Publication Date:
2017-04-04
Description:
Following the 2001 and 2002–2003 flank eruptions,
activity resumed at Mt. Etna on 7 September 2004
and lasted for about 6 months. This paper presents new
petrographic, major and trace element, and Sr–Nd isotope
data from sequential samples collected during the entire
2004–2005 eruption. The progressive change of lava
composition allowed defining three phases that correspond
to different processes controlling magma dynamics inside
the central volcano conduits. The compositional variability
of products erupted up to 24 September is well reproduced
by a fractional crystallization model that involves magma
already stored at shallow depth since the 2002–2003
eruption. The progressive mixing of this magma with a
distinct new one rising within the central conduits is clearly
revealed by the composition of the products erupted from
24 September to 15 October. After 15 October, the
contribution from the new magma gradually becomes
predominant, and the efficiency of the mixing process ensures the emission of homogeneous products up to the end
of the eruption. Our results give insights into the complex
conditions of magma storage and evolution in the shallow
plumbing system of Mt. Etna during a flank eruption.
Furthermore, they confirm that the 2004–2005 activity at
Etna was triggered by regional movements of the eastern
flank of the volcano. They caused the opening of a complex
fracture zone extending ESE which drained a magma stored
at shallow depth since the 2002–2003 eruption. This process
favored the ascent of a different magma in the central
conduits, which began to be erupted on 24 September
without any significant change in eruptive style, deformation,
and seismicity until the end of eruption.
Description:
Published
Description:
781–793
Description:
2.3. TTC - Laboratori di chimica e fisica delle rocce
Description:
JCR Journal
Description:
reserved
Keywords:
Geochemistry
;
Isotopic compositions
;
Magma feeding system
;
Magma mixing
;
Mt. Etna
;
04. Solid Earth::04.08. Volcanology::04.08.03. Magmas
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
