GIS based interpolation applied to distinguishing occupation phases of early prehistoric sites

Traditionally sites occupied by mobile groups, without clearly identifiable contexts or phases, have been excavated according to arbitrarily defined vertical spits. The disadvantages of this approach are obvious—where occupation occurred on an undulating or sloped surface, stratigraphic levels or activity horizons, if they existed, are often unlikely to be identified and it becomes almost impossible to differentiate different phases of occupation within any period. Recently, three-dimensional recording of artefact locations with survey equipment with a memory store, such as total stations, has become more common on these types of sites. However, the excavation methods and means of interpretation needed to link this type of three-dimensional resolution with stratigraphic levels has been lacking, particularly as “true” 3 programs are not widely available to deal with this type of information. In this paper, a possible method for recording and modelling stratigraphic relationships using typical “almost 3 ” GIS programs is described.