MT. VESUVIUS
Mt. Vesuvius is the most famous volcano in Europe (see photos of volcano &
historic eruptions). It has erupted on a semi-regular basis over the
last 2000 years. Vesuvius is a ~300,000 year old subduction zone
stratovolcano located just east of the major Italian city of Naples, coastal
Campania, southern Italy.
The most famous Vesuvius eruption occurred on 24-25
August, 79 A.D. An enormous ash eruption and collapsing ash column destroyed
and buried three Roman towns (Pompeii, Herculaneum, and Stabiae). A
written eyewitness account of the eruption has survived. Pompeii has been
extensively excavated by archaeologists since its discovery in the
mid-1700s. It is widely considered to be the most significant
archaeological site on Earth. Pompeii is rarely mentioned in ancient
historical records, but historians & archaeologists understand Pompeii
better than Rome itself in many ways. The most famous Pompeii discoveries
are casts of people (& animals) preserved in the volcanic deposits.
The casts are empty spaces in the ash & pumice. They have been filled
with plaster & the matrix subsequently removed. Expressions of pain
& anguish can still be seen preserved on some of the Romans’ faces. (see plaster casts
of Romans in Pompeii - scroll down).
The rocks shown below are phonolite pumice from the
August 79 A.D. eruption that buried Pompeii. This eruption produced ash
and pumice having phonolite and tephriphonolite compositions (= alkaline,
intermediate, extrusive igneous rocks).
Phonolite pumice (air-fall deposit) from 24-25 August 79 A.D. plinian
eruption of Mt. Vesuvius. Pumice at center is 3.0 cm across. Sample
collected from the ruins of the Roman city of Pompeii (generously donated by
the Pompeii Archaeological Superintendent).
Roman victims of the 24-25 August 79 A.D. Vesuvius ash eruption at Pompeii,
Italy. These are plaster casts made from external molds of human corpses
in the ash-pumice deposit at Pompeii. (photos
by Isabell Giannetto)
Roman victims (above & below) of the 24-25 August 79 A.D. Vesuvius eruption at
Pompeii, Italy. (photos by Isabell Giannetto)
Above:
human skeletal elements are still preserved in this specimen - note the teeth
and the sutures between invidual bones of the skull.
Below:
this individual sat down and covered his mouth and nose to help prevent
suffocating in the volcanic ash - it didn’t work.
Porphyritic tephrite or phonolite from a mid-December 1631 eruption of Mt. Vesuvius.
The 1631 event was an effusive-explosive, subplinian eruption that followed 131
years of inactivity. Centimeter scale.
Air-fall lapilli from the 22-26
March 1944 eruption of Mt. Vesuvius. Lapilli refers to erupted
fragments of rock that are coarser in grain size compared with ash. Each
lapilli grain shown here is about 2 to 2.5 mm in size.
