Iberian variscite: ICP-MS-LA and PIXE analysis of recent prehistory beads and pendants from Spain and Portugal

Abstract

At the European recent Prehistory variscite was a precious gemmological material that appears in scarce megalithic burials of the Atlantic facade, especially at the Iberian peninsula and West France. Here we describe the main results of the mineralogical and geochemical analysis of a great and diverse group of archaeological and geological variscite and turquoise samples from the Iberian peninsula, especially from the Atlantic facade and the SW of Spain. Samples were analysed last years by the use of different analytical techniques as XRD, WDXRF, ICP-MS-LA and PIXE and stereomicroscopy. The geochemical results, obtained especially by PIXE and ICP-MS-LA techniques, on these archaeological samples were discussed in relation to their possible provenance areas, related with the three main geological areas with variscite and turquoise outcrops in the Iberian peninsula: Palazuelo de las Cuevas-San Vicente area, that included other sites as El Bostal and Braganca district in Portugal; Pico Centeno mines, Encinasola area, in Huelva province, SW Spain; Gava mines in Catalonia, NE Spain, and other possible sources in Europe as Pannece, France. Geochemical data were subjected to statistical analysis selecting different chemical variables in variscites and turquoises. A relatively good discrimination has been obtained through an interactive geochemical model using specially the Fe-Cr-V relationship, represented by a triangular diagram and the elementary relationships between other chemical elements. These results show the existence, in Neolithic and Chalcolithic times, of great exchange networks of exotic or prestige lithic products that extended in Western Europe, hundreds and thousands of kilometres away from their source areas.