About the Authors

João Zilhão

Joao.Zilhao@bristol.ac.uk

Affiliation Department of Archaeology and Anthropology, University of Bristol, Bristol, United Kingdom

Simon J. M. Davis

Affiliation Instituto de Gestão do Património Arquitectónico e Arqueológico, Lisbon, Portugal

Cidália Duarte

Affiliation Instituto de Gestão do Património Arquitectónico e Arqueológico, Lisbon, Portugal

António M. M. Soares

Affiliation Instituto Tecnológico e Nuclear, Lisbon, Portugal

Peter Steier

Affiliation VERA Laboratory, Faculty of Physics, University of Vienna, Vienna, Austria

Eva Wild

Affiliation VERA Laboratory, Faculty of Physics, University of Vienna, Vienna, Austria

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: JZ. Performed the experiments: AMMS PS EMW. Analyzed the data: JZ SD CD AMMS PS EMW. Wrote the paper: JZ SD CD AMMS PS EMW.