J. Phys. IV France
Volume 104, March 2003
Page(s) 523 - 526

J. Phys. IV France
104 (2003) 523
DOI: 10.1051/jp4:20030137

Analysis of a Roman Centaurus from Canas de Senhorim (Portugal)-Comparative study using EDXRF and SXRF

M.F. Araujo1, T. Pinheiro1, P. Valério1, A. Barreiros2, A. Simionovici3, S. Bohic3 and A. Melo4

1  Instituto Tecnologico e Nuclear, Estrada Nacional 10, 2686-953 Sacavém, Portugal
2  Instituto Nacional de Engenharia e Tecnologia Industrial, Azinhaga dos Lameiros, 1649-038 Lisboa, Portugal
3  European Synchrotron Radiation Facility, BP. 220, 38043 Grenoble cedex, France
4  Museum Nacional de Arqueologia, Mosteiro dos Jeronimos, Praça do Império, 1400-206 Lisboa, Portugal

A decoration figure of a ritual bronze vase from Canas de Senhorim (Portugal) was analysed by Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometry and Synchrotron Induced X-Ray Fluorescence (SXRF) microprobe spectrometry. This artefact, a Centaurus constitutes the first evidence for a possible Roman occupation of this region of Central Portugal and it is also one of the very few artefacts of this type ever found. The determination of the Centaurus alloy composition will be important in me further comprehension of the metallurgical technologies used by the Romans in this region. EDXRF analysis of the corroded surface were made using the monochromatic radiation emitted by Ag and Gd secondary targets excited by a Rh X-ray tube at 35kV and 57 kV, respectively. SXRF experiments were carried out both on the corroded surface and on a small clean area of the artefact, using both monochromatic and polychromatic excitations with 32 keV and 12 keV radiations. EDXRF results allowed the determination of the alloy bulk composition. The SXRF comparative analysis between the clean and corroded areas evidences the surface enrichment in Sn and establishes the composition of the original alloy. The Centaurus alloy is a bronze with rather high Pb content, which is characteristic of the Roman decorative artefacts.

© EDP Sciences 2003