Buried volcanic structures in the Gulf of Naples (Southern Tyrrhenian Sea, Italy) resulting from high resolution magnetic survey and seismic profiling

B D'argenio B D'Argenio,N Pelosi N Pelosi,G Aiello G Aiello,A Siniscalchi A Siniscalchi,E Marsella E Marsella,A Angelino A Angelino,S Ruggieri S Ruggieri

doi:10.4401/ag-3241

Abstract

In this paper we present a correlation between volcanic structures and magnetic anomalies in the Gulf of Naples (Southern Tyrrhenian Sea) based on high resolution magnetic profiling. A densely spaced grid of magnetic profiles coupled with multichannel seismics (seismic source Watergun 15 cubic inch) was recorded in the Gulf of Naples, representing an active volcanic area during the Late Quaternary (volcanic centers of Somma-Vesuvius, Phlegraean Fields and Ischia and Procida islands). The dataset was collected during the oceanographic cruise GMS00-05 which took place during October-November 2000 in the South Tyrrhenian Sea onboard of the R/V Urania (National Research Council, Italy). Shallow volcanic structures in the subsurface of the gulf were recognized by seismo-stratigraphic analysis of high resolution profiles; the volcanic nature of some of these structures was inferred identifying the magnetic anomalies on a high resolution magnetic anomaly map of the gulf. Even if qualitative, the correlations between seismic and magnetic profiles allow us to better assess the geological structure of the Gulf of Naples.

Highlights

Aim of this paper is to present an integrated study of magnetic and seismic profiles recorded in the Gulf of Naples (Southern Tyrrhenian Sea, Italy) finalized to reconstruct the Late Quaternary geological framework of the gulf
Significant interest has been focused on the interpretation of high-resolution multichannel seismic profiles coupled to maps of total magnetic field in order to contribute to the understanding of volcanic structures in the Gulf of Naples and the reconstruction of the Late Qua-Gemma Aiello, Antimo Angelino, Bruno D’Argenio, Ennio Marsella, Nicola Pelosi, Stefano Ruggieri and Agata Siniscalchi ternary geological setting of the investigated area
This method, even if qualitative in the present discussion, improved the geological knowledge in an active volcanic area as the Gulf of Naples, since it disclosed and located several main volcanic bodies based on seismic interpretation, well constrained by the occurrence of significant magnetic anomalies

Summary

Introduction

Aim of this paper is to present an integrated study of magnetic and seismic profiles recorded in the Gulf of Naples (Southern Tyrrhenian Sea, Italy) finalized to reconstruct the Late Quaternary geological framework of the gulf. The Serapis active seismic survey recently covered the entire Bay of Naples, allowing the computation of three-dimensional P-wave velocity distribution of the gulf, including a small-scale high-resolution model of the Phlegraean Fields caldera (Judenherc and Zollo, 2004). 2. Qualitative geologic interpretation of this map disclosed the occurrence of complex magnetic anomaly fields in the gulf, associated with shallow volcanic structures, as evidenced by the interpretation of seismic reflection profiles and/or to volcanic morphological and structural highs, identified on high resolution Multibeam bathymetry of the gulf (Aiello et al, 2001a; Marsella et al, 2002; Siniscalchi et al, 2002). There is a good regional correlation between structural geology of shallow structures and magnetic anomalies

Geologic setting

Magnetic data

Seismic data

Eastern Gulf of Naples

Western Gulf of Naples

Discussion and conclusions