USING GEOCHEMISTRY TO INTERPRET PORCELLANITE STONE AXE PRODUCTION IN IRELAND

Stone axes are a major feature of the archaeological evidence for Irel and's prehistory, with over 20,000 examples recorded by the Irish Ston e Axe Project (ISAP). Porcellanite was the single most important raw m aterial used in the manufacture of stone axes in Ireland, accounting f or more than half of the total. Of the two known sources in Co. Antrim , north-east Ireland, the mainland site at Tievebulliagh has tradition ally been considered the more important, with the site at Brockley on the offshore Rathlin Island seen as a minor source. Trace element geoc hemical analysis of samples taken from the sources has resulted in the identification of a discriminant that can be used to separate the two sites. This has very significant implications as it is now also possi ble to distinguish their products, thus allowing the assessment of the relative importance of the sources. Initial results from the analysis of porcellanite axes, coupled with evidence from field work at the so urce sites, suggest that Brockley was as important a source as Tievebu lliagh. (C) 1997 Academic Press Limited.