This contribution aims at emphasize the geochemical peculiarities of the soils from a coastal/deltaic sector of the Padanian plain, in relation to the associated sedimentary depositional facies. XRF and EA-IRMS analyses have been carried out in order to characterize 15 sampling sites selected along three distinct transects in the neighbors of Comacchio (Province of Ferrara). The selected sampling sites are representative of the main depositional facies of the investigated area and have been probed at the 2 depths, one representative of the plough horizon (20-30 cm depth) and one of the underlying undisturbed sedimentary layer (90-110 cm depth). A correlation matrix including all the new data highlights that siderophile heavy metals such as Cr, Ni, V, Co (ppm) are well correlated with the fine fraction and in turn with Al2O3 (wt%), showing trends analogous to those of other alluvial deposits of the Province (Bianchini et al., 2012; 2013; Di Giuseppe et al., 2014). On the other hand, other metals having chalcophile behavior display a more complex distribution, suggesting different associations. A classic example is represented by Pb, which in investigated soils plots along a distinctly higher enrichment trend with respect to other alluvial deposits of the Province. Moreover, Pb (ppm) shows a significantly higher correlation with the organic matter content (TOC, wt%) with respect to that displayed with Al2O3 (wt%), suggesting an affinity of this heavy metal for the organo-metallic compounds. In a more general framework, the enrichment in Pb is progressive from alluvial to deltaic/coastal deposits, generally from west to east of this sector of the Padanian plain, and probably associated to the presence of different depositional facies. Further investigations are going to assess the origin of this selective heavy metal accumulation, being natural or anthropogenic.
Geochemical features of distinct depositional facies in coastal/deltaic setting of the Padanian plain (Northern Italy): insights on carbon dynamics and selective metal accumulation
Natali C.;Bianchini G.;SALANI, GIAN MARCO;Tessari U.
2018
Abstract
This contribution aims at emphasize the geochemical peculiarities of the soils from a coastal/deltaic sector of the Padanian plain, in relation to the associated sedimentary depositional facies. XRF and EA-IRMS analyses have been carried out in order to characterize 15 sampling sites selected along three distinct transects in the neighbors of Comacchio (Province of Ferrara). The selected sampling sites are representative of the main depositional facies of the investigated area and have been probed at the 2 depths, one representative of the plough horizon (20-30 cm depth) and one of the underlying undisturbed sedimentary layer (90-110 cm depth). A correlation matrix including all the new data highlights that siderophile heavy metals such as Cr, Ni, V, Co (ppm) are well correlated with the fine fraction and in turn with Al2O3 (wt%), showing trends analogous to those of other alluvial deposits of the Province (Bianchini et al., 2012; 2013; Di Giuseppe et al., 2014). On the other hand, other metals having chalcophile behavior display a more complex distribution, suggesting different associations. A classic example is represented by Pb, which in investigated soils plots along a distinctly higher enrichment trend with respect to other alluvial deposits of the Province. Moreover, Pb (ppm) shows a significantly higher correlation with the organic matter content (TOC, wt%) with respect to that displayed with Al2O3 (wt%), suggesting an affinity of this heavy metal for the organo-metallic compounds. In a more general framework, the enrichment in Pb is progressive from alluvial to deltaic/coastal deposits, generally from west to east of this sector of the Padanian plain, and probably associated to the presence of different depositional facies. Further investigations are going to assess the origin of this selective heavy metal accumulation, being natural or anthropogenic.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
