Multi-proxy analysis in defining sedimentary processes in very recent prodelta deposits: the Northern Phlaegrean offshore example (Eastern Tyrrhenian margin)

A multi-proxy analysis of Volturno River prodelta deposits in the outer shelf of Northern Phlegrean margin (Eastern Tyrrhenian Sea), has been carried out in order to reconstruct the sedimentary processes acting during recent times. The Holocene upper unit was characterized through Subbottom Chirp profiles coupled with sedimentological and petrophysical data. The chronostratigraphic framework was achieved by means of colorimetric parameter a* correlations with nearby dated marine sediment. A time interpretation of about 2300 years BP is estimated for the sedimentary record collected in the cores. Seismic profiles interpretation shows late Holocene high stand shelf deposits, affected by undulation phenomena. The undisturbed sedimentation and the preservation of an internal geometry at decimetre scale, as detected by the sedimentological and petrophysical analysis, indicates a slow sliding without sediment reworking for this sedimentological body. So far a possible recent (minor than 2300 years B.P.) shear ominated limited downward displacement is inferred, characterized by small-offset faults, related to high water content, fluid escape features and triggered by the occurrence of seismic activity. Based on the depth-age conversion of the detected lithological features, a regular climatically driven change in the sediment supply of the prodelta depositional environment is suggested. The detection of spectrophotometry correlations of Holocene shelf margin sediments, several km apart, goes beyond the previous work, and confirms even for continental shelf area, the potential value of spectrophotometer data in high resolution stratigraphic correlations.