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.
Sedimentological, geochemical and biogeochemical facies of Central and Southern Adriatic Sea.
De Marco R;Spagnoli F
2019
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
