Idrodinamica e distribuzione di sedimenti in barre di meandro tidale

Development of meandering channels along coastal enviroments contributes to the genesis of tidal pointbar, whose morfology and depositional architecture differs from the classical model proposed for the same bodies developed in fluvial context. The present work analyses the characteristic hydrodynamic processes of a tidal meander and their consequences in terms of sediments distribution. This work focused on the comparison between a modern study case, represented by a tidal pointbar located in the northern Venice Lagune (Italy), and a fossil case, represented by Cretaceous sediments of the Tremp Formation outcropping near Tremp (Spain). The modern case was analysed in terms of morfodynamic development through the comparison of aerial photos that highlight the planimetric evolution of the pointbar in a certain interval of time. Afterwards the acquisition of flow rate mesurements (ADCP) and the high resolution facies analysis allowed to understand the architectural evolution of the pointbar. The fossil case was described through paleocurrents mesurements, facies analysis and generations of a three-dimensional model that describes geometry of the studied bodies through space. Final comparison between results of the two cases allowed to generate a new depositional model for tidal pointbars which is applicable to a wide range of modern and ancient cases.