THE CARPENTER'S SHED
The chronology of Iona has gone through many phases since excavation began in 1956. When the first parts of this report were in a first draft a section on chronology was written which depended only on stratigraphy and subjective archaeological reasoning. Up to now it has been possible to avoid absolute dates by using general phrases such as early and middle monastic phases, Benedictine period, pre-or post-Viking, and post-Reformation periods. Black topsoil, flecks of mortar, unrusted iron and pottery from the seventeenth century on, serve to mark out all post-Reformation deposits quite clearly. Two main problems arise what weight ought to be given in an archaeological summary to dates which one know only from historical sources, and can these dates be fitted into an archaeological sequence. While the charcoal and wood dates from around the Abbey are by no means perfect they are far less problematic than the dates from Martyrs' Bay.