Abstract
A supereruption that occurred in the Campi Flegrei area, Italy, ca.
39 ka had regional- and global-scale environmental impacts and deposited
the Campanian Ignimbrite (CI). We attempt to shed light on critical
aspects of the eruption (depth of magma chamber, intensive pre-eruptive
magma conditions) and the large-volume magma plumbing system on the
basis of information derived from analyzing melt inclusion (MI) data.
To achieve these aims, we provide new measurements of homogenization
temperatures and values of dissolved H2O within phenocryst-hosted
MIs from pumices erupted during different phases of the CI eruption.
The MI data indicate that a relatively homogeneous overheated trachytic
magma resided within a relatively deep magma chamber. Dissolved water
contents in MIs indicate that prior to the eruption the magma chamber
underwent radical changes related to differential upward movement
of magma. Decompression of the rising trachytic magma caused a decrease
in water solubility and crystallization, and trachytic bodies were
emplaced at very shallow depths. The proposed eruptive model links
portions of the main magma chamber and apophyses with specific eruptive
units.
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