Mount Amiata (La Vetta) is a compound lava dome with a trachytic lava flow that extends to the east. It is part of the larger Amiata complex volcano. A massive viscous trachydacitic lava flow, 5 km long and 4 km wide, is part of the basal complex and extends from beneath the southern base of Corno de Bellaria dome. Radiometric dates indicate that the Amiata complex had a major eruptive episode about 300,000 years ago. No eruptive activity has occurred at Amiata during the Holocene, but thermal activity including cinnabar mineralization continues at a geothermal field near the town of Bagnore, at the SW end of the dome complex.