PIXE analysis and fission track dating of obsidian from South American prehispanic cultures (Colombia, Ecuador)

In the present work we have coupled PINE with fission track dating to chara cterise obsidian artefacts from about 40 archaeological sites of Colombia a nd Ecuador. PIXE analysis, carried out with the external beam line of the A GLAE tandem accelerator, yields the content in about 15 elements with Z > 8 , whereas fission track dating is applied to ages in excess of about 10 000 years. About 120 artefacts were investigated by PIXE, of which 50 were dat ed by fission tracks. Ages and compositions were compared to those of obsid ians from all known geological sources of the region. We show that this dou ble characterisation allows us to determine the number of obsidian sources exploited in an ancient past and to give some insight into obsidian circula tion. (C) 1999 Elsevier Science B.V. All rights reserved.