Any remains encountered during the course of a survey are then analyzed in ASI's laboratories to determine their cultural and temporal affiliations and to assess their archaeological significance. For historic material, this analysis also involves comprehensive archival research.
Four archaeologists walk across a ploughed field conducting a survey.
Our survey strategies incorporate the current archaeological survey standards defined by the Ministry of Culture´s Archaeological Assessment Technical Guidelines. Lands which have recently been ploughed (within three to four weeks) are optimal for archaeological survey through systematic surface review, since potential visibility of cultural material on the surface is at its highest. Thus, all active or former arable lands that can be ploughed within a particular study area must be reploughed and allowed to weather prior to archaeological survey. Those lands that cannot be ploughed must be assessed by means of test pitting. Typical test pits are approximately 30-50 centimetres in width and are shovel excavated to subsoil, thereby allowing for an examination of stratigraphy and the detection of cultural soil horizons. Areas of high archaeological potential must be tested at five-metre intervals. The remainder may be tested at ten-metre intervals. Soil fills must be screened through a six-millimetre mesh. The pattern and intensity of testing may be adjusted in the course of fieldwork, due to environmental factors (eg. topography) and/or the on-going results of test pits.
Work in urban centres requires a different strategy, as many areas have long and complex development histories. In urban contexts, it must be recognized that some features associated with historic archaeological sites may survive, as deeply buried deposits, in areas that have been developed and even re-developed. Only where land has been completely altered (i.e., removed or regraded) to a depth of three metres or more should it be concluded that there is no potential for survival of archaeological remains. Our approach in urban areas is to develop a detailed land use history through review of historic maps, aerial photographs, assessment rolls, city directories, land registry documents and geotechnical studies. This research allows us to identify zones of remaining archaeological potential or sensitivity, which are then examined through fieldwork involving borehole or test trench excavation.
The early detection of a significant archaeological site through a detailed assessment allows for the modification of a project's plans with a minimum of delay and expense. At this stage, various strategies, encompassing both the client's needs and the heritage value of the site, are considered.
