The Neapolitan Yellow Tuff tephra in the stratigraphic architecture of the Gulf of Gaeta shelf, eastern Tyrrhenian margin

The Neapolitan Yellow Tuff (NYT) caldera-forming eruption (ca. 15 ka; Deino et al., 2004) is a large event occurredat Phlegraean Fields during the late Pleistocene-Holocene. The eruptive products represent a widespread isochron markerwhich links marine and terrestrial archives of the central Mediterranean area and northern Europe. In this research wedescribe the stratigraphic signature of the NYT deposits in the Late Pleistocene-Holocene shelf sequence of the Gulf ofGaeta (northern Campania region, southern Tyrrhenian sea) by using a number of gravity cores along with a grid of highand very high-resolution seismic lines.The Gulf of Gaeta represents the northern Campania continental margin that is part of a large extensional Plio-Pleistocene basin associated with normal and strike-slip faults linked to the evolution of the eastern Tyrrhenian Seamargin. Since mid-late Pleistocene, extensional tectonics took place across the continental margin and it was accompaniedby intense volcanism, from several districts of which the Phlegraean Fields activity has greatly influenced thesedimentation in this sector. The continental shelf, gently sloping seaward, is as wide as 30 km in front of the Gariglianoriver and narrows southward reaching its minimum width of ca. 10 km seaward of Cuma; the shelf break is locatedbetween 120 m and 125 m depth. The upper Pleistocene-Holocene stratigraphic architecture of the continental shelf ischaracterized by an offlap prograding succession followed by a very thick transgressive onlapping unit and by the upperhighstand unit mainly characterized in the southern sector by undulations probably linked to gas prone sediment. Theslope is characterized by a uniform profile and, in the southern sector, it is incised by several submarine gullies. Accordingto Chiocci and Casalbore (2011), the high thickness of sediment on the shelf and slope area was influenced by hyperpycnalflows, linked to the sudden and large supply of pyroclastic and volcaniclastic deposits in the Volturno river catchmentbasin.In the studied seismic sections, the NYT matches a highly continuous and parallel reflector which is interbeddedwithin the transgressive systems tract deposits. The deposit was recovered in cores raised from the slope, where it ispresent few milliseconds below the sea floor, while on the shelf where it is located at higher depths, ranging from 10 to30 ms (8 to about 25 m) below sea floor, has been mapped out through the seismic lines. The tephrostratigraphic analysisallowed to characterize the NYT in terms of lithology and chemistry and to provide new insights into the depositionalmechanisms in the marine environment. (PDF) The Neapolitan Yellow Tuff tephra in the stratigraphic architecture of the Gulf of Gaeta shelf, eastern Tyrrhenian margin. Available from: https://www.researchgate.net/publication/308296328_The_Neapolitan_Yellow_Tuff_tephra_in_the_stratigraphic_architecture_of_the_Gulf_of_Gaeta_shelf_eastern_Tyrrhenian_margin