Excavation is probably the form of archaeological work that the public are most familiar with and may also be known as a dig. As excavation is a destructive process and the archaeological resource is limited it is the stated policy of the National Monuments Service to preserve archaeological sites in situ whenever possible. In the commercial sphere excavation is only undertaken when it is not possible for a development to proceed without negatively impacting on archaeological features or deposits which may have been uncovered on a site. This is known as rescue excavation. The excavation process includes both on site works and office based post-excavation analysis and report compilation.
Archaeological excavations require a licence from the National Monuments Service and the National Museum of Ireland. In order for a licence to be issued a method statement explaining how the excavation will be undertaken must be submitted and approved. It is a condition of the licence that a full report on the excavations findings be submitted within a year of completion of on site works.
Put simply, excavation is the systematic dismantling of an archaeological site in order to obtain as much information as possible from that site. Excavation is used as a last resort and is only undertaken when it is not possible to preserve the site while allowing development to proceed. The term excavation does not just refer to digging a site, it includes the subsequent analysis of material uncovered and the writing of a report. The process of archaeological excavation is strictly regulated by the relevant statutory authorities.
When archaeological features or deposits are uncovered on a development site and it would not be possible for the development to proceed without impacting upon these deposits then an archaeological excavation is required. This is also known as preservation by record or rescue excavation.
Excavation is a labour intensive process which involves the systematic demolition of a site in order to determine its date and function. Archaeologists excavate a site using hand tools and make a complete record of the work using photographic and survey equipment and by making detailed maps and illustrations and compiling written records. Samples of soil and ecological material may also be recovered in order to assist interpretation.
An essential part of the excavation process is the subsequent analysis of the records and material uncovered in order to compile a report on the excavation findings.