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Titel |
Bio-chemostratigraphy of the Barremian-Aptian shallow-water carbonates of the southern Apennines (Italy): pinpointing the OAE1a in a Tethyan carbonate platform |
VerfasserIn |
M. Lucia, A. Trecalli, M. Mutti, M. Parente |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1869-9510
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Digitales Dokument |
URL |
Erschienen |
In: Solid Earth ; 3, no. 1 ; Nr. 3, no. 1 (2012-01-27), S.1-28 |
Datensatznummer |
250000832
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Publikation (Nr.) |
copernicus.org/se-3-1-2012.pdf |
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Zusammenfassung |
Low biostratigraphic resolution and lack of chronostratigraphic calibration
hinder precise correlations between platform carbonates and coeval
deep-water successions. These are the main obstacle when studying the record
of Mesozoic oceanic anoxic events in carbonate platforms. In this paper
carbon and strontium isotope stratigraphy are used to produce the first
chronostratigraphic calibration of the Barremian-Aptian biostratigraphy of
the Apenninic carbonate platform of southern Italy. According to this
calibration, the segment of decreasing δ13C values, leading to
the negative peak that is generally taken as the onset of the Selli event,
starts a few metres above the last occurrence of Palorbitolina lenticularis and Voloshinoides murgensis. The following rise
of δ13C values, corresponding to the interval of enhanced
accumulation of organic matter in deep-water sections, ends just below the
first acme of Salpingoporella dinarica, which roughly corresponds to the segment of peak δ13C values. The whole carbon isotope excursion associated with the
oceanic anoxic event 1a is bracketed in the Apenninic carbonate platform
between the last occurrence of Voloshinoides murgensis and the "Orbitolina level", characterized by
the association of Mesorbitolina parva and Mesorbitolina texana. Since these bioevents have been widely recognized
beyond the Apenninic platform, the calibration presented in this paper can
be used to pinpoint the interval corresponding to the Early Aptian oceanic
anoxic event in other carbonate platforms of central and southern Tethys.
This calibration will be particularly useful to interpret the record of the
Selli event in carbonate platform sections for which a reliable carbon
isotope stratigraphy is not available. |
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