Seismo-stratigraphy architecture of the transgressive and highstand system tracts during the Last Glacial-Holocene and the NYT reflector in the Gulf of Gaeta (Eastern Tyrrhenian margin, Italy)

The Neapolitan Yellow Tuff caldera-forming eruption (ca 15 ky, Deino et al., 2004) is a large event that occurred at Phlegrean Fields during the Late Glacial - Holocene. The eruptive products represent a widespread isochronous marker that links the marine and terrestrial archives of the central Mediterranean area and Northern Europe. In this work, we describe the stratigraphic signature of the NYT deposits in the Late Glacial - Holocene shelf sequence of the Gulf of Gaeta (northern Campania region, southern Tyrrhenian Sea) throughout the seismo-stratigraphic interpretation of a grid of high-resolution Chirp seismic profiles. The prograding succession followed by a very thick transgressive onlapping unit and by the upper highstand unit, mainly characterized by undulations probably linked to gas-prone sediment. The NYT reflector observed is parallel and displays a high amplitude. It has been continuously detected from the shelf to the slope within the transgressive deposits. On the inner shelf, its continuity is interrupted by shallow gas pockets. The NYT depths ranges from 2 ms bsf on the slope to 38 ms bsf on the continental shelf, reaching maximum thickness at the Volturno river mouth. The NYT event appears to have played a key role in controlling the stratiigraphic architecture of the studied area during the last transgression, acting as a trigger for the formation of the aggradational sedimentary successions fed by pyroclastic and volcaniclastic deposits.