Archaeometallurgy in archaeological projects




Introduction

Many archaeologists lack experience of excavating and interpreting evidence for metalworking. The problems this causes can be overcome by consulting a metallurgical specialist. This leaflet outlines possible archaeometallurgical contributions at each phase of a project, and highlights the benefits of consulting relevant specialists and including them in the project team; names and addresses are provided. The comments below apply equally to other technologies such as glass working.

Some archaeometallurgical input can be beneficial to most archaeological projects, except those dealing with the earlier prehistoric periods. This is of two main types. The first is the identification of evidence for metalworking on site, which includes features like furnaces and hearths as well as finds such as slags, crucibles, moulds and scrap metal. The second is the structural or compositional analysis of metal finds which can add an extra dimension to conventional typological studies. Finds-based projects without a fieldwork component can also be enhanced by technical advice from an archaeometallurgist.

The procedures outlined below may appear a counsel of perfection that only applies in an ideal world. They do however define a standard to which we should aspire; without them important data will be destroyed or at best ignored. By working more closely together, archaeologists and archaeometallurgists can learn more about the metalworking processes carried out on individual sites, and hence improve not only the interpretation of those sites but global knowledge of past metalworking practices too.

Management of Archaeology Projects (MAP2, English Heritage 1991a) defines five phases through which large archaeological projects normally pass. These are:

Although this formal framework is only mandatory for projects funded by English Heritage, it can beneficially be applied to other archaeological projects. Any project will pass through equivalent phases even though they may not be identified in the same way.


Project planning and the formulation of research designs

Despite the frequency with which slags and other archaeometallurgical finds are discovered, it is not yet common for specialists to be approached at the project planning stage.

Where artefacts or deposits relating to mining or metalworking can be positively predicted, it is essential that an appropriate specialist is involved at this stage. With their help a research design can be developed that includes archaeometallurgical objectives, and an appropriate excavation and sampling strategy can be planned. This will benefit both the archaeological project and archaeometallurgical research. Geophysical prospecting can help locate and quantify metalworking deposits.

Even when the site is not thought to be primarily a metallurgical one, some contact with a specialist is desirable as small amounts of debris are not necessarily less important; most areas of archaeometallurgy would benefit from new evidence. Priorities on a national scale have been set out in Exploring our Past (English Heritage 1991b) and by the Historical Metallurgy Society (Cranstone 1991).

If consulted, specialists can make sure that the excavator is fully aware of the site's potential, and of what needs to be done if metallurgical debris is found so the maximum amount of information can be retrieved. Familiarisation with the range of finds and features that provide evidence of metalworking activities should be considered, even when no specific metallurgical input to the project design is thought appropriate. For EH funded projects, the archaeometallurgist should be included in the list of specialists in the original project design.


Fieldwork

When features that are thought to be `industrial' or large quantities of slag are discovered, advice should be sought from an archaeometallurgist on the interpretation of the features or on the strategy to be adopted for sample collection. For Roman or later ironworking a large quantity is c.100 kg or more but in the prehistoric period and for non-ferrous metalworking at all periods quantities are usually much smaller. If these finds turn up unexpectedly, early consultation will minimise the delays and extra costs that otherwise might arise. A site visit may be the best way to do this and can be combined with preliminary identification or confirmation of the range of metallurgical finds present. Advice to excavators and finds assistants on the collection and preliminary sorting of finds such as slag will reduce the resources necessary at later stages and simplifies future archaeo-metallurgical work, eg all slag needs to be washed but clay moulds may be damaged by enthusiastic cleaning. Site visits or other contacts during fieldwork are opportunities to maximise the archaeometallurgical potential of the site; consultation with a specialist after an excavation is over is not an adequate substitute. This is because some of the crucial materials and deposits, eg micro-residues, may not be recognised by the non-specialist and an adequate sampling strategy during excavation is often essential for a full interpretation. Quantification of sampling is vital, as is full recording of features. Finds in primary contexts rather than redeposited in pits etc are rare, so treat them as particularly important.

The product of this phase of the project is the site archive, which MAP2 defines as `the excavation records and any materials recovered. It should be quantified [and include] ... brief written observations on the artefactual ... data'. The interpretation of this statement, particularly in relation to finds, has varied widely. This led the Roman and Medieval Finds Groups to issue guidelines (Cool et al 1993) defining a standard for the basic record of all small finds and all groups of bulk finds. The presumption within English Heritage is that projects will normally proceed to assessment and usually to the analysis phase, so there is no need to produce detailed catalogues at this stage; a more restricted record will suffice.


Assessment of potential for analysis

This phase of a project is an opportunity to take stock of the data acquired in the course of the fieldwork, to update the research design in the light of the discoveries made, and to decide which parts of the data set warrant further investigation (analysis) - which may or may not include chemical analyses of finds.

The archaeometallurgical specialist can make a number of contributions at this stage. These are:

  1. assistance with assessing the potential of any industrial features,
  2. assessment of the potential of any metalworking finds,
  3. collaboration with other specialists in assessing the potential of metallurgical analyses to contribute to studies of the metal finds.
An experienced archaeometallurgist can reduce this work to a minimum. They will note any important or unique features of the assemblage but will not waste time on detailed examination of material of limited significance.

Assessment is defined by MAP2 as `a statement of the academic potential contained in the site archive'. Tasks for the archaeometallurgist include the basic identification of metalworking material (if the site archive does not contain adequate information) and its evaluation in the light of regional or national research priorities. Once an accurate record exists, assessment is primarily an intellectual exercise which examines these records in relation to the date, nature and relationships of the contexts in which the material was found. Ideally, assessment should not start until sufficient information about the contexts is available but in practice the two processes may have to proceed in parallel. Information on related finds (eg metal objects and fired clay/daub) assessed by other specialists should also be made available.

The assessment report must contain factual data, a statement of potential and recommendations (cf MAP2 Appendix 4). At the end of the assessment phase the project design must also be updated; it should incorporate the potential contribution of any unexpected discoveries. The opportunity this offers for incorporating archaeometallurgical objectives should not be used as an excuse for failing to consult a relevant specialist at the planning phase.


Analysis, report preparation, and dissemination

At this phase of the project the archaeometallurgist will be providing reports on features and/or groups of material that have been identified as having potential for analysis and that are linked to specific objectives in the updated project design. It is thus essential that all the planned work is covered by the documentation produced during the assessment phase.

The format and approximate length of reports should be agreed before work is started. Depending on circumstances, it may be appropriate to publish the archaeometallurgical data integrated into the main excavation report, or as a stand-alone paper in a national or local journal with a summary in the excavation report. Some projects may require both as the data will contribute to the interpretation of the site and also to thematic archaeometallurgical research. In some projects, dissemination may also be through temporary or permanent displays, eg in a museum. A full copy of all data produced at this phase will be supplied for inclusion in the site research archive.


References

Cool, H E M et al (1993) Guidelines for the preparation of site archives and assessments of all finds other than fired clay vessels. Roman Finds Group and Finds Research Group AD 700-1700.

Cranstone, D (1991) Metallurgical sites in Britain: priorities for research and preservation. Historical Metallurgy Society.

English Heritage (1991a) Management of archaeological projects, 2nd edition. English

English Heritage (1991b) Exploring our past: Strategies for the archaeology of England.

Copies of the English Heritage publications are available from Room 209, 23 Savile Row, London W1X 1AB; the Historical Metallurgy Society research priorities from the Hon Secretary, Peter Hutchison, 22 Easterfield Drive, Southgate, Swansea SA 2 2DB; and the Finds Groups guidelines from Jan Summerfield, c/o CAS, Fort Cumberland, Fort Cumberland Road, Portsmouth PO4 9LD.


Where to get help

The number of active archaeo-metallurgists is small, but most of them would rather be consulted than find out too late about missed opportunities. The specialist is the best judge of the significance of metallurgical finds so please accept their judgement as to what is an appropriate response.

The Ancient Monuments Laboratory and the Archaeology Committee of the Historical Metallurgy Society run occasional training days for archaeologists on how to recognise and deal with slags and other industrial debris. If you would like information on future Slag Days, please write to Dave Starley at the address below.

Some archaeologists and finds researchers have developed skills in the excavation of metalworking sites and in the identification and assessment of archaeometallurgical finds. They are often the best source of advice in the early stages of a project. However, they normally do not have access to the scientific facilities which can be used to check identifications and undertake detailed investigations.

The institutions listed below all have one or more scientists on their staff who are capable of providing metallurgical advice and services, including physico-chemical analyses of objects and samples. Some specialise in identifying metalworking debris while others focus on the application of a particular scientific technique. Where appropriate, they may refer you to another specialist. The individuals' special interests are listed but most are able to provide advice on a wider range of topics. Many different methods of artefact analysis are available; the choice depends on the question to be answered.

Please note that inclusion in this list is no commitment to provide help.


Ancient Monuments Laboratory
English Heritage,
23 Savile Row,
London W1X 1AB

Justine Bayley 0171 973 3320
Iron Age to medieval metal and
glassworking, artefact analysis
Dave Starley 0171 973 3306
Ironworking, especially medieval and
post-medieval, artefact analysis
Cath Mortimer 0171 973 3306
Non-ferrous metal and glass
working, artefact analysis

At present, advice is available to all, free of charge. If prior arrangements have been made, assessments and analysis of finds from EH funded projects will be undertaken free of charge. It is sometimes possible to provide a similar service for developer funded excavations, though a charge is normally made for this work. Material that contributes to current research projects is dealt with free of charge, even when not from EH funded projects.


Bradford University
Ancient Metallurgy Research Group,
Department of Archaeological Sciences,
Bradford BD7 1DP

Gerry McDonnell 01274 383 535
Ironworking, artefact analysis
Paul Budd
Bronze Age metallurgy

Joint research projects, small and large, are encouraged. Service work can also be undertaken at cost.


British Museum
Department of Scientific Research,
London WC1B 3DG

Paul Craddock

Several individuals work on archaeo-metallurgical projects but their activities are normally restricted to sites being excavated by the Museum or research on finds in the Museum's collections.


Durham University
Department of Archaeology,
46 Saddler Street,
Durham DH1 3NU

Chris Caple 0191 374 3622/3625
Phil Clogg
Artefact analysis

Joint research projects, small and large, are encouraged. Service work can also be undertaken at cost.


Institute of Archaeology
University College London,
31-4 Gordon Square,
London WC1H 0PY

John Merkel 0171 387 7050x4772

Offer MSc and PhD research in archaeometallurgy. Can provide advice but usually not any services.


National Museums of Scotland
Chambers Street,
Edinburgh EH1 1JF

Paul Wilthew 0131 225 7534
Artefact analysis

Deal mainly, but not exclusively, with Scottish material.


Oxford University
Department of Materials,
Parks Road,
Oxford OX1 3PH

Chris Salter 01865 273 728
Ironworking, artefact analysis
Peter Northover 01865 273 779
Non-ferrous metalworking,
artefact analysis

Joint research projects, small and large, are encouraged; advice and support given to student and society projects.


Royal Armouries
HM Tower of London,
London EC3N 4AB

Brian Gilmour 0171 480 6358
Artefact analysis


Scottish Analytical Services for Art and Archaeology
26 Kingsborough Gardens,
Hyndland,
Glasgow G12 9NJ

Effie Photos-Jones 0141 337 2623
Artefact analysis

Analytical services available at cost.


Sheffield University
Department of Archaeology,
Sheffield S10 2TN

Enquiries to 01142 826 075

Welcome discussion of dissertation projects for MSc students, involving analysis of materials from high temperature technologies.



Compiled by Justine Bayley (J.Bayley@eng-h.gov.uk), Ancient Monuments Laboratory, English Heritage in consultation with the Archaeology Committee of the Historical Metallurgy Society. February 1995
Copyright © 1995 Historic Buildings & Monuments Commission for England.



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