Aurunci Mountains

Aurunci Mountains
Monti Aurunci
Location of the range in Italy Location of the range in Italy
Highest point
Peak	Monte Petrella
Elevation
Coordinates
Naming
Etymology	Ancient tribal name
Geography
Country	Italy
State/Province	Lazio
District	Latina, Frosinone
Range coordinates
Parent range	Apennine Mountains, Volsci Chain
Borders on	Monti Ausoni, Liri River, Garigliano river; Tyrrhenian Sea
Geology
Orogeny	Southern Apenninic Orogeny
Age of rock	Messinian of Miocene, Pliocene-Pleistocene
Type of rock	limestone karst

The Monti Aurunci or Aurunci Mountains is a mountain range of southern Lazio, in central Italy. It is part of the Antiappennini, a group running from the Apennines chain to the Tyrrhenian Sea, where it forms the promontory of Gaeta. It is bounded to the north-west by the Ausoni Mountains, to the north by the Liri river, to the east by the Ausente, to the south-east by the Garigliano and to the south by the Tyrrhenian sea. The line between the Aurunci and the Ausoni has not been clearly established but the Aurunci are considered by convention to be east of a line through Fondi, Lenola, Pico, S.Giovanni and Incarico. Altitudes vary from hills to the 1,533 m of Monte Petrella. Main peaks include the Redentore (1,252 m) and Monte Sant'Angelo (1,402 m). They include a Regional Park, the Parco Naturale dei Monti Aurunci, created in 1997.

The mountains take the name from the ancient tribe of the Aurunci, an offshoot of the Ausoni. Both tribes were derived from the Italic people who were called by the Romans the Volsci; hence, the Monti Lepini, the Monti Ausoni and the Monti Aurunci are also called the Volsci or Volscian Chain. Coincidentally they are all of the same karst topography and have the same orogeny, which is not quite the same as the Apennines proper.

Geology

The Monti Aurunci mainly consist of friable limestone, which becomes harder toward Gaeta. The degree of faulting and cracking is so high that the mountains retain no rainfall; it sinks in to emerge as springs (and in human times wells) on the lower flanks. The stream beds are dry except for vernal pools.

Most generally, the western central coastal region of Italy is the front of a subduction zone where the African plate moving locally from southwest to northeast is carried under the European plate. There is some counterclockwise rotation of Italy; hence the faults in the Tyrrhenian Sea slip both parallel to the shoreline and perpendicular to it.

The surface rock in the Anti-Apennines was deposited on the floor of Tethys Sea during the Jurassic and Cretaceous of the Mesozoic. This lighter calcareous rock rides over the front of the subduction zone, uplifted by compressional and isostatic forces. Just behind it is a zone of crustal thinning caused by extensional forces; i.e., the subduction and the rotation cause a wave of compression with a peak under the Anti-Apennines and a valley in the Tyrrhenian Sea. The result is a karst-graben or half-graben landform with the Volscian Mountains as karst and the coastal chain of Pontine marshes, South Pontine marsh, Terracina Basin, Gaeta Basin and Volturno Basin as graben.

This landform began to appear in the Messinian stage of the Miocene, about 7.2 to 5.3 million years ago. It went on to mature in the Pliocene. Also in this time volcanic activity associated with the faults and the weakening of the crust over the subduction created the volcanic zones of Latium and Campania, which intruded into the karst-graben, mainly on the karst side. In the Pleistocene the basins slowly filled with sediment from the weak run-off of the mountains, accelerating with the deforestation of modern times.

Ecology

Fauna

Of the Amphibians, Urodela are found at around 557 m (1,827 ft) and Anura at around 314 m (1,030 ft) in vernal pools, springs and wells. The salamanders are Salamandrina perspicillata, Triturus carnifex, Lissotriton italicus and Lissotriton vulgaris; the frogs are Bufo bufo, Bufo viridis, Hyla intermedia and Rana italica.

Radioactive pollution of the lower Garigliano

The Garigliano Nuclear Power Plant was constructed from 1959 to 1963 by General Electric on the Garigliano River, the water of which they used for cooling, on the border of the Monti Aurunci. It was intended to provide electrical power to the region. After several accidental releases of radioactive gas and water the plant ceased operation in 1978 but continued to be used as a storage facility for radioactive waste, which was stored under the plant. Subsequent flooding carried the waste downstream into the Gulf of Gaeta. The effect on the ecology was toxic. One study reports:

In fact the genetic damage observed in studies performed with the micronucleus test applied on wild rodents from the Piana del Garigliano resulted among the highest recorded in Italy.

Additional studies were unable to tie anomalies of the skull and teeth in the area's rodents to contamination from the power plant; maybe they are attributable to a naturally high radiational level caused by the volcanic intrusions in the rock. The lower Garigliano remains sparsely populated.

See also

• Geography of Italy