Provenance and trade of volcanic rock millstones from Etruscan-Celtic and Roman archaeological sites in central Italy

Rectangular hopper-type (Olynthian style) and rotary (Pompeian style) millstones were found in archaeological sites at Mte Bibele (4th-3rd century BC, Etruscan-Celtic Age) and Fossombrone (2nd century BC-6th century AD, Roman Period), respectively. All the hopper-type millstones from Bibele and three rotary millstones from Fossombrone were made from leucite phonolite lavas from the same quarries near Orvieto, Vulsini volcanic district. As these leucite phonolites were also used in the Iron Age (pre-6th century BC) to produce small oval and saddle querns, a long continuous period of quarrying and production of millstones is established for the Orvieto centre. Euganean Hills (Na-trachyte), Etna (hawaiite) and Iblean Mts (tholeiitic basalts) were also identified as additional sources of material at Fossombrone. Major- and trace-element analyses are reported.