ABSTRACT

When the urban archaeologist phases his site he is in effect seriating his deposits by utilising stratigraphical relationships, similarities and dissimilarities in the nature of the deposits, his intuition and his experience. The errors which derive from the excavation process creep in at all levels. The back-fill in the pits may have been obtained by scraping soil from the surrounding area or less likely from the excavation of features elsewhere. The key factor is the disturbance of the ground; any layer which is the product even in part of the movement of soil is liable to contain residual pottery. At each site the excavation will reveal a series of local stratigraphies, but only occasionally will it be possible to relate these stratigraphies together. The generating algorithm could itself be unchanged and the known stratigraphy incorporated by adjusting the similarity values between nodes found in a known stratigraphy.