Vulsini, also known as Volsini

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

, Vulsini Volcanic District, Vulsini Volcanic Complex and the Vulsinian District, is a circular region of intrusive

igneous rock Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock ...

Lazio it, Laziale , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

, about to the north northwest of

Rome , established_title = Founded , established_date = 753 BC , founder = King Romulus (legendary) , image_map = Map of comune of Rome (metropolitan city of Capital Rome, region Lazio, Italy).svg , map_caption ...

, containing a cluster of

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

s known to have been active in recent geologic times. The Vulsinian region is one of dozens of intrusive circular regions, most smaller than the Vulsinian, arranged in a band from

Campania Campania (, also , , , ) is an administrative Regions of Italy, region of Italy; most of it is in the south-western portion of the Italian peninsula (with the Tyrrhenian Sea to its west), but it also includes the small Phlegraean Islands and the i ...

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, called the Roman Comagmatic Province. A comagmatic province is a geologic area of the same type and age

deriving from the same crustal magma. The Roman region is post-collisional; that is, the intrusions were not a result of the lateral stresses that created Italy and raised the

Apennines The Apennines or Apennine Mountains (; grc-gre, links=no, Ἀπέννινα ὄρη or Ἀπέννινον ὄρος; la, Appenninus or – a singular with plural meaning;''Apenninus'' (Greek or ) has the form of an adjective, which wou ...

, but were subsequent to Italy's creation. The Volsinian is the northernmost region. At relatively low altitude, the Vulsini calderas cover about and contain four

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

-age depressions known as Bolsena, Latera, Vepe and Montefascione calderas. An alleged eruption occurred in 104 BC, but it is currently considered a misinterpretation of the description of a fire, and the most recent confirmed activity occurred in Pleistocene. The largest, the Bolsena caldera, which is roughly across, is filled with the waters of

Lake Bolsena Lake Bolsena ( it, Lago di Bolsena) is a lake of volcanic origin in the northern part of the province of Viterbo called ''Alto Lazio'' ("Upper Latium") or ''Tuscia'' in central Italy. It is the largest volcanic lake in Europe. Roman historic ...

, which derive mainly from deep

aquifers An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...

. Immediately to the northwest are the combined Latera and Vepe calderas, about by . Vepe, to the north of Lake Mezzano (a very small crater lake west of Lake Bolsena) is what is known as a nested caldera; it arose in the previously existing Latera Caldera. Italian routes SS74 and SS312 follow the rim from

Valentano 250px, View of Valentano. Valentano is a town and ''comune'' of the province of Viterbo, in the Lazio region of central Italy. It is from the provincial capital, Viterbo. left, 220px, Rocca Farnese in Valentano. The placename is of uncertain ori ...

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Latera Latera is a small town and ''comune'' in the Province of Viterbo, Lazio, central Italy. Situated near Bolsena Lake and Mezzano Lake, is important for volcanic underground activity near the town centre. It has a small rock with a medieval palace ...

westward, turning off before Mezzano on the other side. In addition the small Montefiascone caldera, also nested, lies between

Montefiascone Montefiascone is a town and ''comune'' of the province of Viterbo, in Lazio, central Italy. It stands on a hill on the southeast side of Lake Bolsena, about north of Rome. History The name of the city derives from that of the Falisci (''Mons Fa ...

on its eastern rim and the lake. Two islands in the lake, Bisentina and Martana, were formed from airfall

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

s in Pompeii-like eruptions. Dozens of other tuff cones dot the region, mainly on the eastern side of the complex. The Italian Civil Protection Department considers Vulsini as extinct.

Subfeatures

The following tuff cones stand out in the region: * Monte Becco * Isola Bisentina * La Dogana * Monte Evangelista, * Isola Martana * Molino *

* Monte Montione *

* Monte Pilato * Monte Rosso * Santa Luce * Santa Maria di Sala * Selva del Lamone * Monte Semonte * Monte Spinaio * Monte Bandinio

References

External links

*
Calderas of Italy Potentially active volcanoes Pleistocene calderas Holocene calderas {{Lazio-geo-stub

Subfeatures

See also

References

External links