Pre-Excavation Techniques
There are many techniques of archaeological investigation which do not involve actually digging, which can tell us a lot about certain types of evidence. When an excavation is planned, they can be used to help archaeologists decide where to target their resources.
Excavation is much more effective at answering questions about archaeology if the area under investigation has been studied and surveyed first. Occasionally, buried archaeological sites have left no trace at all either on the ground surface today or, in old maps, photographs or written records. In these cases, the discovery of archaeology is a complete surprise. This situation is quite rare, however. It is much more usual for the presence of an archaeological site to be detectable before any excavation. Earthworks, cropmarks, artefacts scattered in ploughsoil, previous finds, place-names, and descriptions or depictions in old documents and maps can all help to pin-point the existence of buried archaeological deposits.
Pre-excavation work involves using a ‘suite’ of techniques, all of which are applicable to some, but not all, archaeological situations. The greater the number of these techniques which can be used in combination, the higher is the likelihood of obtaining useful pre-excavation data. Studying published information, previous find-spots, existing aerial photographs, old maps and documents, and sites and monuments records is usually the most productive first step in locating the areas of archaeological interest. This is often known as a ‘desk-top’ survey. Following on from this, field techniques such as topographical survey, aerial reconnaissance, building survey and geophysical survey can be used to map the site and its structures in detail, allowing excavation areas to be carefully positioned over zones or points of interest.
Further Reading:
M. Bowden (ed.) Unravelling the Landscape, An Inquisitive Approach to Archaeology. (Tempus Books, Stroud, 1999).