87Sr/86Sr: a New Discriminant for Provenancing Neolithic Porcellanite Artifacts from Ireland

• Published in: Journal of archaeological science 2001-07, Vol.28 (7), p.713-720
• Main Authors: Curran, Joanne M., Meighan, Ian G., Simpson, Derek D.A., Rogers, Graeme, Fallick, Anthony E.
• Format: Article
• Language: English
• Subjects: Europe; Neolithic; Neolithic and chalcolithic; North West Europe; PORCELLANITE, IRELAND, AXES, ISOTOPIC ANALYSIS, TRADE; Prehistory and protohistory
• ISSN: 0305-4403; 1095-9238
• DOI: 10.1006/jasc.2000.0582

Antrim porcellanite (thermally metamorphosed Tertiary laterite) was the most common raw material used in the production of stone implements during the Neolithic in Ireland and was worked at two localities in North Antrim: Tievebulliagh, near Cushendall and Brockley on Rathlin Island. Attempts have been made to provenance material from these two known sources, the most successful to date being the use of geochemical data (Sr and Yppm). Here we present a new geochemical discriminant—Sr isotopic data—which reveal that Tievebulliagh and Brockley porcellanites are distinctive. Present-day87Sr/86Sr ratios form two discrete groupings ranging from 0·705894±25–0·706443±24 at Tievebulliagh and 0·704088±27–0·704587±25 at Brockley. A coherent relationship between87Sr/86Sr and Sr (ppm) reiterates the use of Sr content as a discriminant and illustrates the geochemical variability of Sr between these two sources. Although this is a destructive technique,87Sr/86Sr represents the best discriminant to date for Antrim porcellanites and will enable definitive provenancing of porcellanite artifacts from Ireland with important archaeological implications.