As a general rule, archaeologists try to avoid excavation on the principle that preservation without disturbance is the best option for an archaeological site. Whether responding to a threat (e.g. from coastal erosion) or pursuing a research theme, the principle of minimum intervention should govern how the site is treated. The process of excavation has four stages: excavation, post-excavation, reporting, disposal. Where the site is not fully excavated, then a phase of site re-instatement and consolidation follows excavation.
After survey and other research have identified the key objectives of excavation a process of careful, monitored and recorded destruction takes place. The techniques of using a mechanical excavator, a pick-axe or a trowel are simple and, under supervision by an experienced archaeologist, are quickly learnt. The aim of excavation is to enhance our understanding of the site, the process is to acquire evidence to allow archaeologists to reconstruct how and when the site accumulated. The usual outcome of excavation is a large volume of partial, sometimes connected strands of evidence.
Post excavation studies
The investigation of a site is never completed at the end of fieldwork: interpretations in the field need to be challenged, tested and enhanced by analysis of the observations made in the field and of materials excavated from the site. A typical suite of analyses will include:
- Analysis of the artefacts (tools, pots etc) to inform us about the people who once occupied the site lived their lives;
- Analysis of the ecofacts (e.g. the plant and animal fragments recovered through excavation or sampling) to inform us how the occupants ate, how they exploited and affected their contemporary landscape. Ecofact studies also offer materials for radiocarbon dating (see below).
- Analysis of the records from excavation to allow us to challenge or confirm the field interpretation of when and how the site was built and modified, and how surviving deposits accumulated. This may also include a re-assessment of the evidence from survey and other background research to give fresh insights into the field evidence.
All archaeologists adhere to the general principle that of letting colleagues and the general public know what knowledge has been gained from excavation. The aim is therefore to publish a report on the work in a journal or a book. You can find examples of such reports in the Proceedings of the Society of Antiquaries of Scotland which are available in most libraries and on the web. You should also look at Scottish Archaeological Internet Reports
. Excavation without reporting is simply the destruction of a site for no benefit.
The published report will not cover every strand of evidence. Sometimes this is because not all strands are relevant to the main thrust of the investigation. At other times the archaeologist may fail to understand the value of the evidence. It is therefore important to preserve the evidence that supports the published interpretation. To this end the paper or digital records of the excavation should be deposited with a recognised archive institution: in Scotland this is the Royal Commission for Ancient and Historical Monuments of Scotland
, while artefacts and ecofacts are packaged up safely and disposed of via the Treasure Trove Unit
to the appropriate museum for display or storage.