assessment of land to the north-west of Malmesbury, Wiltshire. Geophysical survey was also commissioned, the results of which are included wihtin this report. The objective of the assessment is to identify the nature and significance of any heritage assets within the site and its wider environs.
Geophysical survey has recorded anomalies which most likely represent below-ground remains associated with Romano-British settlement within the western area of the site. Current evidence does not indicate that these remains are of the highest significance, i.e. of a commensurate value to Scheduled Monuments, but they may have the potential to contribute to Regional Research Aims, identified in the South West Regional Research Framework. Appropriate mitigation measures will be required to manage the identified resource appropriately.
An appropriate archaeological strategy will be devised in consultation with Wiltshire Council Archaeological Service. This will be informed by the present Heritage Statement and may include the use of further evaluative archaeological techniques at appropriate stages of the planning process in order to provide a proportionate level of information on the archaeological remains within the site, and to ensure an appropriate mitigation strategy is put in place.
No designated heritage assets lie within the site or its immediate vicinity. Designated heritage assets within the wider study area comprise Listed buildings within the historic core of Malmesbury Conservation Area, 400m southeast of the site. These buildings lie within a built up urban area, with further development lying between them and the site. The site does not form a significant part of the setting of these buildings, and does not contribute significantly to their overall heritage value. Thus the ‘setting’ of Listed buildings in the vicinity would be preserved in accordance with the ‘special regard’ required by the Planning (Listed Buildings and Conservation Areas) Act 1990 (s66), as would the character and appearance of the conservation area (s72).
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1. INTRODUCTION
Background 1.1 Cotswold Archaeology was commissioned by Persimmon Homes (Wessex) Ltd to update a heritage desk-based assessment of land north of Malmesbury (centred on ST 9270 8115; Fig. 1). A desk-based assessment had originally been compiled in 2012. Geophysical survey was also commissioned, the results of which are incorporated into this report. The objective of the assessment is to identify the nature and significance of any heritage assets within the site and its wider environs.
Location and landscape context 1.2 The site is located on the northern outskirts of the town of Malmesbury, Wiltshire, lying south-west of the B4014 Tetbury Road. The site is bounded to the south-west by a branch of the river Avon (Fig. 1). The site lies within the modern parish of Malmesbury.
1.3 The site is situated across agricultural fields, currently under pasture, separated by hedges. The site occupies an area of land between the large Dyson factory (to the north) and the River Avon, which forms the southern site boundary. The proposed access road runs west and then north from the site across the approved Dyson Tetbury Hill development site (Wiltshire Council Ref. 14\02971\OUT).
Scope 1.4 The assessment focuses upon the heritage resource of the proposed development site although a minimum 500m ‘buffer’ around the site has also been assessed in detail, referred to as the ‘Study Area’ (Fig. 2).
1.5 The aims of this assessment are to: identify designated heritage assets present within the proposed development site and the Study Area;
gather information on non-designated recorded heritage assets;
determine the potential for currently unrecorded buried archaeological remains on the proposed development site, using professional expertise to assess the evidence base; and
provide an overview of the significance of these heritage assets.
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1.6 Geophysical survey was undertaken in January and February 2015. The associated report is included as Appendix D, and the results are summarised within this Heritage Assessment.
2. METHODOLOGY
2.1 The assessment methodology is based on guidance provided by the Institute for Archaeologists ‘Standards and Guidance for Historic Environment Desk-based Assessment’ (CIfA 2014).
2.2 The assessment considered a Study Area comprising the proposed development site itself, and a 500m ‘buffer’ around the site. The size of this study area ensured that historic mapping and data sources provide sufficient information about the proposed development site and its surrounding landscape from which to assess known and potential impacts on the heritage resource. This in turn provided a clearer indication of the proposed development site’s history, context and archaeological potential. All known heritage assets identified within this radius, and close to the perimeter of this study area, have been considered in this assessment.
2.3 Historic environment data was utilised from the Historic England Archive (formerly the National Monuments Record) and the Wiltshire and Swindon Historic Environment Record (HER). This comprised data on designated heritage assets such as Scheduled Monuments and Listed buildings, non-designated assets comprising archaeological find-spots, sites, investigations, historic buildings, cartographic and other documentary records.
2.4 In addition the following resources were consulted and documents studied: Historic maps, documents and other sources available at the Wiltshire and Swindon History Centre;
The Multi-Agency Geographic Information for the Countryside (MAGIC) website for designated heritage assets comprising Scheduled Monuments, Registered Battlefields, Registered Parks and Gardens of Special Historic Interest and World Heritage Sites;
Wiltshire County Council Planning web pages for information of regional and local planning policy documentation;
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Historic aerial photographs, studied at the English Heritage Archive in Swindon, to identify known and potential archaeological sites and evidence of historic land disturbance within the site boundary; and
British Geological Survey online Geology of Britain Viewer.
2.5 Site visits were undertaken on 3 January 2013 and 14 January 2015 to understand the context and relationship of the heritage assets under consideration and to better understand the potential constraints, if any, to the proposed development.
2.6 Known heritage assets within the Study Area and those designated assets outside it considered of sufficient significance for inclusion are reported in Section 4. A gazetteer of known and potential heritage assets in the study area has been compiled (Appendix A). All assets are referred to in the text by a unique reference number 1, etc. The locations of these assets can be seen on Fig. 2.
2.7 This Heritage Assessment incorporates the results of geophysical survey commissioned at the site. The full report, including a detailed description of the methodology, is included within Appendix D.
3. PLANNING POLICY CONTEXT
Planning policy and guidance context 3.1 The assessment has been written within the following legislative, planning policy and guidance context: The Historic Buildings and Ancient Monuments Act (1953) National Heritage Act 1983 (amended 2002), Town and Country Planning Act (1990) Planning (Listed Buildings and Conservation Areas) Act (1990) English Heritage Conservation Principles: policies and guidance for the sustainable management of the historic environment (2008) The Setting of Heritage Assets: English Heritage Guidance (2011) National Planning Policy Framework (2012) National Planning Practice Guidance: Conserving and enhancing the historic environment (2014)
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Planning (Listed Buildings and Conservation Areas) Act (1990)
3.2 In determining planning applications that might affect the settings of Listed Buildings the 1990 Act states that:
‘In considering whether to grant planning permission for development which affects a listed building or its setting, the local planning authority or, as the case may be, the Secretary of State shall have special regard to the desirability of preserving the building or its setting or any features of special architectural or historic interest which it possesses.’ (Part I, Chapter VI, Section 66).
‘In the exercise, with respect to any building or other land in a conservation area, of any powers under any of the provisions mentioned in subsection (2), special attention shall be paid to the desirability of preserving or enhancing the character or appearance of that area.’ (Part I, Chapter VI, Section 72).
National Planning Policy Framework (NPPF) 3.3 The NPPF sets out national planning policy relating to the conservation and enhancement of the historic environment. It defines the historic environment as ‘all aspects of the environment resulting from the interaction between people and places through time, including all surviving physical remains of past human activity, whether visible, buried or submerged, and landscaped and planted or managed flora.’
3.4 Individual aspects of the historic environment are considered heritage assets: ‘buildings, monuments, sites, places, areas or landscapes identified as having a degree of significance meriting consideration in planning decisions, because of their heritage interest.’
3.5 Heritage assets include designated sites and non-designated sites, and policies within the NPPF relate to both the treatment of assets themselves and of their settings, both of which are a material consideration in development decision making.
3.6 Key tenets of the NPPF are that: when considering the impact of a proposed development on the significance of a designated heritage asset, great weight should be given
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to the asset’s conservation. The more important the asset, the greater the weight should be; significance can be harmed or lost through alteration or destruction of the heritage asset or development within its setting. As heritage assets are irreplaceable, any harm or loss should require clear and convincing justification. Substantial harm to, or loss of, a Grade II listed building, park or garden should be exceptional. Substantial harm to or loss of designated heritage assets of the highest significance, notably scheduled monuments, protected wreck sites, battlefields, Grade I and II* listed buildings, Grade I and II* registered parks and gardens, and World Heritage Sites, should be wholly exceptional (paragraph 132); where a proposed development will lead to less than substantial harm to the significance of a designated heritage asset, this harm should be weighed against the public benefits of the proposal (paragraph 134); and with regard to non-designated heritage assets, a balanced judgement will be required having due regard to the scale of any harm or loss, and to the significance of the heritage asset affected (paragraph 135).
3.7 Local planning authorities are urged to request applicants to describe the significance of any heritage assets affected by a proposed development, including any contribution made by their setting. The level of detail required in the assessment should be ‘proportionate to the assets’ importance, and no more than is sufficient to understand the potential impact of the proposal on their significance.’
Local planning policy 3.8 The current Local Development Plan for Wiltshire comprises the Wiltshire Core Strategy Development Plan Document, adopted in January 2015, which has replaced the relevant policies of the former West Wiltshire District Plan (June 2004). Core Policy 58 pertains to heritage and is provided in Appendix B.
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4. OVERVIEW OF THE HERITAGE RESOURCE AND A SUMMARY OF THE DEVELOPMENT HISTORY OF THE SITE AND ITS WIDER ENVIRONS
Introduction
4.1 This section provides an overview of the historical and archaeological background of the study area and the region surrounding it in order to provide a better understanding of the context and significance of the heritage resource that may be affected by the proposed development. This assessment then determines the significance of any affected heritage assets (Section 5 of this report) and the potential for encountering buried archaeological remains within the proposed site boundary and predicts their likely nature, extent and condition.
Summary of statutory and non-statutory designated heritage assets 4.2 No World Heritage Sites, or sites included on the Tentative List of Future Nominations for World Heritage Sites (July 2010) are situated within the site or its vicinity.
4.3 There are no Scheduled Monuments located within the site or study area. The nearest Scheduled Monument is Malmesbury Abbey (SAM number: 19043) located approximately 600m to the south-east of the site (not illustrated). Malmesbury town centre is designated as a Conservation Area, and the northern limit of this area falls within the southern portion of the study area (Fig. 2, 1); however it does not extend near the development site itself.
4.4 A number of buildings Listed at Grade II or II* are present within the wider study area. These all lie within the Conservation Area in the northern part of Malmesbury town (Fig. 2, 1) and are not individually marked on Fig. 2.
4.5 There are no Registered Parks or Gardens or Registered Battlefields recorded within the site or the study area.
4.6 The North Wiltshire Local Plan 2011 defined a series of ‘Areas of Special Archaeological Significance’ where the survival of significant archaeological deposits is either demonstrated or considered likely, and thus where proposed development should be subject to greater scrutiny. The site does not lie within an Area of Special Archaeological Significance. The River Avon (Sherston-Malmesbury) Area of
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Special Archaeological Significance is located on the western edge of the study area, adjacent to the western part of the site (Fig. 2) and comprises a c. 15sq. km area of largely arable land. The designated area includes a large cluster of cropmark sites around the Roman town south-east of Easton Grey; the Saxon town of Malmesbury; and the medieval village earthworks to the north of the site at Brokenborough.
Summary of non-designated or potential heritage assets 4.7 Archaeological works associated with development of the Dyson Tetbury Hill site (Wiltshire Council Ref. 14\02971\OUT) included geophysical survey across the northern part of the site and the adjacent area (Fig. 2 2; Fig. 3; Stratascan 2014). The geophysical survey identified a group of linear anomalies adjacent to the current proposed development site (Fig. 3). Subsequent trial trench evaluation identified ditches with Romano-British (2nd-3rd-century AD) activity (Fig. 2, 2; Fig. 3; CA 2014). Planning permission for development at the Dyson Tetbury Hill site was granted, conditional on a programme of archaeological work comprising aerial earthwork survey of ridge and furrow and archaeological excavation targeted on the Romano-British features (CA forthcoming).
4.8 Geophysical survey in 2015 (Fig. 3; Stratascan 2015, reproduced in full in Appendix D), associated with the current proposed development, recorded a complex of anomalies, including probable enclosures and pits, within the western area of the site. These are adjacent to the Romano-British ditches recorded in the trial trench evaluation at the Dyson Tetbury Hill site. The anomalies identified in the 2015 survey most likely represent the remains of Romano-British settlement. Similar features may continue to the south/west, beyond the current site.
4.9 Extant ridge and furrow earthworks are present in the north-eastern area of the site (Fig. 2). Geophysical survey (Stratascan 2015, reproduced in full in Appendix D) has identified anomalies consistent with the below-ground remains of furrows in the central and south-eastern areas of the site.
4.10 Hedgerows within the site are depicted on the 1840 Tithe map and may therefore be considered as ‘Important’ under the Regulations 1997 (criteria for archaeology and history, see Appendix C).
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Previous investigations 4.11 Previous archaeological work associated with the Dyson Tetbury Hill site has been undertaken within and adjacent to the northern area of the current site (Fig. 2, 2; Fig. 3). This included geophysical survey which extended into the northern area of the current site. This was followed by trial trench evaluation adjacent to the current site. These works recorded Romano-British ditches potentially associated with settlement activity (Fig. 2, 2a; Fig. 3).
4.12 A programme of field walking and geophysical survey prior to the construction of a gas pipeline was undertaken in 2001, which encompassed a linear transect across the northern part of the study area (Fig. 2, 3; Network Archaeology 2001). A series of pits and other features were identified in the geophysical survey in the fields c. 300m to the north-west of the site. Concentrations of medieval pottery were also identified during field walking of this area.
4.13 Geophysical survey in the north-eastern part of the study area in 2014 recorded anomalies of probable archaeological origin including probable pits and ditches (Fig. 2, 4). Subsequent trial trench evaluation recorded prehistoric ditches (publication forthcoming; Wiltshire and Swindon Historic Environment Record, pers. comm.).
4.14 Archaeological works within Malmesbury Conservation Area (Fig. 2, 1), in the south- eastern part of the study area, which recorded medieval and post-medieval features.
Geology, topography and the palaeoenvironment 4.15 The solid geology within the site is mapped as Kellaways Clay member mudstone, Conbrash Formation limestone and Forest Marble Formation mudstone. A tributary of the River Avon forms the southern boundary of the site (Fig. 2). The BGS records alluvium adjacent to the course of the river, comprising superficial deposits of clay, silt, sand and gravel formed up to 2 million years ago in the Quaternary Period. At this time the local environment would previously have been dominated by rivers, and the alluvium was formed from rivers depositing mainly sand and gravel detrital material in channels to form river terrace deposits, with fine silt and clay from overbank floods forming floodplain alluvium. There is some possibility for organic material of some palaeoenvironmental interest within former courses of the river within this southern part of the site.
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4.16 Terrace deposits of sand and gravel lie immediately to the north and west of the Dyson factory, on the very north-eastern edge of the site. These superficial terrace deposits were also formed in the Quaternary Period. They are not of closely defined origin, and could be river gravels, fluvioglacial outwash spreads, or a combination of these with elements with reworking including solifluction.
4.17 The highest point of the site is on its northern edge, at a height of approximately 90m aOD (above Ordnance Datum), the remainder slopes south-west to the river Avon, falling to a height of approximately 70m aOD.
Prehistoric (pre – AD 43) 4.18 Prehistoric activity is known from the wider locality of the site and recent excavations have shown that the modern town of Malmesbury (1.7km to the south of the site) is located on the site of an Iron Age hillfort (BARAS 2002), set on the high ground overlooking the confluence of the Tetbury and Sherston branches of the Bristol Avon.
4.19 Although there are no confirmed prehistoric features from within the site or study area, cropmarks have been recorded in the fields to the east of the site, suggesting the presence of prehistoric features. Analysis of aerial photographs suggests at least two possible ring ditches are present in the field adjacent to the northern end of the site (Fig. 2, 5). A series of possible enclosures and linear features has also been recorded in the same area. These cropmarks have previously been interpreted as Bronze Age round barrows, medieval windmill sites and medieval field systems. However, the most recent aerial photographs of the cropmarks (ST 9288/ 9- 25; July 2006) demonstrate a degree of intercutting between the ring ditch features, suggesting with the evidence of possible enclosure ditches, that together they represent a prehistoric settlement complex with several phases of prehistoric round houses. Further undated cropmarks were also identified to the south east of the site, possibly representing drainage ditches (Fig. 2, 6), however these have now been covered by recent residential development.
Roman (AD 43 – c. AD 410) 4.20 Geophysical survey in 2014 for the adjacent approved site (through which the access road for the present site passes) recorded a small group of linear anomalies (Fig. 2, 2; Fig. 3; Stratascan 2014). Subsequent trial trench evaluation (Fig. 2, 2; Fig.
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3; CA 2014) recorded four ditches of Romano-British date (2nd 3rd-century AD). Two of these ditches potentially formed the north-eastern and south-eastern edges of an enclosure. A concentration of pottery and burnt crop-processing waste was indicative of nearby settlement. The results of targeted archaeological excavation at this location are forthcoming (CA forthcoming).
4.21 Geophysical survey undertaken January 2015 (Fig. 3; Stratascan 2015, report reproduced in full in Appendix D) recorded a concentration of magnetic anomalies immediately south of those identified in 2014. Again, this is to the west of the main site area, in the land through which the access road passes. The recorded features include possible enclosures, ditches and pits. These most likely represent remains associated with Romano-British rural settlement, contemporary with the ditches identified to the north. Only a limited number of small magnetic anomalies were identified in the main site of the present application, which may possibly represent pits or non-archaeological features and generally less well-defined (Fig. 3). Little evidence for field enclosures was found in the main site area. If any remains were undetected by the geophysics it is most likely that they would relate to former field enclosures outlying the settlement.
4.22 The fieldwork evidence thus provides good evidence for a small Roman rural settlement to the west of the current site, partially beneath the access road. The evidence indicates that the settlement lay outside of the main site area, and no domestic settlement remains would be expected within it. Small Romano-British rural settlements are not uncommon in the archaeological record. However, investigation of sites of this type can potentially contribute to Regional Research Aim 29, Improve understanding of non-villa Roman rural settlement (Webster 2007, Grove and Croft 2012). Investigation of 2nd-3rd century Roman contexts is identified in the Action Plan as a future research topic associated with Research Aim 10, Address lack of understanding of key transitional periods (Grove and Croft 2012, table 6.1).
4.23 In the wider landscape, an extensive Roman settlement has been recorded by geophysical survey 1.5km east of the site (not illustrated) and cropmark sites have been recorded around a Roman town south-east of Easton Grey, 4.5km south-west of the site. The Fosse Way passes approximately 2.3km to the west of the site and linked the large Roman settlements of Bath (Aquae Sulis) and Cirencester (Corinium). A possible hypocaust has been recorded from the town centre of
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Malmesbury (750m south-east of the site) which may relate to a Roman building. The findspot of a Roman coin is recorded c. 500m south-east of the site (Fig. 2, 7).
Early medieval (AD 410 - 1066) and medieval periods (1066 – 1539) 4.24 Malmesbury was founded as a religious school in the late 7th century, and is first recorded as Mealdumesburg in AD 675 (Haslam 1976, 35). The town went on to become a Saxon burh and borough town, surrounded by a defensive earth bank. The core of the Saxon town is situated approximately 800m to the south-east of the site (WCAS 2004), and the site itself is likely to have formed part of Malmesbury’s agricultural hinterland, on the northern banks of the Tetbury branch of the River Avon. In the early medieval period the majority of the land around the town belonged to Malmesbury Abbey. The site itself lies in the historic parish of Westport, and it is likely that this separate settlement and parish was established at an early (possibly Saxon) date (VCH 1991, 229).
4.25 The settlement of Brokenborough to the northwest of the site has also been identified as Saxon in origin. It was known as Brokene Beregge in AD 956, and a number of earthworks and cropmarks have been recorded associated with this early settlement (Fig. 2, 8).
4.26 The site is located adjacent to what is now known as Tetbury Hill, the road leading northwards out of the town in the direction of Tetbury (6km north-west of the site). The road is likely to have followed the course of an earlier routeway between Tetbury (first mentioned in AD681) and Malmesbury, and is likely to have been in use during the early medieval period.
Ridge and furrow earthworks 4.27 Evidence of medieval or early post-medieval agricultural activity within the site and its environs is present in the form of ridge and furrow cultivation earthworks. ‘Ridge and furrow’ is a broad term for undulating earthworks comprising a series of higher ‘ridges’ separated by lower ‘furrows’. They can occur in different forms, and may date to the medieval, post-medieval or modern periods. The earliest medieval type was created over time through ploughing with oxen teams (plough horses were introduced from around the thirteenth century), the plough always turning the soil to the right and gradually pushing up central ridges at intervals of around 8m. Oxen teams required a wide turning circle, which led to a distinctive long reverse ‘S’- shaped layout of the earthworks (Rackham 1986, 168). Ridge and furrow also
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originated at later dates, when it is typically narrower (around 4m or so), longer and set out in straight lines, and may have originated through different causes, including cart-ruts and, most commonly, improvements to irrigation and drainage.
4.28 Areas of ridge and furrow earthworks have been identified on aerial photographs within a small part of the northern area of the site and across the wider study area. Areas of extant ridge and furrow within and in the immediate vicinity of the site are shown on Fig. 2. These are concentrated on the higher ground in the northern area of the site and survive up to a height of 0.3m from furrow-base to ridge-top. The width and alignment of these earthworks suggests that they may be of medieval origin. To the west of the site, a small area of parallel banks or lynchets, also likely to comprise ridge and furrow, survives up to 1m in height (Fig. 2, 10).
4.29 Geophysical survey within the site in 2015 recorded further evidence for below- ground remains of furrows within the central and south-eastern areas of the site (Appendix D).
4.30 Evidence of medieval and early post-medieval agricultural activity was also identified during fieldwalking prior to the construction of a gas pipeline on the northern edge of the site. A concentration of medieval and early post-medieval pottery sherds, likely to have been deposited during manuring of fields was recovered from the field immediately to the north of the site. Several undated pits were also identified during geophysical survey in the same area (Network Archaeology 2001, 13; Fig. 2, 3).
Post-medieval (1540 – 1800) and modern periods (1801 – present) 4.31 The site is likely to have remained part of the agricultural hinterland of Malmesbury and its satellite settlements throughout the post-medieval period. The site appears to have remained relatively unchanged throughout this period, unaffected by surrounding events such as Malmesbury’s involvement in the Civil War.
4.32 The earliest detailed cartographic representation of the site is on the Andrews and Drury map of Wiltshire from 1773 (not illustrated). No detail of hedgerows or field boundaries are included on this map but relief is shown with high ground to the north-east of the site. Buildings are shown adjacent to Back Bridge, west of the site, on this source (Fig. 2, 12). No buildings are recorded within the site.
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4.33 The site is also depicted on the Tithe map of Brokenborough and Westport parishes dating from 1840 (Fig. 4). A number of field boundaries are depicted on this map corresponding with the surviving hedgerows on the site. Where surviving hedgerows can be dated to 1845 or earlier they are considered to be historically ‘Important’ in accordance with the criteria of The Hedgerows Regulations 1997 (Appendix C). ‘Important’ hedgerows are not designated heritage assets (as defined in NPPF Annex 2) although they do retain some heritage significance as components of a wider historic landscape element. The Hedgerow Regulations are essentially a notification mechanism. Thus an applicant needs to notify the LPA prior to the removal, either entirely or in part, of an ‘important’ hedgerow. No field names of interest are detailed in the accompanying Apportionment Registered, which records a predominantly pastoral use for the site area, with some arable.
4.34 The First Edition Ordnance Survey map of 1889 (Fig. 5) shows a very similar arrangement to that on the Tithe map. The 19th-century Backbridge Farm is depicted to the north-east of the site, and two ponds are shown in the field immediately to the west of the farm. This includes the pond which is extant within the northern part of the site. A mortuary chapel had been constructed c. 130m east of the site. A series of trackways are depicted to the east of the site, including one which extended into the eastern field. This area is recorded as ‘Allotment Gardens’ on later mapping (Third Edition Ordnance Survey map, see below) and the trackways are most likely associated with this. A north-south bank was observed in this location during the site visit (Fig. 5).
4.35 Later editions of the Ordnance survey map show a very similar situation over much of the site. The south-eastern field is labelled as ‘Liable to Floods’ on the Second Edition Ordnance Survey map of 1900 (not reproduced). In the wider area, a ‘Fever’ or ‘Isolation Hospital’, built on the hill slope a short distance to the north-west of the cottage at Back Bridge, west of the site (Fig. 2, 23). This was an isolation ward serving Malmesbury Hospital, and was in use from the late 1890s until 1933 (VCH 1991, 235) but no information concerning its detailed character has been identified. The south-eastern site boundary had been defined by the time of the Third Edition Ordnance Survey map of 1924 (not illustrated).
The wider study area 4.36 Farm buildings, including farmsteads are recorded across the study area, identified on the historic maps and recorded on the Wiltshire and Swindon Historic
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Environment Record (Fig. 2, 12-22, 30). In addition, a number of World War Two defence features are recorded within the wider study area, including two pillboxes (Fig. 2, 26 and 27), a search light battery (Fig. 2, 24), an anti-tank ditch (Fig. 2, 25), and a spigot Mortar Emplacement (Fig. 2, 28). These features were constructed in 1940 as part of anti-invasion defences protecting the port of Bristol. They form part of ‘Stop Line Green’ which ran from Highbridge on the Bristol Channel to Upper Framilode on the River Severn. The defences utilised the line of the river Avon south of Malmesbury before passing to the east of the town and on northwards through the eastern edge of the study Area (Green 1999, 1). The anti-tank ditch was rapidly filled in after the war but is still visible as a slight spoil bank along its former line.
4.37 Since 1945 the most significant change to the landscape around the site has been development along Tetbury Hill. In particular, the construction of the Dyson Factory immediately to the east of the site led to the demolition of Backbridge Farm.
Factors affecting the survival of any buried archaeological remains 4.38 Impacts upon potential buried archaeological remains within the site derive chiefly from prevailing agricultural practices over the centuries. Predominantly these impacts would have occurred through ploughing, both medieval furrows and modern deep ploughing.
5. CONCLUSIONS
Heritage significance 5.1 Geophysical survey has identified a concentration of anomalies which most likely represent the below-ground remains associated with Romano-British settlement to the west of the main site area, partially under the access road. Adjacent trial trench evaluation identified ditches dated to the 2nd to 3rd-century AD and contemporary remains most likely survive within the current site. Investigation of these below- ground remains could contribute to Research Aims identified in the South West Regional Research Framework, including Regional Research Aim 29, Improve understanding of non-villa Roman rural settlement (Webster 2007, Grove and Croft 2012). Investigation of 2nd-3rd century Roman contexts is identified in the associated Action Plan as a future research topic associated with Research Aim 10,
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Address lack of understanding of key transitional periods (Grove and Croft 2012, table 6.1).
5.2 The English Heritage publication ‘Settlement Sites to 1500’ (EH 2013) notes a number of factors that contribute to significance, including period; rarity and representation; documentation; group value; survival and condition; diversity; archaeological potential; and landscape placement and notes that evaluation of significance should be undertaken on a case by case basis. Small Romano-British rural settlements are not uncommon in the archaeological record and remains of this type are not generally considered to be of the highest significance. The geophysical survey results do not indicate remains of potentially national significance (i.e. of Schedulable quality) in this settlement area, such as would require preservation in situ. Appropriate mitigation measures as part of an archaeological strategy will be agreed with Wiltshire Council Archaeological Service (see paragraph 5.8 below).
5.3 The geophysical survey has not identified evidence for any significant archaeological remains within the main site area. Remains of early agricultural practice in the form of earthwork ridge-and-furrow cultivation survive within the northernmost part, and in adjacent fields. Such remains form a common feature of the local agricultural landscape and comprise heritage assets of limited heritage significance (comprising limited historic, evidential and aesthetic values). Below-ground remains of furrows identified by geophysical survey within the site are not of sufficient heritage value to comprise heritage assets.
5.4 Hedgerows within the site which are present along boundaries shown on the 1840 Tithe map are considered to be historically ‘Important’ in accordance with the criteria of The Hedgerows Regulations 1997 (Appendix C). It should be noted that ‘Important’ hedgerows are not designated heritage assets (as defined in NPPF Annex 2) and that the Regulations are essentially a mechanism requiring notification to the Council prior to any removal of qualifying hedgerows. These hedgerows are considered to be heritage assets of limited heritage value.
Potential development effects and national and development plan policy 5.5 No designated heritage assets lie within the site. The only designated heritage assets within the wider study area comprise Listed buildings within the historic core of Malmesbury Conservation Area, some 400m southeast of the site. These buildings lie within a built up urban area, with further development lying between
16 © Cotswold Archaeology Land at NW Malmesbury: Heritage Assessment
them and the site. The site does not form a significant part of the setting of these buildings, and does not contribute significantly to their overall heritage value. Thus development within the site would not be anticipated to adversely affect their setting or heritage value. Thus the ‘setting’ of Listed buildings in the vicinity would be preserved in accordance with the ‘special regard’ required by the Planning (Listed Buildings and Conservation Areas) Act 1990 (s66), as would the character and appearance of the conservation area (s72). As no harm (including no substantial harm) would be occasioned to designated heritage assets, or assets of commensurate value, then development permission need not be ‘exceptional’ and paragraph 133 of the Framework would not be engaged.
5.6 Current evidence does not indicate that below-ground archaeological remains are of sufficient significance to warrant designation, and are thus very unlikely to be of ‘demonstrably of equivalent significance to scheduled monuments’ as set out in Paragraph 139 of the Framework. Paragraph 135 of the Framework states that when weighing applications that affect non-designated heritage assets ‘a balanced judgement will be required having regard to the scale of any harm or loss of significance of the heritage asset’.
5.7 Development plan policy pertaining to archaeological remains is reproduced in Appendix B of this report. Policy HE5 notes that ‘there will be a presumption in favour of the physical preservation in situ of nationally important archaeological remains and their settings, whether the site is scheduled or not’. As noted, there is no evidence that remains of this value are situated within the site. Policy HE6 notes that ‘satisfactory measures are taken to ensure the physical preservation of any archaeological remains in situ; or In cases where the significance of any archaeological remains is outweighed by the need for and benefits of the development, satisfactory measures are taken to excavate and record the site and its remains’.
17 © Cotswold Archaeology Land at NW Malmesbury: Heritage Assessment
6. REFERENCES
Bristol and Region Archaeological Services (BARAS), 2002, Post-Excavation Assessment Report of the Excavation at St Joseph’s Primary School, Malmesbury
BGS (British Geological Survey), 2011, Geology of Britain Viewer. Online resource at http://maps.bgs.ac.uk/geologyviewer_google/googleviewer.html, viewed January 2013
CA (Cotswold Archaeology) 2014 Land at Tetbury Hill, Malmesbury: archaeological evaluation, CA typescript report 14085
CA (Cotswold Archaeology) forthcoming Tetbury Hill, Malmesbury: archaeological excavation and earthwork survey
English Heritage 2008, Conservation Principles: Policies and Guidance for the Sustainable Management of the Historic Environment
English Heritage 2013 Designation Scheduling Selection Guide: Settlement Sites to 1500, pdf report available online at www.english-heritage.org.uk
Green, M, 1999, Warwalks Stop Line Green (Reardon Publishing, Cheltenham)
Haslam, J., 1976, Wiltshire Towns: The Archaeological Potential
Institute for Archaeologists, 2011, Standard and Guidance for Archaeological Desk- Based Assessment
Grove, J. and Croft, B. 2012 (eds.) The Archaeology of South West England: South West Archaeological Research Framework: Research Strategy 2012-2017, Somerset County Council, pdf version available at www1.somerset.gov.uk
Network Archaeology, 2001, Easton Grey to Minety Proposed Gas Pipeline, Archaeological Fieldwalking and Field Reconnaissance (Network Archaeology Unpub Report)
18 © Cotswold Archaeology Land at NW Malmesbury: Heritage Assessment
Stratascan 2014 Geophysical Survey Report: Tetbury Hill, Malmesbury, typescript report ref. J6167
Webster, C.J. (ed.) 2007 The Archaeology of South West England: South West Archaeological Research Framework: Resource Assessment and Research Agenda, Somerset County Council, pdf version available online at www1.somerset.gov.uk
Victoria County History (VCH), 1991, Victoria History of Wiltshire: Vol. XIV: Malmesbury Hundred (Oxford Univ. Press)
Wiltshire Council Archaeology Service (WCAS), 2004, The Archaeology of Wiltshire’s Towns: An Extensive Urban Survey: Malmesbury
Cartographic Sources 1773 A Map of Wiltshire taken from an Actual Survey (Andrews and Drury)
1840 Map of the Parishes of Charlton, Brokenborough and Westport St Mary in the County of Wilts (Tithe Map)
1889 First Edition Ordnance Survey 6’’ Map Sheet: 8
1900 Second Edition Ordnance Survey 25’’ map Sheet: 8.10
1921 Provisional Edition Ordnance Survey 25’’ map Sheet: 8.10
1980 Ordnance Survey 1:2500 map (Sheet ST9288)
19 9 92 9 94 2 4
9900
8888
8866
STST N 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 Land at North West Malmesbury Wiltshire Wiltshire
FIGURE TITLE Site location plan 0 1km
FIGURE NO. Reproduced from the 2006 Ordnance Survey Explorer map with DRAWN BY AO/LJH PROJECT NO. 5201 the permission of Ordnance Survey on behalf of The Controller CHECKED BY JB DATE 02/06/2016 of Her Majesty's Stationery Office c Crown copyright Cotswold Archaeology Ltd 100002109 APPROVED BY RM SCALE@A4 1:25,000 1 994 992 993 991 4 3 1 2 N
24 8 26
site
25 study area prehistoric 8899 Romano-British
27 medieval 5 8 post-medieval/modern previous archaeological works 9 Conservation Area 22 3a 2 Area of Special Archaeological Significance surviving ridge and furrow cropmarks on aerial photographs
10 2a 13 4 23
12
21 11
20 6 30
8888 19 17
18
15 28 16 14 0 500m 29 1 01:10,000 500m
Reproduced from the 2006 Ordnance Survey Explorer map with the permission of Ordnance Survey on behalf of The Controller of Her Majesty's Stationery Office c Crown copyright Cotswold Archaeology Ltd 100002109
Andover 01264 347630 Cirencester 01285 771022 7 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 w www.cotswoldarchaeology.co.uk e [email protected]
PROJECT TITLE Land at North West Malmesbury Wiltshire
FIGURE TITLE Recorded heritage assets
8877 DRAWN BY AO/LJH PROJECT NO. 5201 FIGURE NO. CHECKED BY JB DATE 02/06/2016 STST APPROVED BY RM SCALE@A3 1:10,000 2 9 925 9 930 2 3 ST 5 0
B4014
888585 Factory
Tetbury Hill
Tetbury Hill Gardens
Park Road River Avon 888080
Malmesbury Primary School
N Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 site boundary area of 2015 w www.cotswoldarchaeology.co.uk geophysical survey e [email protected] area of 2014 geophysical survey geophysical survey anomaly PROJECT TITLE Land at North West Malmesbury (after Stratascan 2015): geophysical survey anomaly Wiltshire
(after Stratascan 2014) probable archaeology FIGURE TITLE Geophysical survey result and adjacent trial trench (CA 2014) possible archaeology previous archaeological works
FIGURE NO. 01:5,000 250m DRAWN BY AO/LJH PROJECT NO. 5201 Reproduced from the 2005 Ordnance Survey Explorer map with the permission CHECKED BY JB DATE 02/06/2016 of Ordnance Survey on behalf of The Controller of Her Majesty's Stationery Office c Crown copyright Cotswold Archaeology Ltd 100002109 APPROVED BY RM SCALE@A3 1:5000 3 4
Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 4 Extract from the 1840 Tithe Map of Brokenborough w www.cotswoldarchaeology.co.uk Charlton and Westport e [email protected] PROJECT TITLE Land at North West Malmesbury Wiltshire
FIGURE TITLE Historic map
DRAWN BY AO/LJH PROJECT NO. 5201 FIGURE NO. CHECKED BY JB DATE 02/06/2016 APPROVED BY RM SCALE@A4 1:10,000 4 5
Andover 01264 347630 Cirencester 01285 771022 Cotswold Exeter 01392 826185 Archaeology Milton Keynes 01908 564660 5 Extract from the 1840 First Edition Ordnance Survey w www.cotswoldarchaeology.co.uk map of 1886 e [email protected] PROJECT TITLE Land at North West Malmesbury Wiltshire
FIGURE TITLE Historic map
DRAWN BY AO/LJH PROJECT NO. 5201 FIGURE NO. CHECKED BY JB DATE 02/06/2016 APPROVED BY RM SCALE@A4 1:10,000 5 © Cotswold Archaeology Land at NW Malmesbury: Heritage Assessment
APPENDIX A: GAZETTEER OF RECORDED HERITAGE ASSETS AND OTHER ELEMENTS OF THE HISTORIC ENVIRONMENT
No. Description Period NGR HER ref. (all ST) AMIE ref. other 1 Malmesbury Conservation Area. - Includes: Encompasses the historic core of Malmesbury. MWI3668 Includes Grade I, II and II* Listed buildings. MWI5409 Early medieval and later settlement. MWI5415 Archaeological works within the area of the EWI6604 Conservation Area within the study area MWI64337 recorded medieval and later finds/features. MWI 64300 1485688 2 2014 geophysical survey and trial trench Roman 9257 8860 MWI64296 evaluation, Tetbury Hill. MWI64297 Roman features EWI7509 EWI7386 3 2001 Fieldwalking and geophysical survey: Medieval 9250 8890 EWI5941 Easton Grey to Minety Proposed Gas Pipeline. Undated MWI31407 Pottery recovered in fieldwalking. Possible pit MWI31407 clusters recorded by geophysical survey. 4 2014 geophysical survey, Malmesbury. Undated 9345 8852 EWI7604 Anomalies of probable archaeological origin MWI64298 including pits and ditches. 5 Cropmarks visible in air photographs Undated 9287 8878 MW15422 Possible barrows or windmill mounds MWI72625 Field boundaries 518967
6 Cropmarks visible in air photographs Undated/ 9320 8810 MW15431 Prehist?
7 Findspot: Roman coin; Medieval spindle whorl Roman 9297 8743 MWI5349 Medieval MWI5380 8 Saxon settlement Brokenborough Early 9180 8820 MW15378 Medieval MW15364
9 Possible holloway Medieval 9316 8892 MWI31408 10 Lynchet earthworks Med/ Post 9225 8841 MW15432 Med?
11 Ridge and furrow earthworks Medieval/ 9118 8764 MWI72663 Post- MWI72632 medieval 1519038 1519043 12 Back Bridge cottage C18th? 9230 8830 1773 Map
13 Backbridge Farm house (site of) C19th 9265 8840 OS Maps 1889,1900 MWI66247 14 Site of farmstead Modern 9290 8774 MWI66221 15 Site of farmstead Modern 9285 8780 MWI66222 16 Site of outfarm Modern 9263 8777 MWI71319 17 Site of outfarm Modern 9251 8801 MWI71318 18 Site of outfarm Modern 9244 8787 MWI66231 19 Park Lane Farm Modern 9210 8802 MWI71320 20 Charters Mead Farm Modern 9215 8812 MWI71321 21 Outfarm south-east of Boakley Cliff Modern 9202 8821 MWI66152 22 Site of farmstead Modern 9314 8871 MWI66248 23 Isolation hospital (site of) Modern 92220 8835 OS Maps 1900, 1921 24 WW2 Searchlight battery (site of) Modern 9261 8934 1518935
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25 Ww2 Ant-tank ditch Modern 9311 8909 1518949 26 WW2 Pillbox (Type 29) Modern 9274 8930 1421308 27 WW2 Pillbox (Type 26) Modern 9318 8894 1421309 28 Spigot Mortar Emplacement Modern 9312 8769 MWI31878 1428123 29 Home guard headquarters Modern 9317 8780 MWI32004 1416468 30 Site of outfarm Modern 9190 8808 MWI66102
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APPENDIX B EXTRACTS FROM NORTH WILTSHIRE LOCAL PLAN 2011
‘Core Policy 58: Ensuring the conservation o the historic environment: Development should protect, conserve, and where possible enhance, the historic environment.
Designated heritage assets and their settings will be conserved, and where appropriate enhanced in a manner appropriate to their significance, including:
i. Nationally significant archaeological remains ii. World Heritage Sites within, and adjacent to, Wiltshire iii. Buildings and structures of special architectural or historic interest iv. The special character or appearance of Conservation Areas v. Historic parks and gardens vi. Important landscapes, including registered battlefields and townscapes.
Distinctive elements of Wiltshire’s historic environment, including non-designated heritage assets which contribute to a sense of local character and identity, will be conserved, and where possible enhanced. The potential contribution of these heritage assets towards wider social, cultural, economic and environmental benefits will also be utilised where this can be delivered in a sensitive and appropriate manner in accordance with Core Policy 57.
Heritage assets at risk will be monitored, and development proposals that improve their condition will be encouraged. The advice of statutory and local consultees will be sought in consideration of such applications.’
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APPENDIX C: THE HEDGEROWS REGULATIONS 1997
The 1997 Hedgerow Regulations were made under section 97 of the Environment Act 1995, and introduced arrangements for Local Planning Authorities to protect ‘important’ hedgerows in the countryside, by controlling their removal through a system of notification. The DEFRA publication ‘The Hedgerows Regulations 1997: A Guide to the Law and Good Practice’ is a useful guide in this respect. The Regulations provide criteria for assessing whether a hedgerow is ‘important’ for the purposes of the Regulations. To qualify as ‘important’ a hedgerow must have existed for 30 years or more and following this must fulfil at least one of the criteria in the Schedule 1 criteria. Those for ‘archaeology and history’ comprise Part II, namely:
1. The hedgerow marks the boundary, or part of the boundary, of at least one historic parish or township; and for this purpose “historic” means existing before 1850.
2. The hedgerow incorporates an archaeological feature which is- (a) included in the schedule of monuments compiled by the Secretary of State under section 1 (schedule of monuments) of the Ancient Monuments and Scheduled Areas Act 1979(g); or (b) recorded at the relevant date in a Sites and Monuments Record [Historic Environment Records have largely replaced Sites and Monuments Records].
3. The hedgerow- (a) is situated wholly or partly within an archaeological site included or recorded as mentioned in paragraph 2 or on land adjacent to and associated with such a site; and (b) is associated with any monument or feature on that site.
4. The hedgerow- (a) marks the boundary of a pre-1600 AD estate or manor recorded at the relevant date in a sites and Monuments Record or on a document held at that date at a Record Office; or (b) is visibly related to any building or feature of such an estate or manor.
5. The hedgerow- (a) is recorded in a document held at the relevant date at a Record Office as an integral part of a field system pre-dating the Inclosure acts(a); or (b) is part of, or visibly related to, any building or other feature associated with such a system, and that system- (i) is substantially complete; or (ii) is of a pattern which is recorded in a document prepared before the relevant date by a local planning authority, within the meaning of the 1990 Act(b), for the purposes of development control within the authority’s area, as a key landscape characteristic
The criterion of point five is the subject of debate and differing interpretation. Some heritage professionals interpret the criterion referring to the individual Inclosure Act for the parish in which a site is located, and numerous Acts were made in the 18th century (including the 1773 Inclosure Act). However, the criterion references the Short Titles Act of 1896, and it is commonly interpreted by LPAs and heritage professionals that it thus refers to the Inclosure Act of 1845, and subsequent Acts up to the Commonable Rights Compensation Act of 1882. This latter interpretation sets a date of 1845 as the benchmark test.
‘Important’ hedgerows are not designated heritage assets (as defined in NPPF Annex 2). The Regulations are essentially a notification mechanism. Thus an applicant needs to notify the LPA prior to the removal, either entirely or in part, of an ‘important’ hedgerow. There is a prescribed form of notice set out in Schedule 4 to the Regulations, although the form an LPA uses does not have to follow this. The requirement is for sufficient information to be given to the LPA for them to consider the proposed removal.
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APPENDIX D: JANUARY 2015 GEOPHYSICAL SURVEY
24
Project name: Land at North West Malmesbury, Wiltshire
Client: Cotswold Archaeology
February 2015
Job ref: J7816
Report author: Thomas Richardson MSc ACIfA
GEOPHYSICAL SURVEY REPORT
Project name: Land at North West Malmesbury, Wiltshire Client: Cotswold Archaeology
Job ref: Field team: J7816 Richard Collins BA (Hons), Lukasz Krawec BSc, Andrew Bateman BSc (Hons)
Techniques: Project manager: Detailed magnetic survey – Simon Haddrell BEng(Hons) AMBCS PCIfA Gradiometry
Survey date: Report written By: 12th-13th & 23rd January & Thomas Richardson MSc ACIfA 2nd February 2015
Site centred at: CAD illustrations by: ST 927 881 Thomas Richardson MSc ACIfA
Post code: Checked by: SN16 9JP David Elks MSc ACIfA
Geophysical Survey Report Project Name: Land at North West Malmesbury, Wiltshire Job ref: J7816 Client: Cotswold Archaeology Date: February 2015 ______
TABLE OF CONTENTS
LIST OF FIGURES...... 1 1 SUMMARY OF RESULTS ...... 2 2 INTRODUCTION ...... 2 2.1 Background synopsis ...... 2 2.2 Site location ...... 2 2.3 Description of site ...... 2 2.4 Geology and soils ...... 2 2.5 Site history and archaeological potential ...... 3 2.6 Survey objectives ...... 3 2.7 Survey methods ...... 3 2.8 Processing, presentation and interpretation of results ...... 3 2.8.1 Processing ...... 3
2.8.2 Presentation of results and interpretation ...... 4
3 RESULTS ...... 4 3.1 Probable Archaeology ...... 4 3.2 Possible Archaeology ...... 5 3.3 Other Anomalies ...... 5 4 CONCLUSION ...... 6 5 REFERENCES ...... 7 APPENDIX A – METHODOLOGY & SURVEY EQUIPMENT ...... 8 APPENDIX B – BASIC PRINCIPLES OF MAGNETIC SURVEY ...... 9 APPENDIX C – GLOSSARY OF MAGNETIC ANOMALIES ...... 10
LIST OF FIGURES
Figure 01 1:1250 Site location, survey area & referencing
Figure 02 1:1250 Colour plot of gradiometer data showing extreme values
Figure 03 1:1250 Plot of minimally processed gradiometer data
Figure 04 1:1250 Abstraction and interpretation of gradiometer anomalies
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1 SUMMARY OF RESULTS
A detailed gradiometry survey was conducted over approximately 13.2 hectares of grassland. The survey identified an area of settlement activity in the north west, whilst former field boundaries and ridge and furrow cultivation suggest that the area has been used for agricultural purposes since the medieval period. A number of possible archaeological anomalies have also been identified, however it is not possible to determine their origin with any degree of confidence. The remaining anomalies are of modern or natural origin. The modern anomalies relate to former field boundaries, underground services, agricultural activity, ferrous objects and fencing.
2 INTRODUCTION
2.1 Background synopsis Stratascan were commissioned to undertake a geophysical survey of an area outlined for development. This survey forms part of an archaeological investigation being undertaken by Cotswold Archaeology.
2.2 Site location The site is located to the west of Tetbury Hill, Malmesbury, Wiltshire at OS ref. ST 927 881.
2.3 Description of site The survey area is approximately 13.2 hectares of grassland. The area slopes from the north down to the south, with some small obstructions on the south eastern field caused by trees.
2.4 Geology and soils The underlying geology is Kellaways Clay Member – Mudstone in the north of the site, Forest Marble Formation – Mudstone in the south, with a band of Cornbrash Formation – Limestone between them (British Geological Survey website). There is no recorded drift geology across the majority of the site, with an area of Alluvium – Clay, Silt, Sand and Gravel running along the southern boundary (British Geological Survey website).
The overlying soils for the north of the site are known as Wickham 3, which are typical stagnogley soils. These consist of fine loamy over clayey and coarse loamy over clayey soils. The south of the site is covered by Sherborne soils, which are typical brown rendzinas. These consist of brashy calcareous clayey soils over limestone (Soil Survey of England and Wales, Sheet 5 South West England).
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2.5 Site history and archaeological potential Extract from ‘Land North of Malmesbury: Heritage Desk-Based Assessment’ (Cotswold Archaeology 2013):
Cropmarks recorded on aerial photographs suggest the presence of the below ground remains of a possible prehistoric settlement complex to the east of the site. There is some potential for currently unrecorded remains associated with prehistoric or Romano-British settlement or agriculture (such as field boundary systems) to lie within the site. Known archaeological sites elsewhere in the region indicate that the northern area of the site, on slightly higher ground overlooking the river valley, has more potential for any such remains.
A previous geophysical survey, immediately to the north of the current survey area, identified former field boundaries, ridge and furrow cultivation, and a number of archaeological linear anomalies (Stratascan 2014).
2.6 Survey objectives The objective of the survey was to locate any features of possible archaeological origin in order that they may be assessed prior to development.
2.7 Survey methods This report and all fieldwork have been conducted in accordance with both the English Heritage guidelines outlined in the document: Geophysical Survey in Archaeological Field Evaluation, 2008 and with the Institute for Archaeologists document Standard and Guidance for Archaeological Geophysical Survey.
Given the potential for prehistoric and Romano-British features, and a previously successful geophysical survey, detailed magnetic survey (gradiometry) was used as an efficient and effective method of locating a wide variety of archaeological anomalies. More information regarding this technique is included in Appendix A.
2.8 Processing, presentation and interpretation of results
2.8.1 Processing Processing is performed using specialist software. This can emphasise various aspects contained within the data but which are often not easily seen in the raw data. Basic processing of the magnetic data involves 'flattening' the background levels with respect to adjacent traverses and adjacent grids. Once the basic processing has flattened the background it is then possible to carry out further processing which may include low pass filtering to reduce 'noise' in the data and hence emphasise the archaeological or man-made anomalies.
The following schedule shows the basic processing carried out on all minimally processed gradiometer data used in this report:
1. Destripe (Removes striping effects caused by zero-point discrepancies between different sensors and walking directions)
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2. Destagger (Removes zigzag effects caused by inconsistent walking speeds on sloping, uneven or overgrown terrain)
2.8.2 Presentation of results and interpretation The presentation of the data for each site involves a print-out of the minimally processed data both as a greyscale plot and a colour plot showing extreme magnetic values. Magnetic anomalies have been identified and plotted onto the 'Abstraction and Interpretation of Anomalies' drawing for the site.
3 RESULTS
The detailed magnetic gradiometer survey conducted at Malmesbury has identified a number of anomalies that have been characterised as being either of a probable or possible archaeological origin.
The difference between probable and possible archaeological origin is a confidence rating. Features identified within the dataset that form recognisable archaeological patterns or seem to be related to a deliberate historical act have been interpreted as being of a probable archaeological origin.
Features of possible archaeological origin tend to be more amorphous anomalies which may have similar magnetic attributes in terms of strength or polarity but are difficult to classify as being archaeological or natural.
The following list of numbered anomalies refers to numerical labels on the interpretation plots.
3.1 Probable Archaeology
1 Positive linear and curvilinear anomalies in the north west of the site. These form a number of enclosures related to former settlement activity.
2 A number of small discrete positive anomalies in the north west of the site. These are indicative of backfilled pits, related to the settlement activity seen in Anomaly 1.
3-6 Linear anomalies across the site. These are likely to relate to former field boundaries not present on available mapping.
7 Areas of widely spaced curving parallel linear anomalies. These are indicative of ridge and furrow cultivation.
8 Linear anomalies either side of a former field boundary (Anomaly 9). These are likely to relate to post-medieval agricultural activity.
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9-10 Linear anomalies in the south east of the site. These are related to former field boundaries present on available mapping. Anomaly 9 is present 1840- 1889, whilst Anomaly 10 is present 1840-1975.
3.2 Possible Archaeology
11-16 Positive linear anomalies across the site. These are indicative of former cut features, and may be of archaeological or agricultural origin.
17 Small discrete positive anomalies across the site. These are indicative of small former cut features, such as backfilled pits, and may be of archaeological origin. However, the widespread nature of these anomalies would suggest a more natural origin.
3.3 Other Anomalies
18 A high amplitude linear anomaly in the east of the site. This is related to a former field boundary present on available mapping 1921-1983.
19 A high amplitude linear anomaly in the east of the site. This is likely to be a former footpath or field boundary continuing on from Anomaly 16, but not on available mapping.
20 Areas of closely spaced parallel linear anomalies across the site. These are indicative of modern agricultural activity, such as ploughing.
21 High amplitude bipolar linear anomalies in the north west of the site. These are indicative of underground services.
22 An area of magnetic variation in the north west of the site. This is likely to be of geological or pedological origin.
23 Areas of magnetic disturbance are the result of substantial nearby ferrous metal objects such as fences and underground services. These effects can mask weaker archaeological anomalies, but on this site have not affected a significant proportion of the area.
24 A number of magnetic ‘spikes’ (strong focussed values with associated antipolar response) indicate ferrous metal objects. These are likely to be modern rubbish.
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4 CONCLUSION
The survey at Malmesbury has identified a number of anomalies of probable and possible archaeological origin. An area of settlement activity can be seen in the north west, which corresponds with the view of the desk-based assessment that there is potential for prehistoric or Romano-British settlement. The former field boundaries and ridge and furrow cultivation suggest that the area has been used for agricultural purposes since the medieval period. A number of possible archaeological anomalies have also been identified, however it is not possible to determine their origin with any degree of confidence. The remaining anomalies are of modern or natural origin. The modern anomalies relate to former field boundaries, underground services, agricultural activity, ferrous objects and fencing.
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5 REFERENCES
British Geological Survey South Sheet, 1977. Geological Survey Ten Mile Map, South Sheet First Edition (Quaternary). Institute of Geological Sciences.
British Geological Survey, 2001. Geological Survey Ten Mile Map, South Sheet, Fourth Edition (Solid). British Geological Society.
British Geological Survey, n.d., website: (http://www.bgs.ac.uk/opengeoscience/home.html?Accordion1=1#maps) Geology of Britain viewer.
Cotswold Archaeology, 2013. Land North of Malmesbury: Heritage Desk-Based Assessment
English Heritage, 2008. Geophysical Survey in Archaeological Field Evaluation.
Institute For Archaeologists. Standard and Guidance for Archaeological Geophysical Survey. http://www.archaeologists.net/sites/default/files/nodefiles/Geophysics2010.pdf
Soil Survey of England and Wales, 1983. Soils of England and Wales, Sheet 5 South West England.
Stratascan, 2014. Geophysical Survey Report Tetbury Hill, Malmesbury, Wiltshire
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APPENDIX A – METHODOLOGY & SURVEY EQUIPMENT
Grid locations The location of the survey grids has been plotted together with the referencing information. Grids were set out using a Leica 705auto Total Station and referenced to suitable topographic features around the perimeter of the site or a Leica Smart Rover RTK GPS.
An RTK GPS (Real-time Kinematic Global Positioning System) can locate a point on the ground to a far greater accuracy than a standard GPS unit. A standard GPS suffers from errors created by satellite orbit errors, clock errors and atmospheric interference, resulting in an accuracy of 5m-10m. An RTK system uses a single base station receiver and a number of mobile units. The base station re-broadcasts the phase of the carrier it measured, and the mobile units compare their own phase measurements with those they received from the base station. A SmartNet RTK GPS uses Ordnance Survey’s network of over 100 fixed base stations to give an accuracy of around 0.01m.
Survey equipment and gradiometer configuration Although the changes in the magnetic field resulting from differing features in the soil are usually weak, changes as small as 0.2 nanoTeslas (nT) in an overall field strength of 48,000nT, can be accurately detected using an appropriate instrument.
The mapping of the anomaly in a systematic manner will allow an estimate of the type of material present beneath the surface. Strong magnetic anomalies will be generated by buried iron-based objects or by kilns or hearths. More subtle anomalies such as pits and ditches can be seen if they contain more humic material which is normally rich in magnetic iron oxides when compared with the subsoil.
To illustrate this point, the cutting and subsequent silting or backfilling of a ditch may result in a larger volume of weakly magnetic material being accumulated in the trench compared to the undisturbed subsoil. A weak magnetic anomaly should therefore appear in plan along the line of the ditch.
The magnetic survey was carried out using a dual sensor Grad601-2 Magnetic Gradiometer manufactured by Bartington Instruments Ltd. The instrument consists of two fluxgates very accurately aligned to nullify the effects of the Earth's magnetic field. Readings relate to the difference in localised magnetic anomalies compared with the general magnetic background. The Grad601-2 consists of two high stability fluxgate gradiometers suspended on a single frame. Each gradiometer has a 1m separation between the sensing elements so enhancing the response to weak anomalies.
Sampling interval Readings were taken at 0.25m centres along traverses 1m apart. This equates to 3600 sampling points in a full 30m x 30m grid.
Depth of scan and resolution The Grad 601-2 has a typical depth of penetration of 0.5m to 1.0m, though strongly magnetic objects may be visible at greater depths. The collection of data at 0.25m centres provides an optimum methodology for the task balancing cost and time with resolution.
Data capture The readings are logged consecutively into the data logger which in turn is daily down- loaded into a portable computer whilst on site. At the end of each site survey, data is transferred to the office for processing and presentation.
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Geophysical Survey Report Project Name: Land at North West Malmesbury, Wiltshire Job ref: J7816 Client: Cotswold Archaeology Date: February 2015 ______
APPENDIX B – BASIC PRINCIPLES OF MAGNETIC SURVEY
Detailed magnetic survey can be used to effectively define areas of past human activity by mapping spatial variation and contrast in the magnetic properties of soil, subsoil and bedrock.
Weakly magnetic iron minerals are always present within the soil and areas of enhancement relate to increases in magnetic susceptibility and permanently magnetised thermoremanent material.
Magnetic susceptibility relates to the induced magnetism of a material when in the presence of a magnetic field. This magnetism can be considered as effectively permanent as it exists within the Earth’s magnetic field. Magnetic susceptibility can become enhanced due to burning and complex biological or fermentation processes.
Thermoremanence is a permanent magnetism acquired by iron minerals that, after heating to a specific temperature known as the Curie Point, are effectively demagnetised followed by re-magnetisation by the Earth’s magnetic field on cooling. Thermoremanent archaeological features can include hearths and kilns and material such as brick and tile may be magnetised through the same process.
Silting and deliberate infilling of ditches and pits with magnetically enhanced soil creates a relative contrast against the much lower levels of magnetism within the subsoil into which the feature is cut. Systematic mapping of magnetic anomalies will produce linear and discrete areas of enhancement allowing assessment and characterisation of subsurface features. Material such as subsoil and non- magnetic bedrock used to create former earthworks and walls may be mapped as areas of lower enhancement compared to surrounding soils.
Magnetic survey is carried out using a fluxgate gradiometer which is a passive instrument consisting of two sensors mounted vertically 1m apart. The instrument is carried about 30cm above the ground surface and the top sensor measures the Earth’s magnetic field whilst the lower sensor measures the same field but is also more affected by any localised buried field. The difference between the two sensors will relate to the strength of a magnetic field created by a buried feature, if no field is present the difference will be close to zero as the magnetic field measured by both sensors will be the same.
Factors affecting the magnetic survey may include soil type, local geology, previous human activity, disturbance from modern services etc.
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Geophysical Survey Report Project Name: Land at North West Malmesbury, Wiltshire Job ref: J7816 Client: Cotswold Archaeology Date: February 2015 ______
APPENDIX C – GLOSSARY OF MAGNETIC ANOMALIES
Bipolar
A bipolar anomaly is one that is composed of both a positive response and a negative response. It can be made up of any number of positive responses and negative responses. For example a pipeline consisting of alternating positive and negative anomalies is said to be bipolar. See also dipolar which has only one area of each polarity. The interpretation of the anomaly will depend on the magnitude of the magnetic field strength. A weak response may be caused by a clay field drain while a strong response will probably be caused by a metallic service.
Dipolar
This consists of a single positive anomaly with an associated negative response. There should be no separation between the two polarities of response. These responses will be created by a single feature. The interpretation of the anomaly will depend on the magnitude of the magnetic measurements. A very strong anomaly is likely to be caused by a ferrous object.
Positive anomaly with associated negative response
See bipolar and dipolar.
Positive linear
A linear response which is entirely positive in polarity. These are usually related to in-filled cut features where the fill material is magnetically enhanced compared to the surrounding matrix. They can be caused by ditches of an archaeological origin, but also former field boundaries, ploughing activity and some may even have a natural origin.
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Geophysical Survey Report Project Name: Land at North West Malmesbury, Wiltshire Job ref: J7816 Client: Cotswold Archaeology Date: February 2015 ______
Positive linear anomaly with associated negative response
A positive linear anomaly which has a negative anomaly located adjacently. This will be caused by a single feature. In the example shown this is likely to be a single length of wire/cable probably relating to a modern service. Magnetically weaker responses may relate to earthwork style features and field boundaries.
Positive point/area
These are generally spatially small responses, perhaps covering just 3 or 4 reading nodes. They are entirely positive in polarity. Similar to positive linear anomalies they are generally caused by in-filled cut features. These include pits of an archaeological origin, possible tree bowls or other naturally occurring depressions in the ground.
Magnetic debris
Magnetic debris consists of numerous dipolar responses spread over an area. If the amplitude of response is low (+/-3nT) then the origin is likely to represent general ground disturbance with no clear cause, it may be related to something as simple as an area of dug or mixed earth. A stronger anomaly (+/-250nT) is more indicative of a spread of ferrous debris. Moderately strong anomalies may be the result of a spread of thermoremanent material such as bricks or ash.
Magnetic disturbance
Magnetic disturbance is high amplitude and can be composed of either a bipolar anomaly, or a single polarity response. It is essentially associated with magnetic interference from modern ferrous structures such as fencing, vehicles or buildings, and as a result is commonly found around the perimeter of a site near to boundary fences.
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Geophysical Survey Report Project Name: Land at North West Malmesbury, Wiltshire Job ref: J7816 Client: Cotswold Archaeology Date: February 2015 ______
Negative linear
A linear response which is entirely negative in polarity. These are generally caused by earthen banks where material with a lower magnetic magnitude relative to the background top soil is built up. See also ploughing activity.
Negative point/area
Opposite to positive point anomalies these responses may be caused by raised areas or earthen banks. These could be of an archaeological origin or may have a natural origin.
Ploughing activity
Ploughing activity can often be visualised by a series of parallel linear anomalies. These can be of either positive polarity or negative polarity depending on site specifics. It can be difficult to distinguish between ancient ploughing and more modern ploughing. Clues such as the separation of each linear, straightness, strength of response and cross cutting relationships can be used to aid this, although none of these can be guaranteed to differentiate between different phases of activity.
Polarity
Term used to describe the measurement of the magnetic response. An anomaly can have a positive polarity (values above 0nT) and/or a negative polarity (values below 0nT).
Strength of response
The amplitude of a magnetic response is an important factor in assigning an interpretation to a particular anomaly. For example a positive anomaly covering a 10m2 area may have values up to around 3000nT, in which case it is likely to be caused by modern magnetic interference. However, the same size and shaped anomaly but with values up to only 4nT may have a natural origin. Colour plots are used to show the amplitude of response.
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Geophysical Survey Report Project Name: Land at North West Malmesbury, Wiltshire Job ref: J7816 Client: Cotswold Archaeology Date: February 2015 ______
Thermoremanent response
A feature which has been subject to heat may result in it acquiring a magnetic field. This can be anything up to approximately +/-100 nT in value. These features include clay fired drains, brick, bonfires, kilns, hearths and even pottery. If the heat application has occurred in situ (e.g. a kiln) then the response is likely to be bipolar compared to if the heated objects have been disturbed and moved relative to each other, in which case they are more likely to take an irregular form and may display a debris style response (e.g. ash).
Weak background variations
Weakly magnetic wide scale variations within the data can sometimes be seen within sites. These usually have no specific structure but can often appear curvy and sinuous in form. They are likely to be the result of natural features, such as soil creep, dried up (or seasonal) streams. They can also be caused by changes in the underlying geology or soil type which may contain unpredictable distributions of magnetic minerals, and are usually apparent in several locations across a site.
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Amendments Issue No. Date Description ------ Stratascan Ltd - 2015
A
Survey area
Site centred on NGR ST 927 881
B
C
E D
G F OS REFERENCING INFORMATION
A 392483.21, 188389.21
B 392576.31, 188313.49
C 392599.58, 188294.56 I D 392692.68, 188218.84
E 392777.08, 188227.53
F 392800.36, 188208.60
H G 392650.47, 188214.50
H 392574.75, 188121.40
I 392762.50, 188162.05
J 392667.85, 188045.69
K 392841.01, 188020.86 J L 392746.36, 187904.49
Job No. Survey Date J7816 JAN-FEB 15 K Client
COTSWOLD ARCHAEOLOGY
Project Title LAND AT NORTH WEST MALMESBURY, WILTSHIRE
Subject
SITE LOCATION, SURVEY AREA & REFERENCING
STRATASCANTM GEOPHYSICS FOR ARCHAEOLOGY L AND ENGINEERING VINEYARD HOUSE T: 01684 592266 UPTON UPON SEVERN E: [email protected] WR8 0SA www.stratascan.co.uk
Survey area
SUMO GROUP Reproduced from Ordnance Survey's MEMBER 1:25 000 map of 1998 with the permission of the controller of Her Majesty's Stationary Office. Scale 0m 10 20 30 40 50 60 70 80m Crown Copyright reserved. Licence No: AL 50125A Licencee: 1:1250 Stratascan Ltd. Plot Checked by Issue No. Vineyard House Upper Hook Road A1 DGE 01 Upton Upon Severn WR8 0SA Date Drawn by Figure No. OS 100km square = ST FEB 15 TR 01 Amendments Issue No. Date Description ------ Stratascan Ltd - 2015
Plotting parameters +100nT
Maximum +100nT (red) +25nT Minimum -100nT (blue) +3nT
-3nT
-25nT
-100nT Job No. Survey Date J7816 JAN-FEB 15 Client
COTSWOLD ARCHAEOLOGY
Project Title LAND AT NORTH WEST MALMESBURY, WILTSHIRE
Subject COLOUR PLOT OF GRADIOMETER DATA SHOWING EXTREME VALUES
STRATASCANTM GEOPHYSICS FOR ARCHAEOLOGY AND ENGINEERING VINEYARD HOUSE T: 01684 592266 UPTON UPON SEVERN E: [email protected] WR8 0SA www.stratascan.co.uk
SUMO GROUP MEMBER
Scale 0m 10 20 30 40 50 60 70 80m 1:1250 Plot Checked by Issue No. A1 DGE 01 Date Drawn by Figure No. FEB 15 TR 02 Amendments Issue No. Date Description ------ Stratascan Ltd - 2015
Plotting parameters +2nT
Maximum +2nT (black) Minimum -2nT (white)
-2nT +2nT -2nT
Job No. Survey Date J7816 JAN-FEB 15 Client
COTSWOLD ARCHAEOLOGY
Project Title LAND AT NORTH WEST MALMESBURY, WILTSHIRE
Subject PLOT OF MINIMALLY PROCESSED GRADIOMETER DATA
STRATASCANTM GEOPHYSICS FOR ARCHAEOLOGY AND ENGINEERING VINEYARD HOUSE T: 01684 592266 UPTON UPON SEVERN E: [email protected] WR8 0SA www.stratascan.co.uk
SUMO GROUP MEMBER
Scale 0m 10 20 30 40 50 60 70 80m 1:1250 Plot Checked by Issue No. A1 DGE 01 Date Drawn by Figure No. FEB 15 TR 03 Amendments Issue No. Date Description ------ Stratascan Ltd - 2015
22 2
1 24 24 1 2 20 1 2 24 11 20 1 21 1 1 2 3 2 1 24 2 23 12 1 2 14 17 2 20 13 2 24 23 7 1 24 17 20 24 22 KEY 7 17 PROBABLE ARCHAEOLOGY 17 7 22 24 Positive anomaly / weak positive anomaly - probable 24 cut feature of archaeological origin Negative anomaly / weak negative anomaly - probable 17 24 bank or earthwork of archaeological origin 17 Linear anomaly related to a former field boundary present on available mapping pre-1900 17 23 Widely spaced curving parallel linear anomalies - probably related to ridge-and-furrow 23 POSSIBLE ARCHAEOLOGY 23 17 Positive anomaly / weak positive anomaly - possible cut 20 feature of archaeological origin 20 7 Negative anomaly / weak negative anomaly - possible 20 bank or earthwork of archaeological origin Linear anomaly - possible former field boundary not 17 17 present on available mapping 4 OTHER ANOMALIES 24 Closely spaced parallel linear anomalies - probably 24 17 related to agricultural activity such as ploughing Linear anomaly - probably related to pipe, cable or 17 other modern service 24 High amplitude linear anomaly related to a former field 17 23 boundary present on available mapping post-1900 24 High amplitude linear anomaly probably related to a 20 former footpath not present on available mapping 20 Magnetic disturbance associated with nearby metal 18 object such as service or field boundary 17 Strong magnetic debris - possible disturbed or made 24 ground 24 6 Scattered magnetic debris 7 Area of amorphous magnetic variation - probable 24 15 natural (e.g. geological or pedological) origin
17 24 Magnetic spike - probable ferrous object 5 20 Job No. Survey Date 7 7 23 J7816 JAN-FEB 15 Client 24 20 24 COTSWOLD ARCHAEOLOGY
24 Project Title 24 18 LAND AT NORTH WEST 19 MALMESBURY, WILTSHIRE 23 10 24 Subject 24 ABSTRACTION AND 8 23 INTERPRETATION OF 9 24 GRADIOMETER ANOMALIES 24 8 10 STRATASCANTM GEOPHYSICS FOR ARCHAEOLOGY 23 AND ENGINEERING 23 VINEYARD HOUSE T: 01684 592266 7 UPTON UPON SEVERN E: [email protected] WR8 0SA www.stratascan.co.uk 23 17 16 24
23 SUMO GROUP MEMBER
Scale 0m 10 20 30 40 50 60 70 80m 1:1250 Plot Checked by Issue No. A1 DGE 01 Date Drawn by Figure No. FEB 15 TR 04
STRATASCAN LTD Vineyard House Upper Hook Road Upton upon Severn Worcestershire WR8 0SA United Kingdom
T:0 1684 592266 F: 01684 594142 [email protected] www.stratascan.co.uk