Mysterious Eruption Came from Campi Flegrei Caldera

Boulder, Colo., USA: The caldera-forming eruption of Campi Flegrei (Italy) 40,000 years ago is the largest known eruption in Europe during the last 200,000 years, but little is known about other large eruptions at the volcano prior to a more recent caldera-forming event 15,000 years ago.