St Leonard's Excavation — the second season

November 2002 Update

Welcome to the first update following the 2002 training excavation! Back-filling of the site took place in September, and post-excavation work is now underway. Plans are already being laid for a further training excavation at St Leonard's next year- watch out for the next update in December, when details and a booking form should be available.

Following an excavation several tasks have to be undertaken in the immediate aftermath. This is generally known as 'post-excavation' work. One exercise, undertaken by staff at the YAT Conservation department, is the care of delicate finds (such as glass) and organic finds (such as leather) which otherwise would deteriorate rapidly; this task will be the subject of a future web update this winter.

Another post-excavation duty is to ensure that the site records accurately reflect the site as it was excavated. The written and drawn records for each separate deposit, cut and feature should reflect their character and function. This information also shows how the individual contexts relate to one another - for example, whether a timber post is isolated or part of a wall. The relationship of the contexts to each other is known as stratigraphy.

Toby Kendall digitising records from St Leonard's

Participants in the St Leonard's Hospital excavation will know only too well that urban excavations are normally so rich in data (such as the complex stratigraphy and the large number of finds) that they take a long time to dig. Such excavations take even longer to interpret at the post-excavation stage. However, the reward for this work is to be able to explain in great detail what happened on the site in the past, and how this changed over time. It is for this reason that YAT has been helping to devise a system of storing all of the data from an excavation electronically; Mike Rains, the Head of Computing at YAT, has been developing this system for several years. This electronic system is known as the Integrated Archaeological Data Base (IADB) because it combines information about contexts, finds and stratigraphic relationships.

The advantages are that the whole range of information from the site can be retrieved quickly, and that this data can be manipulated easily - for example, to check whether that timber post is part of a wall. The context drawings are digitised so that they too can be reviewed and manipulated.

IADB digitised plan from St Leonard's

In the past, it was normal for the stratigraphic interpretation to commence after the excavation had finished, but IADB provides an opportunity to study the excavation data as it is being produced, provided the data can be inputted immediately. This task will therefore be undertaken by some of the placements at St Leonard's Hospital in 2003. The results should be an eye-opener for everyone who takes part!