#1 - Find your feature.
Once the area to be investigated has been stripped of topsoil and subsoil by the nice man in the digging machine any ditches, pits etc. should show up against the background of the natural geology, like so.....
Here we have a small hearth. A fire has been lit, the heat from which has baked the clay surrounding it and turned it orangey/pink. This can be seen as a halo around the outside of the feature. The small depression left in the ground, full of ash and charcoal, has then either been deliberately covered with soil or it has become covered by natural processes over time. We first need to remove this soil layer, keeping the charcoal and heat affected clay intact so it can be recorded in situ and a sample taken. In order to show the different layers of deposits in a feature we do not take out the whole of the fill but just half so that a profile of the feature can be recorded (yes folks, it IS possible to dig half a hole!). Each layer is given its own number, called a context number, and will be recorded on a context sheet later.
#2 - Half section your feature.
Set up a couple of nails and string across the centre of the feature, this will act as a guide while you take out the upper fill.
As you are removing the fill you must keep the side of the other half as straight and vertical as possible to show the stratigraphy (layers) of the feature and keep it looking neat and tidy. Any stones or artifacts etc. that lie between the two halves should be worked around and left sticking out of the section, they should never be pulled or dug out of the section as this would leave an unsightly hole and not be a true representation of the interior of the feature. Any artifacts found should be placed in a finds bag labelled with the site code and context number of the layer it was found in.
After removing the upper soil fill but leaving the hearth contents and the heat affected surrounding clay in situ you should then photograph the feature using an appropriately sized scale and a story board stating the site code, area and the feature's number. This should also indicate the direction the photograph is taken from.
#3 - Take a sample.
After removing and photographing the upper fill you are now ready to remove the lower fill and take a sample of it for carbon dating, environmental analysis etc.
After placing the sample in a sample bag or tub you should write out two labels with the sample number, the context number of the layer sampled and the site code, one label goes into the bag and the other is attached to the bag using the string, zip tie or whatever else you are using to tie the bag shut. A sample sheet should then be filled out describing the properties of the context, what percentage of the context the sample represents, what information is required of the sample etc.
#4 - Take a photo.
Once the feature is completely excavated a photograph should be taken as before with a scale and story board. Here is a close up showing the two distinct layers within the feature, note the charcoal in the lower layer and the orangey/pink colour in the base showing how the heat has baked the surrounding clay.
#5 - Draw the section.
After photographing the section a scale drawing should be made at a scale of 1:10. To do this you should set up your string again a few cm above the feature and make sure that it is perfectly level using a string level.A height will be taken on the string later in order to ascertain the height above sea level of the feature.
After the drawing is completed it should look something like this.
A context sheet is then filled in for each layer within the feature. This describes the compaction, colour and composition of the layer, what inclusions it contained (stones, charcoal etc.) and in what quantity, and the measurements of the layer (extent, thickness etc). There is also a space for a sketch of the feature, in plan and profile. We will go into the context sheet in more detail in a later post.
And there you have it! You now have the ability to go on site and dig a simple feature such as this. Keep an eye out for future articles in this series and we will soon have you digging like a pro! (a professional that is, not a prostitute).
Happy digging!
Cheezey D x
