Publikationsdatum:
2022-04-22
Beschreibung:
We describe the diagnostic lithological and chemical features of distal tephras from major MiddleLate Pleistocene (560e36 ka) explosive eruptions of the Colli Albani volcanic district, central Italy.
In particular, we explore the time-dependent variability of the Sr and Nd isotope compositions as
a tool for recognising and pinpointing individual Colli Albani tephra in distal settings. The distal
tephras investigated are in lacustrine and fluvial sediments of central Apennine intermountain basins
located 70 kme100 km east of Colli Albani. The recognition of the Colli Albani tephras is essentially
based on the K-foiditic composition of their glass, which, within the Italian volcanological framework,
is a distinctive character of the Colli Albani pyroclasts. In detail, these tephras are attributed to the
following eruptive units: Tufo Pisolitico di Trigoria (561 2 ka); Tufo del PalatinoeTufo di Bagni
Albule (530 2/527 2 ka), Tufo di Bagni AlbuleePozzolane Rosse air-fall sequence (517 1
to 500 3 ka), Pozzolane Rosse (457 4 ka), Villa Senni (365 4 ka), and Albano 5e7 (41 7 to
36 1 ka). These correlations are supported by 40Ar/39Ar dating of the distal tephras correlated to the
Pozzolane Rosse (457.4 1.7 ka), Villa Senni (365 2 ka) and Albano 5e7 (41 9 ka) and by 87Sr/86Sr
measured on clinopyroxene crystals and fresh glassy scoria from distal Colli Albani tephras that range
from w0.711 to w0.709. These ratios are similar to those that characterise the individual proximal
correlative units, and show the same decreasing trend over time. In contrast, the 143Nd/144Nd ratios
for proximal and distal bulk samples and clinopyroxene increase from w0.51212 to w0.51215 from
the oldest to the youngest tephra deposit. In summary, the study of Sr and Nd isotope compositions
that is here applied on products from the Colli Albani volcanic district is a powerful, complementary
tool to the more traditional tephrostratigraphic methods (e.g., componentry and electron microprobe
analysis) for fingerprinting of distal tephras over a large region of the central Mediterranean, and over
a large time interval, such as from 560 ka to 36 ka.
Beschreibung:
Published
Beschreibung:
190-206
Beschreibung:
2V. Struttura e sistema di alimentazione dei vulcani
Beschreibung:
3V. Proprietà chimico-fisiche dei magmi e dei prodotti vulcanici
Beschreibung:
4V. Processi pre-eruttivi
Beschreibung:
JCR Journal
Schlagwort(e):
Ultra-potassic tephra markers
;
Roman Comagmatic Province
;
Major elements glass compositions
;
Isotopic 87Sr/86Sr and 143Nd/144Nd
Repository-Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Materialart:
article
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