Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/20215
Share/Export:
logo share SHARE logo core CORE BASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE

Invite to open peer review
Title

The “Pomici di mercato” Plinian eruption of Somma-Vesuvius: magma chamber processes and eruption dynamics

AuthorsAulinas, M.; Civetta, L.; Di Vito, Mauro; Orsi, G.; Gimeno, D.; Fernandez-Turiel, J. L. CSIC ORCID
KeywordsVesuvius
Pomici di Mercato eruption
Magma chamber
Radiogenic isotopes
Issue DateNov-2007
PublisherSpringer Nature
CitationBulletin of Volcanology 70(7): 825-840 (2007)
AbstractThe Pomici di Mercato (PdM, 8,010 ± 40 a), also known in the literature as Pomici Gemelle or Pomici di Ottaviano, is one of the oldest Plinian eruptions of Somma-Vesuvius. This eruption occurred after the longest (7 ka) quiescence period of the volcano and was followed by more than 4 ka of repose. The erupted magma is phonolitic in composition. All the products have very low phenocrysts content (less than 3%) and show evidence of mineralogical disequilibria. They contain K-feldspar ± clinopyroxene (salite and diopside) ± plagioclase ± garnet ± biotite ± amphibole ± apatite ± Fe-Ti oxides. Pumice fragments collected at different stratigraphic heights are slightly less evolved and more enriched in radiogenic Sr composition upsection. The glass composition is fairly homogeneous in single pumice fragment and among pumice fragments from different layers. Glass separated from pumice fragments collected at different stratigraphic heights is homogeneous in the Sr-isotope composition (around a value of 0.70717). Glass is in isotopic equilibrium with salite throughout the entire sequence and with diopside at the base of the sequence. Diopside becomes more radiogenic upsection, reaching a value of 0.707458 ± 7, whereas feldspar is consistently slightly less radiogenic than glass. Nd-isotope composition is fairly uniform (ca. 0.51247) through the whole sequence. The isotopic disequilibria among glass, feldspar and diopside, together with the homogeneous isotopic composition of pumice glass in equilibrium with salite, and the mineralogical disequilibria between plagioclase and K-feldspar, imply that most of the diopside and plagioclase crystals are xenocrysts incorporated into the phonolitic magma during residence in a magma chamber and/or during ascent towards the surface. The PdM Tephra are compositionally and isotopically similar to the phonolitic, first-erupted products of the subsequent Pomici di Avellino Plinian eruption. On the basis of this similarity, we suggest that the magma feeding both eruptions resulted from the tapping of a unique magma chamber. Prior to the PdM eruption, this chamber was formed by a large and homogeneous phonolitic magma body. After the PdM eruption, as a consequence of new arrivals of more radiogenic in Sr, less-differentiated magma batches, the magma chamber progressively developed a slightly stratified phonolitic uppermost portion, capping a tephriphonolitic layer, both emitted during the subsequent Pomici di Avellino eruption.
Description16 páginas, 10 figuras, 6 tablas.
Publisher version (URL)http://www.springerlink.com/content/05873446053637xx/fulltext.html
URIhttp://hdl.handle.net/10261/20215
DOI10.1007/s00445-007-0172-z
ISSN0258-8900
Appears in Collections:(Geo3Bcn) Artículos

Show full item record

CORE Recommender

SCOPUSTM   
Citations

33
checked on Mar 25, 2024

WEB OF SCIENCETM
Citations

31
checked on Feb 23, 2024

Page view(s)

679
checked on Mar 28, 2024

Google ScholarTM

Check

Altmetric

Altmetric


WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.