1. Department of Analytical Chemistry; University of the Basque Country (EHU/UPV); P.O. Box 644 E-48080 Bilbao Spain
2. Arkeologi Museoa/Archaeological Museum of Bizkaia; Calzadas de Mallona 2 48006 Bilbao Spain
3. Department of Geography, Prehistory and Archaeology; University of the Basque Country (EHU/UPV); P.O. Box 644 E-48080 Bilbao Spain
4. Unesco Chair of Cultural Landscapes and Heritage; University of the Basque Country (UPV/EHU); P.O. Box 450 01080 Vitoria-Gasteiz Spain