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Monte Vulture volcano, Italy


volcano number: none (not Holocene, therefore not catalogued in Volcanoes of the World)

summit elevation: 1326 m

location: XXXXX°N, XXXXX°E


The following is summarized from Guest et al. (1988), Crisci et al. (1983) and La Volpe & Principe (1991); there is no first-hand information about this volcano available for the moment.

Distant image of Vulture volcano from the north, taken on 3 May 1996. The strongly dissected outer flank of the volcano is visible, a central edifice can be discerned to the right of the summit.

Monte Vulture, with a summit elevation of 1326 m, is peculiar for being the only of the major volcanoes on the Italian peninsula lying to the east of the Apennine chain, and for the occurrence of the mineral hauyne in its lavas. Although there are recent volcanological studies of the volcano, it remains relatively poorly known, also because it lies far from the major touristic areas of Italy.

Vulture is a complex strato-volcano with several eccentric eruptive centers. The summit area is occupied by a caldera-like structure (Valle dei Grigi) whose origin has been subject of debate (Guest et al. 1988, La Volpe & Principe 1991). The Valle dei Grigi depression is open to the SW, with a slightly eccentric post-caldera (assuming that there is indeed a caldera) edifice lying on its SSW boundary.

Two younger calderas are present on that edifice, of the older of which (Piano Comune/Serra Corta caldera) only the W rim is still preserved. The younger caldera (named Monticchio caldera) has about 3 km maximum diameter and contains the most recent eruptive centers of the volcano, the water-filled Monticchio maar craters.

Geological map of Monte Vulture, taken from La Volpe & Principe (1991).

The geological history of Vulture volcano has been reconstructed by Crisci et al. (1983), La Volpe et al. (1984), Guest et al. (1988) and La Volpe & Principe (1991). Three major phases in the evolution have been identified by Guest et al. (1988).
1) The "Basal" phase: during its first stage the activity was characterized by violent ignimbrite-forming eruptions (eruption of ignimbrites A and B) emitting trachytic magmas. This stage was dated at about 1 Ma ago. Outcrops of the ignimbrites exist only in the marginal NW and NE sectors of the volcano. Following the ignimbrite eruptions, lava domes of hauyne-bearing latites and trachytes were extruded. Parts of the domes were successively destroyed by renewed explosive activity. This activity occurred about 830 ka ago.
2) The cone-building phase began with renewed violently explosive eruptions producing Plinian fall deposits and ignimbrites (Barile-Rionero tephra or "tufi chiari"). Lava effusion also took part in the construction of the strato-volcano, and vast alluvial fans formed around the cone, manily on its E and SE slopes. Later activity produced the "tufi scuri" which are a series of dark-colored pyroclastic beds alternating with paleosols indicating periods of volcanic quiescence. Chemically, the lavas became more undersaturated and alkali-rich (tephrites and foidites), and the activity in general was more effusive. Products of this period have been dated at ca. 500 ka.
Renewed explosive activity accompanied or preceded what Guest et al. (1988) interpret as the collapse of the Valle dei Grigi caldera. Indeed, these authors postulate a sector collapse origin for the depression, similar to the collapse of Mount St. Helens, with formation of a debris avalanche whose deposits, however, are no longer present due to the vigorous erosive activity of the Ofanto river on the W side of the volcano. La Volpe and Principe dispute a calderic origin of the Valle dei Grigi and interpret the depression as a result "from the superimposition of two different factors: the crater area of the Monte Vulture-S. Michele composite volcano and the western branch of a fault, carved and widened by erosion."
3) The latest phase, named "post-caldera" by Guest et al. (1988), was characterized by the eruption of lava flows and domes in the Valle dei Grigi depression, and the formation of the two aforementioned calderas on the most recent volcanic edifice. As recently as 40 ka ago, powerful hydromagmatic explosions blew out the maars now filled with the Laghi di Monticchio. These eruptions produced wet surges that were confined to a radius of 2 km from the vents.

References:

Crisci G, de Fino M, La Volpe L & Rapisardi L (1983) Pleistocene ignimbrites of Monte Vulture (Basilicata, Southern Italy). Neues Jahrbuch füer Geologie und Paläontologie Monatshefte 12: 731-746.

Guest JE, Duncan AM & Chester DK (1988) Monte Vulture Volcano (Basilicata, Italy): an analysis of morphology and volcaniclastic facies. Bulletin of Volcanology 50: 244-257.

La Volpe L, Patella D, Rapisardi L & Tramacere A (1984) The evolution of the Monte Vulture volcano (Southern Italy): inferences from volcanological, geological and deep dipole electrical soundins data. Journal of Volcanology an Geothermal Research 22: 147-162.

La Volpe L & Principe C (1991) Comments on Guest et al. (1988) and Reply by Guest et al.. Bulletin of Volcanology 53: 222-229.

Page set up on 24 June 1996, last modified on 26 June 1996