The earliest eruptions of the volcano occurred around one million years ago, explosive activity producing
ignimbrite. The explosive eruption phase finished around 830,000 years before present, when the nature of the activity changed to a mix of pyroclastic and effusive,
lava eruptions which built up the mountain and which have been dated to around 500,000 years ago. One of the explanations advanced for the Valle dei Grigi is that it is the result of the collapse of a sector of the mountain, as occurred during the
1980 eruption of Mount St. Helens and the
1792 eruption of Mount Unzen. The most recent phase involved further lava flows and the growth of
lava domes in the Valle dei Grigi, including the formation of two calderas. The most recent activity is thought to have been
phreatomagmatic explosions around 40 ka ago which produced
maars and small
cold surges (pyroclastic surges cooler than 100 °C). Active outgassing of carbon dioxide and other mantle-derived volatiles occur from Monte Vulture and the surrounding region. ==See also==