Benthic fluxes and early diagenesis processes in Adriatic Sea.

During the last decades various researches in the Adriatic and Ionian Sea allowed the individuation of different area characterized by various early diagenesis environments that generate dissolved fluxes at the sediment-water interface with different intensity. North of the Po River a thin and discontinuous band of terrigenous fine carbonate sediment and with different reactivity of organic matter produces benthic flues extremely variable in functions of the fresh organic matter entered by the main rivers In front of the Po River a limited area, with high sedimentation rate and high continental and autochthonous organic matter inputs, generates high nutrient benthic fluxes. In the western Adriatic sediments are characterised by progressive southward decrease of sedimentation rate and reactive organic matter that generate decreasing benthic fluxes. The central Adriatic Sea bottom sediment area is characterized by prevalently carbonate sediments and low fluxes of nutrients due to little organic and inorganic inputs and to precipitation of authigenic mineral. In the Meso-Adriatic and South Adriatic Depression low sedimentation rates and strongly reworked organic and inorganic matter produce very low benthic nutrient fluxes. In Ionian Sea slope sediments are carachterized by very lo particulate imputs and by negative fluxes of DIC acting in this way as CO2 traps while basin sedimts show higher benthic fluxes due to increses of organic matter inputs.