Shallow marine sediments characterisation of the Bagnoli brownfield site, Pozzuoli Bay (Italy)

We adopted a combined geophysical-stratigraphic approach to identify grain size anomalies in sediment distribution of the Bagnoli coastal brownfield site. A large industrial plant occupied this area during most of the 20th Century. We used 18 core logs to identify macroscopic variation in sediment stratigraphy, and 72 supplemental cores to mark changes between sandy- and silt-dominated intervals. The stratigraphy evidenced the presence of anomalous lens of silt within a sandy coastal sector inside the Bagnoli industrial harbour. Cores description helped us to calibrate the interpretation of 4 subbottom profiles, that we used to obtain information on geometries of silty deposits. The spatial layout of sediments revealed that silt intervals are present in the area bounded by the old industrial wharfs. We suggest that these silty sediments are likely the result of uncontrolled discharge occurred during the last century. Once calibrated, high-resolution mono-channel seismic profiles helped us to define the shape as well as the real extent and thicknesses of silty deposits, resulted to be ca. 515.000 m(2), with an overall volume of 480.000 m(3). These results are a first attempt to define the amount of polluted sediments in the area facing the Bagnoli industrial harbour.