Non Destructive Sourcing of Obsidians by Two Different Home Made pXRF Devices: Analytical Capabilities for Provenance Studies
Galv√£o, T. D.; Appoloni, C. R.;Poupeau, G.; Lopes, F. and Scorzelli, R. B.

Introduction
The main objective of this work was to characterize and test provenance discrimination of twenty two obsidian samples: twenty samples from Ecuador (Cotopaxi, Quiscatola, Mullumica, Rio Guambi e Oyacachi) and two from Italy. Two portable Home-MadeX-ray fluorescence spectroscopy (pXRF) devices were used, both with a SiPIN detector, one employing an Ag X-ray tube and another with a W X-ray tube. Elements K, Ca, Ti, Mn, Fe, Rb, Sr, Y, Zr and Nb were detected in all samples. The two-dimensional graphs of ratios Rb/Fe vs. Rb/Sr, Mn/Ca vs. Rb/Sr,Zr/Fe vs. Rb/Sr, Ti/Mn vs. Rb/Sr showed that four samples of obsidian from Cotopaxi are grouped to form a distinct group as well as two samples of obsidian from Quiscatola, while samples Mullumica, Rio Guambi and Oyacachi form a large group. Results were compared with those obtained by more robust techniques, for instance, INAA, ICP and PIXE. A good relative analytical capability was observed for the two systems used for elemental characterization and provenance studies.

Full Text: PDF     DOI: 10.15640/jaa.v8n1a1