The Neapolitan Yellow Tuff record in the Gaeta Gulf (Eastern Tyrrhenian margin, Southern Italy)

Abstract

Abstract. The Neapolitan Yellow Tuff caldera-forming eruption (ca. 15 kyr) is a large event that occurred at Phlegrean Fields during the Late Glacial–Holocene time span. The eruptive products represent a widespread isochronous marker that links the marine and terrestrial stratigraphic record of the central Mediterranean and Northern Europe sequences. In this research, 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 and very high-resolution Chirp seismic profiles. The seismo-stratigraphic data allowed to individuate in the Upper Pleistocene–Holocene stratigraphic architecture a continental shelf characterized by an offlap prograding succession followed by a very thick transgressive onlapping unit, and by an upper highstand unit mainly characterized by undulations probably linked to gas-prone sediment. The NYT reflector observed was parallel and with a high amplitude. It was continuously detected from the shelf to the slope within transgressive deposits. On the inner shelf, its continuity was interrupted by shallow gas pockets. The NYT depths ranges from 2 m b.s.f. on the slope to 38 m b.s.f. on the continental shelf. The NYT event appeared to have played a key role in controlling the stratigraphic 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.