Publication Date:
2017-04-04
Description:
New geochemical and Sr-isotope data have been acquired on samples representative of volcanic units erupted inside the
resurgent Campi Flegrei caldera CFc. over the past 12 ka. These data, integrated with previous published petrological, and
with newly acquired geochronological, volcanological and geothermal data, shed light on the nature and timing of the
processes that controlled the evolution of the Phlegraean magmatic system. In the past 12 ka, three isotopically and
geochemically distinct magmatic components were erupted at the CFc as either homogeneous or mixed magma batches. One
component, Campanian Ignimbrite component CIc. 87Srr86Srs0.70735–0.70740., is similar to the trachytic magma
extruded during the first phase of the Campanian Ignimbrite CI. eruption 37 ka.. A second component, Neapolitan Yellow
Tuff component NYTc. 87Srr86Srs0.70750–0.70757., is similar to the latitic–alkali–trachytic magma batches extruded
during the course of the Neapolitan Yellow Tuff NYT. eruption 12 ka.. A third component, Minopoli component MIc.
87Srr86Srf0.7086., is similar to the trachybasaltic magma of the Minopoli 2 MI. eruption 9.7 ka.. These components
were erupted as either single batches of magma, or mixed CI–NYT or MI–NYT batches of magma, through vents located
either along the structural boundary of the NYT caldera or inside the NYT caldera, mainly on portions of the resurgent block
under extensional stress. The CI and NYT components represent residual portions of older, large-volume magma reservoirs
which have fed eruptions since about 60 and 15 ka, respectively. The least-evolved MI component was erupted only during
the 12–9.5 ka and 8.6–8.2 ka epochs of activity, through vents located on a NE–SW regional fault system. This component
could represent a deeper reservoir tapped by the NE–SW regional fault system reactivated after the NYT caldera collapse.
Deeper MI and shallower CI and NYT magmatic systems interacted by mixing among batches of magma during their rise to
surface. Overall, the data suggest that the CFc magmatic system today is characterized by the presence of two larger,
independent reservoirs, filled by residual portions of the CI and NYT magmas. These generated many smaller, shallower
pockets of evolved magma, that fed most of the eruptions that occurred in the CFc over the past 12 ka. Moreover, a deeper
reservoir MI., tapped by the NE–SW regional fault system, provided batches of less-evolved magma that mixed with
magma present in the shallower pockets. q1999 Elsevier Science B.V. All rights reserved.
Description:
Published
Description:
247–268
Description:
1V. Storia e struttura dei sistemi vulcanici
Description:
JCR Journal
Description:
restricted
Keywords:
Campi Flegrei caldera
;
magmatic system
;
isotopic disequilibrium
;
magma mixing
;
04. Solid Earth::04.08. Volcanology::04.08.99. General or miscellaneous
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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