Timescales of magmatic processes prior to the ∼4.7 ka Agnano-Monte Spina eruption (Campi Flegrei caldera, Southern Italy) based on diffusion chronometry from sanidine phenocrysts

Year:

2017

Type of Publication:

Artikel

Autoren:

Iovine, Raffaella Silvia; Fedele, Lorenzo; Mazzeo, Fabio Carmine; Arienzo, Ilenia; Cavallo, Andrea; Wörner, Gerhard; Orsi, Giovanni; Civetta, Lucia; D', Massimo; Antonio,

Journal:

Bulletin of Volcanology

Volume:

79

Nummer:

2

Seiten:

18

Monat:

Januar

ISSN:

1432-0819

BibTex:

@article{Iovine2017, author = "Raffaella Silvia Iovine and Lorenzo Fedele and Fabio Carmine Mazzeo and Ilenia Arienzo and Andrea Cavallo and Gerhard W{\"o}rner and Giovanni Orsi and Lucia Civetta and Massimo D{\&}#039 and Antonio", abstract = "Barium diffusion chronometry applied to sanidine phenocrysts from the trachytic Agnano-Monte Spina eruption (∼4.7 ka) constrains the time between reactivation and eruption of magma batches in the Campi Flegrei caldera. Backscattered electron imaging and quantitative electron microprobe measurements on 50 sanidine phenocrysts from representative pumice samples document core-to-rim compositional zoning. We focus on compositional breaks near the crystal rims that record magma mixing processes just prior to eruption. Diffusion times were modeled at a magmatic temperature of 930 {\textdegree}C using profiles based on quantitative BaO point analyses, X-ray scans, and grayscale swath profiles, yielding times ≤60 years between mixing and eruption. Such short timescales are consistent with volcanological and geochronological data that indicate that at least six eruptions occurred in the Agnano-San Vito area during few centuries before the Agnano-Monte Spina eruption. Thus, the short diffusion timescales are similar to time intervals between eruptions. Therefore, the rejuvenation time of magma residing in a shallow reservoir after influx of a new magma batch that triggered the eruption, and thus pre-eruption warning times, may be as short as years to a few decades at Campi Flegrei caldera.", day = "24", doi = "10.1007/s00445-017-1101-4", issn = "1432-0819", journal = "Bulletin of Volcanology", month = "Jan", number = "2", pages = "18", title = "{T}imescales of magmatic processes prior to the ∼4.7 ka {A}gnano-{M}onte {S}pina eruption ({C}ampi {F}legrei caldera, {S}outhern {I}taly) based on diffusion chronometry from sanidine phenocrys", url = "https://doi.org/10.1007/s00445-017-1101-4", volume = "79", year = "2017", }

Kurzzusammenfassung:

Barium diffusion chronometry applied to sanidine phenocrysts from the trachytic Agnano-Monte Spina eruption (∼4.7 ka) constrains the time between reactivation and eruption of magma batches in the Campi Flegrei caldera. Backscattered electron imaging and quantitative electron microprobe measurements on 50 sanidine phenocrysts from representative pumice samples document core-to-rim compositional zoning. We focus on compositional breaks near the crystal rims that record magma mixing processes just prior to eruption. Diffusion times were modeled at a magmatic temperature of 930 {\textdegree}C using profiles based on quantitative BaO point analyses, X-ray scans, and grayscale swath profiles, yielding times ≤60 years between mixing and eruption. Such short timescales are consistent with volcanological and geochronological data that indicate that at least six eruptions occurred in the Agnano-San Vito area during few centuries before the Agnano-Monte Spina eruption. Thus, the short diffusion timescales are similar to time intervals between eruptions. Therefore, the rejuvenation time of magma residing in a shallow reservoir after influx of a new magma batch that triggered the eruption, and thus pre-eruption warning times, may be as short as years to a few decades at Campi Flegrei caldera.