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Mamma
Etna's countless children |
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Monte
Pizzillo is a large pyroclastic cone in the upper portion of the Northeast
Rift that possibly formed around A.D. 970 (Tanguy et al., 1999) but was
affected by at least one major eruption in more recent time and furthermore
is strongly faulted. Its morphology is thus quite irregular and makes
it easily recognizable when seen from a distance. While the cone itself
is not particularly tall (it rises approximately 40 m above its south
base), it sits on elevated terrain making up the crest of the Northeast
Rift and therefore forms a prominent landmark. A poorly defined summit
crater forms a shallow depression at the top of the cone, but on its northern,
northeastern and eastern flanks there are three much larger and more recent
craters. The two latter of these almost certainly formed during an unusually
explosive eruption in 1879, while the age of the third is not well constrained
(although it may have also formed during the 1879 eruption, judging from
its morphology and lack of an 1879 pyroclastic cover). These craters have
destroyed a portion of the older Monte Pizzillo, which furthermore has
suffered strong deformation due to faulting post-dating its formation.
Two conspicuous sets of faults are well exposed on the south flank of
the cone, the more pronounced following the trend of the Northeast Rift
(approximately N35°E), while the second has a more easterly trend
and is less strongly expressed. Such faults are known to form during the
propagation of dikes along the axis of the rift, as has been well observed
during the 2002 eruption on the same rift. However, the different character
of the two sets of faults indicates that they were formed during two distinct
events. The more strongly expressed NNE-SSW faults have the downthrown
block on their eastern side, whereas the NE-SW system has downthrow on
its NW side. If these fault systems are hypothetically linked to the formation
of the more recent craters on the northern, northeastern and eastern sides
of Monte Pizzillo, the NNE-SSW set is associated with the 1879 craters
and the NE-SW faults with the crater on the north flank of the cone. |
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Copyright © Boris Behncke, "Italy's Volcanoes: The Cradle of Volcanology" |
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Page set up on 23 February 2004 |