New seismo-stratigraphic and marine magnetic data of the Gulf of Pozzuoli (Naples Bay, Tyrrhenian Sea, Italy): inference

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ORIGINAL RESEARCH PAPER

New seismo-stratigraphic and marine magnetic data of the Gulf of Pozzuoli (Naples Bay, Tyrrhenian Sea, Italy): inferences for the tectonic and magmatic events of the Phlegrean Fields volcanic complex (Campania) Gemma Aiello • Ennio Marsella • Vincenzo Di Fiore

Received: 13 December 2011 / Accepted: 4 April 2012 / Published online: 26 April 2012 Ó Springer Science+Business Media B.V. 2012

Abstract A detailed reconstruction of the stratigraphic and tectonic setting of the Gulf of Pozzuoli (Naples Bay) is provided on the basis of newly acquired single channel seismic profiles coupled with already recorded marine magnetics gathering the volcanic nature of some seismic units. Inferences for the tectonic and magmatic setting of the Phlegrean Fields volcanic complex, a volcanic district surrounding the western part of the Gulf of Naples, where volcanism has been active since at least 50 ka, are also discussed. The Gulf of Pozzuoli represents the submerged border of the Phlegrean caldera, resulting from the volcano-tectonic collapse induced from the pyroclastic flow deposits of the Campanian Ignimbrite (35 ka). Several morpho-depositional units have been identified, i.e., the inner continental shelf, the central basin, the submerged volcanic banks and the outer continental shelf. The stratigraphic relationships between the Quaternary volcanic units related to the offshore caldera border and the overlying deposits of the Late Quaternary depositional sequence in the Gulf of Pozzuoli have been highlighted. Fourteen main seismic units, both volcanic and sedimentary, tectonically controlled due to contemporaneous folding and normal faulting have been revealed by geological interpretation. Volcanic dykes, characterized by acoustically transparent sub-vertical bodies, locally bounded by normal faults, testify to the magma uprising in correspondence with extensional structures. A large field of tuff cones interlayered with marine deposits off the island of Nisida, on the western rim of the gulf, is related to the

G. Aiello (&)  E. Marsella  V. D. Fiore Institute of Marine, Environment and Coastal Area (IAMC), National Research Council (CNR), Calata Porta di Massa, Porto di Napoli, 80133 Naples, Italy e-mail: [email protected]

emplacement of the Neapolitan Yellow Tuff deposits. A thick volcanic unit, exposed over a large area off the Capo Miseno volcanic edifice is connected with the Bacoli-Isola Pennata-Capo Miseno yellow tuffs, cropping out in the northern Phlegrean Fields. Keywords Gulf of Pozzuoli  Seismic stratigraphy  Marine magnetics  Phlegrean fields  Volcanology

Introduction The aim of this paper is to provide new seismo-stratigraphic evidence from the Gulf of Pozzuoli, Italy, on the basis of the geological interpretation of recently collected Sparker profiles in order to deliver an up-to-date geological setting of the area during the Late Quaternary through seismo-stratigraphic concepts. In this way, the geological knowledge on the active volcanic area of the Phlegrean Fields (Napl