Recording an archaeological site

As excavation destroys the physical evidence every site that an archaeologist excavates has to have detailed records. The records allow the archaeologist to write up the site and should be detailed enough to allow 3D reconstruction of the site.

Context sheets

A context is the result of one event or action in time. For instance, a pit that was dug and then allowed to silt halfway up before being backfilled with rubbish and soil has three contexts: firstly the digging of the pit; secondly the silting up and thirdly the deliberate backfilling. It is usually possible to see or feel the difference between these contexts in terms of the colour and compactness of the soil and any inclusions within it such as stones or artefacts.

It is important to keep a record of each context so that any artefacts that have been found within it can be linked back to their original context. Detailed records of the context can also help in the interpretation of its function and how it got there. The colour of the soil is recorded using a Munsell Soil Chart. This is a chart with standardised descriptions of colour. It is possible to smear some of the soil onto the laminated sheets to find the exact match in tone and hue. This can allow matching of contexts between trenches that may be separated. The context sheet will also record the excavator’s name so queries can be addressed to them. It is also recommended to record the weather conditions, which can be taken into account when looking at the information on the context sheet later. For example, colour differences in the soil may be clearer in brighter sunny conditions than in overcast conditions or poor visibility. A sample context sheet can be downloaded from this page.

Click here to see an example context sheet.

Going the extra mile

Bulk finds

Most artefacts will come under this category. Pottery, tile, brick, shell, flint flakes and animal bones are all classed as bulk finds on site. The finds from each context are bagged and labelled separately. The assemblage from each context will help to date it and provide evidence of how it got there and why.

Most artefacts can be washed (no detergent should be used) and cleaned with toothbrushes but there are some that should not be washed, like metal, charcoal and other carbonised artefacts. These can be lightly brushed with a soft brush when dry. Sometimes artefacts like pottery sherds, flints and teeth aren’t cleaned as they can be used for residue and use-wear analysis and brushing can destroy the evidence needed for these processes. Brushes can also damage finds such as friable prehistoric pottery or the slip on a pottery sherd, so sponges are often used instead.

Finds are then marked with the site and context or find number, if possible and appropriate. This ensures that their context is always known. Once the finds are marked they are sorted into artefact categories. Bones, pottery and flint all go to different specialists.

If you are in a position where you think you will be collecting artefacts, it is best to research which specialists are going to process your finds in advance so you know which groups to split them into. For instance, Roman Samian ware and amphorae often go to separate specialists. It will also give you an idea of how much to budget. The post-excavation analysis of the finds can take three to four times the length of the excavation.

The Institute of Field Archaeologists website has a list of Registered Archaeological Organisations. Many of them will have in-house specialists who can process your artefacts, for a fee. You may also be able to get your local museum to look at the artefacts for you, but this will probably be more cursory. Click here to find links to local museums.

Small finds register

Archaeologists also keep a register of small finds on site. Small finds, as they are often known, are special finds that are either rare or need conservation. These can include metal artefacts, flint arrowheads and so on. It is usual to record the 3D location (by reference to the site grid and Ordnance Datum or with a GPS device) of small finds and give them a unique number that is recorded in a small finds register. These will often need to be treated with care, not washed, and sent straight to the specialist for immediate attention. It is important to pack any fragile finds well so they do not become damaged in transit. They should not be packed with newspaper but with acid-free tissue paper or in purpose cut foam.

Samples

Soil samples are taken from sealed contexts. A sealed context could be the fill of a pit or ditch that has not been disturbed by ploughing or animal burrowing, for example, or an occupation layer that has been overlain by silt from a flooding river, for example. The soil is sieved or floated for environmental evidence such as mollusc shells, pollen grains and carbonised seeds. These are then sent to environmental specialists for identification and interpretation. This can help identify the environment around the site at the time the context was deposited; possibly give information about the economy and subsistence of a site; or can provide clues as to the date and function of the context and how material got there.

Levelling

The level of the site above the mean sea level (or OD – Ordnance Datum) is taken at regular intervals and with each context that is dug. This helps towards that 3D reconstruction of the site. Levels can be taken using a dumpy level, theodolite or an EDM. They are all compared to known landmarks or benchmarks in the vicinity, which can often be found on churches and other old stone buildings.

Photographs

Black-and-white photographs are usually taken of important features on an archaeological site, for instance a section through a feature such as a pit, ditch, hearth or post-hole. The contrast in black-and-white is better for showing the differences between contexts. Colour digital photographs are increasingly being taken, but mainly for publicity purposes and general recording.

Plans

Archaeologists plan features from a birds-eye view. Often features are planned individually and can be later incorporated onto a full site plan that will be tied into the national grid. All plans are tied into the site grid to allow each feature to be correctly located later. Large features are planned using tapes off-set from the site grid but smaller and more complex features require the use of a planning frame, a wooden frame with strings stretched across at regulat intervals, for more detailed work.

Example of a plan.

Sections

A section is a drawing of a vertical cut through a context or feature. It is drawn by setting up a horizontal string secured on long nails across or above the section using a line level. A tape is then stretched along the line and measurements taken with a hand tape above and below the string at intervals along the tape and marked onto the drawing.

Example of a section.

Recording an archaeological site

Going the extra mile

Further reading