Sedimentological, geochemical and biogeochemical facies of Central and Southern Adriatic Sea.
Droghini E.; Dinelli E.; Tramontana M.; De Marco R.; Baldelli G.; Pappafico G.; Spagnoli F.;
The Adriatic Sea is a basin oriented in the NW-SE direction, which represents the result of filling the
Apennine and Dinaric-Hellenic chain foredeep. The present surface sediment distribution is controlled by basin
evolution, different sediment source areas and processes. The aims of this work were to identify sedimentary
facies based on grain-size, geochemical and biogeochemical features and to describe their spatial distribution,
to recognize regional patterns of sediment dispersal, geochemical signals for provenance and eventual local
features.
Grain-size, geochemical (major and trace elements) and biogeochemical (organic carbon) analysis
(Droghini, 2017) carried out on 107 samples, collected by box-corer during the PERTRE cruise (Spagnoli,
2016). These data were elaborated with a Q-mode factor analysis to identify the sedimentary facies (Spagnoli
et al., 2014). In particular the statistical processing of sediment properties highlighted 5 factors, which allowed
characterizing different facies and to evaluate their provenance and surface distribution. In particular were
identified: 1) Clayey facies, made up of clayey and clayey-silty sediments, originated from the contribution of
the Po River and the Apennine rivers, and that are redistributed by the Adriatic circulation in a SE direction; 2)
sandy facies, made up of sandy-silty sediments with silicate minerals and enriched in Magnesium; this facies
is more abundant along the Italian coasts; 3) coarse carbonatic facies, made up of sandy-gravel sediments; this
facies is more abundant in the outer areas of the Adriatic Basin, coinciding with the depositional areas of the
relict sands; 4) silty facies with heavy minerals, characterized by silty sediments enriched in heavy minerals
resulting from the action of waves and coastal currents; 5) sediment provenance, useful to identify the origin of
sediments. This component shows high values in different areas mainly located offshore of northern Gargano
Promontory and is due to sediment features mainly controlled by geochemistry rather than grain-size.
The characterization and distribution of the above described facies allowed understanding in more detail the
present hydrodynamic, sedimentological, geochemical and biogeochemical processes occurring in the Central
and Southern Adriatic Sea, and to identify the main sediment source areas.
2019 - Abstract in atti di convegno
La geologia marina in Italia, Terzo Convegno dei geologi marini italiani - Roma, 21-22 febbraio 2019, Roma, 21/02/2019, 22/02/2019
Keywords: Adriatic Sea