|
Four members of UWHG attended this seminar in York and enjoyed a thoroughly interesting day, which gave us plenty to think about with regard to our own methods and approaches.
Our host, John Kenny, introduced us to the two speakers, Nicky Rogers, Finds Researcher, and Ian Panter, Principal Conservator.
Nicky Rogers gave us an overview of the different types of finds one can expect on the typical archaeological site (if there is such a thing), which she discussed first according to the materials.
Iron
75% of metalwork assemblages are of iron. The YAT always x-rays such finds. Usually found as tools, nails, slag – but often brought to a site as infill
Bronze and other copper alloys
Usually identified initially by the green colour. Often cast or made from sheet metal. Most commonly found in dress accessories or other forms of ornamentation.
Lead alloys
Soft metal alloys such as pewter are most often found in brooches, badges and tokens, or as a building material used in roofing and stained glass windows.
Gold and silver
Naturally the most precious metal objects are coins and jewellery.
Stone
Often difficult to use as dating evidence due to their durability and frequent re-use (often as a building material), but the geological evidence can be a useful indicator of trade connections. Common stone objects include quern stones, hones and whetstones, mortars and pestles, and moulds
And also objects made of:
Glass, Clay, Amber, Jet, Antler, Bone, Horn, Ivory, Leather, Wood, Textiles
Nicky followed with an overview of the range of functions which can be attributed to archaeological artefacts:
Industrial & craft activity; Building materials; Domestic utensils and vessels; Structural iron work; Security items (eg. Keys, door locks); Personal items (eg. dress accessories, jewellery, toilet equipment); Reading and writing (eg. Seals, pens, book clasps, wax tablets); Religious artefacts (eg. Rosary beads, pilgrim badges); Recreation (eg. Gaming pieces, dice, musical instruments); Trade and exchange (eg. Scales and balances, coins, weights); Horse equipment (harnesses, horseshoes); Weaponry and military.
Questions can be asked of all these artefacts, such as – what are the origins of the materials (indicating trade routes or localization of the economy); what were the choices being made by the owners of these artefacts (social status, utilitarian, cultural); why and how were these items deposited and/or later disturbed or moved?
Through such questions the research process for an artefact is intended to identify material, function, origin, date, typology, and context. However, potential complications in this research can include individuality (the object is not a typical example of its kind); residuality (the object was found in a context dating much later than the object itself, due to re-use - such as heirlooms - or re-location – such as in building material); or intrusion (the object is found in a context dating to an earlier period – such as objects moved by animal disturbance into earlier layers).
Nicky then moved onto to the important questions of what the implications of these different types of artefacts pose for excavation planning. For instance, what kind of artefacts are expected from a site will impact upon funding for specialist and laboratory analysis, storage and preservation procedures and facilities, research into previous excavations and reports, and procedures for finds recording – i.e. what constitutes a “Small find” as opposed to a “Bulk find”.
Quantity is not necessarily the defining factor here, since York archaeologists treat all leather finds as “Small finds” – in such cases, it is the bag containing a few fragments of leather off cuts that is regarded as the “small find” rather than each and every individual piece of leather.
The standard definition of “Bulk finds” (e.g., non-worked animal bones, building materials) and “Small finds” caused UWHG delegates a little confusion – since pottery fragments, Nicky informed us, are usually recorded as “Bulk finds” – we’re lucky if we can find one or two pieces on our excavations in the Chapel House Wood area – in which case, Nicky conceded, we can treat them as “Small finds” after all. There followed some discussion of the definition of “Bulk” and “Small” finds, an important distinction because the audit trail for a small find should be much tighter than for a bulk find. The alternative method of assigning the label “Recorded find” was offered as an interim measure for on-site processing.
Another interesting outcome of the discussion after Nicky’s talk was that some groups include a code of Material type, as well as Site and Context codes for each Finds Number.
The second talk in the morning session was given by Ian Panter, Principal Conservator at YAT.
He discussed the main agents of decay – water, oxygen, living organisms, light, temperature, humidity, and of course, people – which may come into effect before, during, or post-excavation. The decay timeline normally begins with initial deterioration immediately at deposition, which eventually reaches an equilibrium within the buried environment – only to resume rapidly again on excavation.
For this reason, every care needs to be taken to keep decay and destruction to a minimum, through a range of means depending upon the object – the wearing of cotton or latex gloves, appropriate packaging and storage, careful handling, preventing direct contact with human skins and sweat.
Ian provided very helpful and practical advice on handling artefacts on-site and in the post-excavation stages – for example, fragile items can be lifted from an excavation by first being wrapped in cling film and then a layer of plaster of paris bandages to hold it securely as it is lifted. Other practical hints included - never store items in cotton wool, metal tins, or pvc envelopes, but preferably in sealable bags. Metal items, he advised, should always be allowed to dry out completely (for between 24 to 48 hours) before bagging. Finds bags should be stored together inside plastic boxes with a few small silica sachets (about 6 for a 13 litre box) to absorb any condensation. Humidity strips are useful to keep a check on moisture levels (which should not fall below 15-35%, depending upon the type of material). He also advised using inert jiffy foam to provide support for fragile items within finds bags, and plastazote foam inside storage boxes, and advised against wrapping items with paper, as this necessitates disturbing the find in order to look at it. Instead, crumpled acid free tissue can be used to cover an object without harming it (the exception being lead objects, which should be kept away from all paper and wood based storage containers). Ian’s useful and practical advice continued with the suggestion that black bin liners be used to line boxes containing soil blocks or other organic finds, as this inhibits light, and thus prevents the growth of algae blooms. Bone, conserved wood and stonework should be stored in acid free card boxes or boxes of inert plastic sheeting, and supported by black plastazote foam, “like a well organized sock draw”.
In the afternoon, we were given the opportunity to handle a selection of artefacts found in York, and visited the conservation laboratory where we were able to see a very well-organised operation where everything from a Bronze Age wooden “platter” shaped object to a medieval leather shoe and a Victorian marble bust were undergoing treatment.
For further information:
York Archaeological Trust - http://www.iadb.co.uk/
The Conservation Register - http://www.conservationregister.com/
The Portable Antiquities Scheme - http://www.finds.org.uk/
Conservation Advice Notes - http://www.finds.org.uk/conservation/
Watkinson, D. and Neal, V. – “First aid for finds” (Rescue, and UK Institute for Conservation Archaeology, 3rd ed., 1997)
The handouts from the workshop are available for loan to UWHG members from the Group’s Library collection
Jane Lunnon
Back to top
|
