Excavations and Metal-working at Llwyn Bryn-dinas Hillfort, Llangedwyn, Clwyd

Abstract

Small-scale rescue excavations at Llwyn Bryn-dinas hillfort, on the Welsh Borderland, showed that the earliest fortification belonged to the late Bronze Age, with radiocarbon dates in the late 9th and 8th centuries be. A terrace, subsequently cut into the rear of the rampart to accommodate a metal-working floor, was associated with a radiocarbon date centred in the late yd century be. Detailed analysis of the metal-working debris suggests that copper-alloy casting, iron forging and possibly bronze production were carried out within a single workshop. The finds include a distinctive form of handled crucible. The industry appears to have been fairly small-scale, of short duration, and probably only designed to meet the internal needs of the hillfort population. The excavation adds significantly to the local evidence for metal-working during the later prehistoric period. A distinctive zinc-impurity pattern in the copper alloy and raw copper, previously identified in material from other sites nearby, confirms the suggestion of an Iron Age bronze-working industry based on a specific metal source in the north Powys area. In addition, analysis of the iron-working debris suggests the exploitation of a distinctive local ore body. The metal-working activity appears to have come to an abrupt end, possibly with the enlargement or local repair of the rampart. Later phases of activity include a final occupation deposit with an associated radiocarbon date centred in the mid 2nd century be.

Iron Age and Roman copper alloys from northern Britain

“…This may either result from the use of scrap containing small amounts of (imported ?) brass, or from the use of copper ores which contain zinc (this last possibility is discussed by Northover [in Musson, Northover & Salter 1992] in relation to lion Age copper alloys from the Welsh Borders).…”

“…Copper ores are usually smelted at c. 1200°C but zinc metal boils at 907°C and so simple co-smelting of zinc and copper ores will not produce brass. Northover (in Musson et al 1992) discusses the possibility that trace/minor levels of zinc might be introduced to smelted copper in this way. The loss of gaseous zinc during smelting can be avoided if the zinc ore is reduced in a sealed container.…”

The Production of Copper Alloys in Iron Age Britain

“…'imported) brass, or from the use of copper ores which contained zinc (this last possibility is discussed by Northover (in Musson et al 1992) in relation to Iron Age copper alloys from the Welsh Borders). These objects may also be intrusive to the Iron Age contexts within which they were found.…”

“…Alloys with minor levels of zinc (perhaps a few percent) could derive from the smelting of copper ores rich in zinc ores (Northover in Musson et al 1992). Alloys with minor levels of zinc (perhaps a few percent) could derive from the smelting of copper ores rich in zinc ores (Northover in Musson et al 1992).…”

Excavations at the Sarn-y-bryn-caled cursus complex, Welshpool, Powys, and the timber circles of Great Britain and Ireland

“…Nevertheless it is tempting to see domestic smithing taking place within the security of the defences of the enclosure as at Llanymynech, the Breiddin, and Llwyn Bryn-dinas (Musson et al 1992) while itinerant smiths, perhaps specializing within their craft, were relying on the sanctuary afforded by mystic or sacred locations. Nevertheless it is tempting to see domestic smithing taking place within the security of the defences of the enclosure as at Llanymynech, the Breiddin, and Llwyn Bryn-dinas (Musson et al 1992) while itinerant smiths, perhaps specializing within their craft, were relying on the sanctuary afforded by mystic or sacred locations.…”