Geochemical similarities between the Vesuvius, Phlegraean Fields and Stromboli Volcanoes: petrogenetic, geodynamic and volcanological implications |
| |
Authors: | A Peccerillo |
| |
Institution: | (1) Dipartimento di Scienze della Terra, Università di Perugia, Perugia, Italy, IT |
| |
Abstract: | Summary Vesuvius and Stromboli are two active and extensively studied volcanoes that traditionally have been considered as having
different styles of eruption, rock composition and tectonic setting. Data reveal close compositional affinities between these
two volcanoes. The abundant 13–15 Ka old Stromboli leucite-tephritic rocks have radiogenic isotope signatures, and abundances
and ratios of incompatible elements with the exception of Rb and K, which are identical to those of Vesuvius. The Phlegraean
Fields also show close affinities to these volcanoes.
The similarity between Stromboli leucite-tephrites and Vesuvius rocks cannot be the result of low pressure processes, given
the differences between the two volcanoes in terms of structural features, eruptive behaviour and type of basement rocks.
Instead, the observed geochemical signatures are likely to represent a primary magma composition and reveal a common homogeneous
source for the two suites. The higher K and Rb contents in the Vesuvius rocks suggest either selective enrichment during magma
ascent or a role for phlogopite melting during mantle anatexis.
The most primitive rocks from Vesuvius, Phlegraean Fields and Stromboli reveal intermediate compositions between arc and intraplate
volcanics. It is suggested that the mantle sources beneath these volcanoes consist of a mixture of intraplate- and slab-derived
components. Intraplate material was probably provided by inflow of asthenosheric mantle into the wedge above the subducting
Ionian Sea plate, either from the Apulian plate and/or from the Tyrrhenian Sea region. Fluids or melts released from the sinking
slab and associated sediments generated metasomatic modification of the intraplate material, whose melting gave rise to the
Stromboli, Vesuvius and Phlegraean Fields magmas.
The present study demonstrates how comparative investigations of various volcanic centres from southern Italy allow clarification
of a number of problems involving magma genesis and evolution, composition of mantle sources and geodynamic significance,
which have been long debated and are difficult to solve if individual volcanoes are considered in isolation.
Received July 20, 2000; revised version accepted March 19, 2001 |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|