ASK THE ARCHAEOLOGIST:

The answers to the most frequently asked questions about archaeology

Dave Weldrake
Education ad Outreach Coordinator

Question 2: How deep do you have to dig?

It depends. Sometimes when you're digging in the open countryside, the archaeology may only be a few centimetres below the surface of the ground. In the older cities such as York or London there may be several metres of archaeology. Some of your pupils might know about the Jorvik Viking Centre in York. This is based on the results of an excavation at Coppergate which was so deep that the excavators had to use a ladder to climb out of the site.

It's all due to how many different buildings have been built on a site. If a rich Roman built a villa in the county (a villa is a sort of high status farm), the land on which it stood might go back to agriculture when the buildings were demolished. Plants and falling leaves would soon cover the site and all this vegetable matter would be turned into soil by the action of beetles and earthworms.

If the rich Roman built himself a town house, its foundations might have been covered and built on many times: by the Anglo-Saxons, the Vikings, the Normans, the Tudors and Stuarts, the Georgians, the Victorians and by modern people. Every time a structure is knocked down it leaves a demolition layer behind it. Over the years these build up and the current street level may be several metres above the original ground level.

Archaeologists call the study of these different layers in the soil stratigraphy. There's more about stratigraphy in FAQ 3: How do you know how old an object is? There are also suggestions for activities for you to try out in class and more websites to look at.