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| Titel |
A multidisciplinary environmental integrated approach to better understand the Tegnue Reefs formation, offshore Chioggia, Northern Adriatic Sea. |
| VerfasserIn |
Andrea Bergamasco, Sandra Donnici, Luigi Tosi, Davide Tagliapietra, Luca Zaggia, Davide Bonaldo, Federica Braga, Cristina Da Lio, Erica Keppel, Giuliano Lorenzetti, Giorgia Manfè, Gianluca Franceschini, Otello Giovanardi, Eleonora Carol, Elena Fornaro, Carley Grant |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250098221
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| Publikation (Nr.) |
 EGU/EGU2014-13899.pdf |
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| Zusammenfassung |
| Several hard substrata cover the northwestern Adriatic shelf around 20 m depth as patchy
reefs called “Tegnue”. These submerged reefs form many discrete sets from offshore Grado
south to the Po river delta with a large field located off Chioggia. Even if the outer part of the
reef is constituted by a thick biogenic formation the underlying structure, mainly buried, is
made by cemented sand and this seems to be correlated with its origin not yet fully
understood. Different genetic interpretations have been proposed thus far, contemplating
among other cementation due to beach-rock like processes (e.g., Stefanon, 1969, Bonardi
and Tosi, 2002, Bonardi et al., 2006) or the action of ascending fluids enriched in
hydrocarbons (e.g., Gabbianelli et al., 1997, Casellato and Stefanon, 2008). An
on-going project, mainly a multidisciplinary integrated approach, combining physical,
biological, geological, geomorphological, hydrogeological and geochemical data,
supported by a detailed bathymetric mapping, an overall general circulation modeling at
high resolution, a robust geophysical evidence, and detailed underwater surveys
performed by a team of scuba-diver scientists, aims to better understand the genetic
processes backing the distribution, early genesis and evolution of such relevant
habitats.
Actually, using all the new available data, our plan is to verify which previous
interpretations on the origin of the Tegnue core better match with the diagenetic
processes that led to the cementation of the sand layers lying at the base of the organic
reefs.
Preliminary results suggest that the Tegnue reefs formed along paleochannels features
related to the former alluvial plain and submerged by the Holocene transgression. Whatever
their genesis, once exposed such rocky substrata are then quickly colonized by living
organisms, which contribute to the growth and expansion of the reef. Calcareous algae and in
general the organic concretion could have a role during the reef accretion, and benthic
invertebrates like bryozoans, mollusks, serpulids and corals also contribute to the final
building of the status of Tegnue‘s environment, but we want to demonstrate that
the in first stage of consolidation abiotic phenomena could have played a major
role.
In order to prove our thesis a series of ground water sampling as well as rock sampling
and sediment cores were carried out. The poster illustrates the overall ongoing program as
well as some work in progress and first results from field cruise.
Acknowledgments
This work was supported by the Municipality of Chioggia through the Tegnue
Project and partially by the Flagship Project RITMARE - The Italian Research for
the Sea - coordinated by the Italian National Research Council and funded by the
Italian Ministry of Education, University and Research within the National Research
Program 2011-2013, and by the Scientific Cooperation Agreement between the
CONICET (Argentina) – CNR (Italy), Program 2013–2014, Project “Fresh-saltwaters in
high-value coastlands: from the hydrogeophysical/geochemical characterization of the
present interactions to the modeling quantification of the expected effects of climate
changes”.
References
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cementate nella laguna di Venezia. In: La Ricerca Scientifica Per Venezia. Il Progetto Sistema
Lagunare Veneziano, Modellistica del Sistema Lagunare Studio di Impatto Ambientale.
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88-86166-82-6.
- Bonardi, M., Tosi, L., Rizzetto, F., Brancolini, G., Baradello, L. 2006. Effects of climate
changes on the late Pleistocene and Holocene sediments of the Venice Lagoon, Italy. Journal
of Coastal Research, SI 39, 279-284.
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