Composition and origin of nodules from the =20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma - Vesuvius, Italy

Rita Klébesz, Robert J. Bodnar, Benedetto De Vivo, K. Török, Annamaria Lima, Paola Petrosino

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Nodules (coarse-grain "plutonic" rocks) were collected from the ca. 20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma-Vesuvius, Italy. The nodules are classified as monzonite-monzogabbro based on their modal composition. The nodules have porphyrogranular texture, and consist of An-rich plagioclase, K-feldspar, clinopyroxene (ferroan-diopside), mica (phlogopite-biotite) ± olivine and amphibole. Aggregates of irregular intergrowths of mostly alkali feldspar and plagioclase, along with mica, Fe-Ti-oxides and clinopyroxene, in the nodules are interpreted as crystallized melt pockets. Crystallized silicate melt inclusions (MI) are common in the nodules, especially in clinopyroxenes. Two types of MI have been identified. Type I consists of mica, Fe-Ti-oxides and/or dark green spinel, clinopyroxene, feldspar and a vapor bubble. Volatiles (CO2, H2O) could not be detected in the vapor bubbles by Raman spectroscopy. Type II inclusions are generally lighter in color and contain subhedral feldspar and/or glass and several opaque phases, most of which are confirmed to be oxide minerals by SEM analysis. Some of the opaque-appearing phases that are below the surface may be tiny vapor bubbles. The two types of MI have different chemical compositions. Type I MI are classified as phono-tephrite - tephri-phonolite - basaltic trachy-andesite, while Type II MI have basaltic composition. The petrography and MI geochemistry led us to conclude that the nodules represent samples of the crystal mush zone in the active plumbing system of Mt. Somma-Vesuvius that were entrained into the upwelling magma during the PB-Sarno eruption.

Original languageEnglish
Pages (from-to)324-337
Number of pages14
JournalCentral European Journal of Geosciences
Volume4
Issue number2
DOIs
Publication statusPublished - Jun 2012

Fingerprint

melt inclusion
volcanic eruption
mica
clinopyroxene
bubble
feldspar
oxide
plagioclase
phonolite
monzonite
alkali feldspar
silicate melt
plutonic rock
Raman spectroscopy
phlogopite
diopside
petrography
andesite
spinel
amphibole

Keywords

  • Crystal mush zone
  • Melt inclusions
  • Mt. Somma-Vesuvius
  • Nodules

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

Cite this

Composition and origin of nodules from the =20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma - Vesuvius, Italy. / Klébesz, Rita; Bodnar, Robert J.; Vivo, Benedetto De; Török, K.; Lima, Annamaria; Petrosino, Paola.

In: Central European Journal of Geosciences, Vol. 4, No. 2, 06.2012, p. 324-337.

Research output: Contribution to journalArticle

Klébesz, Rita ; Bodnar, Robert J. ; Vivo, Benedetto De ; Török, K. ; Lima, Annamaria ; Petrosino, Paola. / Composition and origin of nodules from the =20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma - Vesuvius, Italy. In: Central European Journal of Geosciences. 2012 ; Vol. 4, No. 2. pp. 324-337.
@article{6fa9531aa1274fc6ad234e6665ba76ea,
title = "Composition and origin of nodules from the =20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma - Vesuvius, Italy",
abstract = "Nodules (coarse-grain {"}plutonic{"} rocks) were collected from the ca. 20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma-Vesuvius, Italy. The nodules are classified as monzonite-monzogabbro based on their modal composition. The nodules have porphyrogranular texture, and consist of An-rich plagioclase, K-feldspar, clinopyroxene (ferroan-diopside), mica (phlogopite-biotite) ± olivine and amphibole. Aggregates of irregular intergrowths of mostly alkali feldspar and plagioclase, along with mica, Fe-Ti-oxides and clinopyroxene, in the nodules are interpreted as crystallized melt pockets. Crystallized silicate melt inclusions (MI) are common in the nodules, especially in clinopyroxenes. Two types of MI have been identified. Type I consists of mica, Fe-Ti-oxides and/or dark green spinel, clinopyroxene, feldspar and a vapor bubble. Volatiles (CO2, H2O) could not be detected in the vapor bubbles by Raman spectroscopy. Type II inclusions are generally lighter in color and contain subhedral feldspar and/or glass and several opaque phases, most of which are confirmed to be oxide minerals by SEM analysis. Some of the opaque-appearing phases that are below the surface may be tiny vapor bubbles. The two types of MI have different chemical compositions. Type I MI are classified as phono-tephrite - tephri-phonolite - basaltic trachy-andesite, while Type II MI have basaltic composition. The petrography and MI geochemistry led us to conclude that the nodules represent samples of the crystal mush zone in the active plumbing system of Mt. Somma-Vesuvius that were entrained into the upwelling magma during the PB-Sarno eruption.",
keywords = "Crystal mush zone, Melt inclusions, Mt. Somma-Vesuvius, Nodules",
author = "Rita Kl{\'e}besz and Bodnar, {Robert J.} and Vivo, {Benedetto De} and K. T{\"o}r{\"o}k and Annamaria Lima and Paola Petrosino",
year = "2012",
month = "6",
doi = "10.2478/s13533-011-0059-6",
language = "English",
volume = "4",
pages = "324--337",
journal = "Open Geosciences",
issn = "2391-5447",
publisher = "Walter de Gruyter GmbH & Co. KG",
number = "2",

}

TY - JOUR

T1 - Composition and origin of nodules from the =20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma - Vesuvius, Italy

AU - Klébesz, Rita

AU - Bodnar, Robert J.

AU - Vivo, Benedetto De

AU - Török, K.

AU - Lima, Annamaria

AU - Petrosino, Paola

PY - 2012/6

Y1 - 2012/6

N2 - Nodules (coarse-grain "plutonic" rocks) were collected from the ca. 20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma-Vesuvius, Italy. The nodules are classified as monzonite-monzogabbro based on their modal composition. The nodules have porphyrogranular texture, and consist of An-rich plagioclase, K-feldspar, clinopyroxene (ferroan-diopside), mica (phlogopite-biotite) ± olivine and amphibole. Aggregates of irregular intergrowths of mostly alkali feldspar and plagioclase, along with mica, Fe-Ti-oxides and clinopyroxene, in the nodules are interpreted as crystallized melt pockets. Crystallized silicate melt inclusions (MI) are common in the nodules, especially in clinopyroxenes. Two types of MI have been identified. Type I consists of mica, Fe-Ti-oxides and/or dark green spinel, clinopyroxene, feldspar and a vapor bubble. Volatiles (CO2, H2O) could not be detected in the vapor bubbles by Raman spectroscopy. Type II inclusions are generally lighter in color and contain subhedral feldspar and/or glass and several opaque phases, most of which are confirmed to be oxide minerals by SEM analysis. Some of the opaque-appearing phases that are below the surface may be tiny vapor bubbles. The two types of MI have different chemical compositions. Type I MI are classified as phono-tephrite - tephri-phonolite - basaltic trachy-andesite, while Type II MI have basaltic composition. The petrography and MI geochemistry led us to conclude that the nodules represent samples of the crystal mush zone in the active plumbing system of Mt. Somma-Vesuvius that were entrained into the upwelling magma during the PB-Sarno eruption.

AB - Nodules (coarse-grain "plutonic" rocks) were collected from the ca. 20 ka Pomici di Base (PB)-Sarno eruption of Mt. Somma-Vesuvius, Italy. The nodules are classified as monzonite-monzogabbro based on their modal composition. The nodules have porphyrogranular texture, and consist of An-rich plagioclase, K-feldspar, clinopyroxene (ferroan-diopside), mica (phlogopite-biotite) ± olivine and amphibole. Aggregates of irregular intergrowths of mostly alkali feldspar and plagioclase, along with mica, Fe-Ti-oxides and clinopyroxene, in the nodules are interpreted as crystallized melt pockets. Crystallized silicate melt inclusions (MI) are common in the nodules, especially in clinopyroxenes. Two types of MI have been identified. Type I consists of mica, Fe-Ti-oxides and/or dark green spinel, clinopyroxene, feldspar and a vapor bubble. Volatiles (CO2, H2O) could not be detected in the vapor bubbles by Raman spectroscopy. Type II inclusions are generally lighter in color and contain subhedral feldspar and/or glass and several opaque phases, most of which are confirmed to be oxide minerals by SEM analysis. Some of the opaque-appearing phases that are below the surface may be tiny vapor bubbles. The two types of MI have different chemical compositions. Type I MI are classified as phono-tephrite - tephri-phonolite - basaltic trachy-andesite, while Type II MI have basaltic composition. The petrography and MI geochemistry led us to conclude that the nodules represent samples of the crystal mush zone in the active plumbing system of Mt. Somma-Vesuvius that were entrained into the upwelling magma during the PB-Sarno eruption.

KW - Crystal mush zone

KW - Melt inclusions

KW - Mt. Somma-Vesuvius

KW - Nodules

UR - http://www.scopus.com/inward/record.url?scp=84864880739&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84864880739&partnerID=8YFLogxK

U2 - 10.2478/s13533-011-0059-6

DO - 10.2478/s13533-011-0059-6

M3 - Article

AN - SCOPUS:84864880739

VL - 4

SP - 324

EP - 337

JO - Open Geosciences

JF - Open Geosciences

SN - 2391-5447

IS - 2

ER -