Publication Date:
2017-04-04
Description:
Geological surveys, tephrostratigraphic study,
and 40Ar/39Ar age determinations have allowed us to
chronologically constrain the geological evolution of the
lower NW flank of Etna volcano and to reconstruct the
eruptive style of the Mt Barca flank eruption. This
peripheral sector of the Mt Etna edifice, corresponding to
the upper Simeto valley, was invaded by the Ellittico
volcano lava flows between 41 and 29 ka ago when the Mt
Barca eruption occurred. The vent of this flank eruption is
located at about 15 km away from the summit craters, close
to the town of Bronte. The Mt Barca eruption was
characterized by a vigorous explosive activity that produced
pyroclastic deposits dispersed eastward and minor effusive
activity with the emission of a 1.1-km-long lava flow.
Explosive activity was characterized by a phreatomagmatic
phase followed by a magmatic one. The geological setting
of this peripheral sector of the volcano favors the
interaction between the rising magma and the shallow
groundwater hosted in the volcanic pile resting on the
impermeable sedimentary basement. This process produced phreatomagmatic activity in the first phase of the eruption,
forming a pyroclastic fall deposit made of high-density,
poorly vesicular scoria lapilli and lithic clasts. Conversely,
during the second phase, a typical strombolian fall deposit
formed. In terms of hazard assessment, the possible
occurrence of this type of highly explosive flank eruption,
at lower elevation in the densely inhabited areas, increases
the volcanic risk in the Etnean region and widens the
already known hazard scenario.
Description:
INGV-DPC V3_6 project UR V3_6/07
Description:
In press
Description:
on line first
Description:
3.5. Geologia e storia dei sistemi vulcanici
Description:
JCR Journal
Description:
reserved
Keywords:
Etna volcano
;
unconformity
;
tephostratigraphy
;
40Ar/39Ar age determination
;
04. Solid Earth::04.04. Geology::04.04.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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