Publication Date:
2020-12-14
Description:
In this paper, we document the evolution of the emergent Panarea dome in the Aeolian islands (Southern
Italy), placing particular emphasis on the reconstruction of the explosive events that occurred during the
final stage of its evolution. Two main pyroclastic successions exposing fall deposits with different
compositions have been studied into detail: the andesitic Palisi succession and the basaltic Punta Falcone
succession. The close-in-time deposition of the two successions, the dispersal area and grain-size distribution
of the deposits account for their attribution to vents located in the western sector of the present island and
erupting almost contemporaneously. Vents could have been aligned along NNE-trending regional fracture
systems controlling the western flank of the dome and possibly its collapse. Laboratory analyses have been
devoted to the characterization of the products of the two successions that have been ascribed to vulcanianand
to strombolian-type eruptions respectively. The vulcanian eruption started with a vent-clearing phase
that occurred by sudden decompression of a pressurized magma producing ballistic bombs and a surge blast
and the development of a vulcanian plume. Vulcanian activity was almost contemporaneous to stromboliantype
fall-out eruptions. The coeval occurrence of basaltic and andesitic eruptions from close vents and the
presence of magmatic basaltic enclaves in the final dacitic lava lobe of the dome allow us to speculate that
the intrusion of a basaltic dyke played a major role in triggering explosive eruptions. The final explosive
episodes may have been caused by extensional tectonics fracturing the roof of a zoned shallow magma
chamber or by the intrusion of a new basaltic magma into a more acidic and shallow reservoir. Intrusion most
likely occurred through the injection of dykes along the western cliff of the present Panarea Island inducing
the collapse of the western sector of the dome.
Description:
Published
Description:
797-811
Description:
JCR Journal
Description:
restricted
Keywords:
fall and flow deposits
;
subaerial–submarine domes
;
explosive activity
;
Panarea Aeolian Islands
;
04. Solid Earth::04.07. Tectonophysics::04.07.08. Volcanic arcs
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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