Ultrafast syn-eruptive degassing and ascent trigger high-energy basic eruptions.

ABSTRACT: Lithium gradients in plagioclase are capable of recording extremely short-lived processes associated with gas loss from magmas prior to extrusion at the surface. We present SIMS profiles of the ⁷Li/³⁰Si ion ratio in plagioclase crystals from products of the paroxysmal sequence that occurred in the period 2011-2013 at Mt. Etna (Italy) in an attempt to constrain the final ascent and degassing processes leading to these powerful eruptions involving basic magma. The observed Li concentrations reflect cycles of Li addition to the melt through gas flushing, and a syn-eruptive stage of magma degassing driven by decompression that finally produce significant Li depletion from the melt. Modeling the decreases in Li concentration in plagioclase by diffusion allowed determinatio

SUBMITTER: Giuffrida M 

PROVIDER: S-EPMC5760692 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature