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Non-destructive characterization of archeological Cu-based artifacts from the early metallurgy of southern Portugal

  • Carlo Bottaini
  • Antonio Brunetti
  • Rui Bordalo
  • António Valera
  • Nick Schiavon
Original Paper

Abstract

In this study, Monte Carlo (MC) simulations combined with energy dispersive X-ray fluorescence (EDXRF) spectroscopy have been used to characterize non-destructively a collection of Cu-based artifacts recovered from two archeological sites in southern Portugal: (a) the Chalcolithic E.T.A.R. site of Vila Nova de Mil Fontes and (b) the Middle Bronze Age site of Quinta do Estácio 6. The metal artifacts show a multilayered structure made up of three distinct layers: (a) brownish carbonate soil-derived crust, (b) green oxidized corrosion patina, and (c) bulk metal. In order to assess the reliability of the EDXRF-based Monte Carlo simulations to reproduce the composition of the alloy substrate in archeological bronze artifacts without the need to previously remove the superficial corrosion and soil derived patinas, EDXRF analysis together with scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) was also performed on cleaned and patina-/crust-coated areas of the artifacts. Characterization of the mineralogical composition of the corrosion products in the surface patinas was further determined by means of X-ray diffraction (XRD). Results suggest that the adopted EDXRF/Monte Carlo protocol may represent a safe and fast analytical approach in the quantitative characterization of the bulk chemical composition of Cu-based metal artifacts even in the presence of fairly thick corrosion patinas and/or soil-derived encrustations at the surface of the archeological objects.

Keywords

Monte Carlo simulation EDXRF Early metallurgy Cu-based artifacts Southern Portugal 

Notes

Acknowledgements

This work has been financed by national funds by FCT–Foundation for Science and Technology under the UID project UID/HIS/00057/2013 (POCI-01-0145-FEDER-007702) and UID/Multi/04449/2013 (POCI-01-0145-FEDER-007649), COMPETE, FEDER, Portugal2020. The first author also thanks the FCT for the SFRH/BPD/111039/2015 grant and Robert Allen Zimmerman for support in writing the paper.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  1. 1.HERCULES Laboratory, Palácio do VimiosoUniversity of ÉvoraÉvoraPortugal
  2. 2.CIDEHUS, Palácio do VimiosoUniversity of ÉvoraÉvoraPortugal
  3. 3.Dipartimento di Scienze Politiche, Scienze della Comunicazione e Ingegneria dell’InformazioneUniversità di SassariSassariItaly
  4. 4.Era-Arqueologia SACruz QuebradaPortugal

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