How to Dig a Test Pit
Remember we don’t do the work unless you would rather we did: this is for you, your friends, neighbours and family. You will be guided through every stage so that the trench is dug to professional standards and you learn how excavation is carried out. Anyone can join in: children are welcome. Even if you don’t dig there are plenty of other essential roles that can be done sitting and/or in short bursts and without getting dirty!
The more we dig the better: all the information brought together will help recreate the landscapes of East Oxford from early prehistory to the modern day. And even if we don’t appear to find anything that is still an important result. For example it tells us that the area was probably not built over earlier; but some of the evidence is so small it takes a while to be extracted. The soil samples we take may provide information showing the area was cultivated or a meadow, or changed use over time.
Stages
1. Choose the location: not too near trees, bushes or walls and not over pipes or cables! Check we have gone over sensible precautions – see ‘Health and Safety’.
2. The trench is usually 1m (c. 3 feet) square or sometimes 1.5m by 1m. In very special circumstances you may consider something a bit bigger, but we will talk about that if the question comes up.
3. The pit is marked out (usually with string) – see ‘Laying out a Trench’. We need to do a map of where the pit is in your garden with measurements to surrounding objects/buildings that are not likely to move. We may also take a position reading with a special and more accurate Global Positioning System.
4. If the pit is in grass the turf is taken off in neat squares with a spade and stacked nearby on a ground-sheet, earth-side to earth-side and grass to grass – see ‘De-turfing’.
5. The soil is dug out, with trowels and shovels, in measured 20cm (0.2m) layers. Each layer – or ‘spit’ in archaeology-speak – is described on a special sheet, one for each layer. See ‘Describing the Soil’. If we find anything such as old building foundations or a noticeably different area of soil then those will be described on their own sheet.
5. All the soil is sieved either onto a ground sheet or straight into big bags standing on a ground sheet. This makes re-filling the pit easier and much less untidy. Anything we find in the sieve is kept and put into bags with the number of the layer from which the things came. We need to make a note of what comes out of each layer on the relevant sheet.
6. If the layer of soil being dug looks at all interesting we will take a soil sample in a special white bucket, which is labelled according to the name of the pit and the layer it came from. Later on this environmental sample will be put through a special series of sieves in water to collect old seeds and other tiny items which can tell us a great deal about the previous landscapes – see ‘Environmental Archaeology’. You are welcome to be involved in the processing and sorting and analysing of the material from your pit.
7. When we get down in the pit to geological layers (soil/sediment or rock) that have been undisturbed by human activity – called the natural in archaeology speak – we stop. Or when the pit is too deep! We can’t really guess beforehand how deep a pit will go as it depends on what happened on that little patch of land in the past.
8. Each of the four vertical sides of the finished pit is drawn to scale – see ‘Drawing the Trench’ and photographed.
9. The pit is filled in and turf returned.
10. Any finds are taken away for the moment – with your permission. They will be returned to you. They will then cleaned, identified, catalogued, photographed and some are drawn to scale – see ‘Dealing with Finds’. Again you are more than welcome to be involved in that process.
11. A short report will need be put together – again this is as much of a joint effort as you want it to be. With your permission – but without any details or photos which will reveal your exact address – this will be uploaded onto the website for registered users to consult. We will also – with your permission – display the rough location of the test-pit on an overall map of East Oxford on the website. The scale of the map and size of the symbol will be such that again your address cannot be identified.
12. We hope you will be interested enough to join us when the full-scale excavation goes ahead in East Oxford!
The Project Team www.archeox.net
