Vitrified material In: Kilpatrick, Maureen, Barbour, Jordan, Muir, Thomas and Hunter, Charlotte 'Guardbridge, Fife: A multi-period settlement with a multi-vallate fort'

A little over 36 kg of vitrified and other heat-affected material was retrieved during excavations at Guardbridge (Table 28). Vitrified material can be produced during a wide range of high temperature processes, from specialist metalworking to domestic hearths. This assemblage is dominated by a distinct but currently undiagnostic type of fuel ash slag and a small, but significant, number of fragments derived from non-ferrous metalworking and ironworking. The non-ferrous metalworking fragments comprise two late Bronze Age mould fragments and a possible crucible sherd (see Bronze Age Metalworking evidence). The few fragments of ironworking debris indicate both iron smelting and blacksmithing took place in the vicinity, probably in the Iron Age, though the dating for this activity remains uncertain. A large quantity of fuel ash slag was also recovered, possibly relating to the combustion of a wooden structure.