A buried volcano in the Calabrian Arc (Italy) revealed by high‐resolution aeromagnetic data

Abstract

[1] Aeromagnetic data collected between the Aeolian volcanoes (southern Tyrrhenian Sea) and the Calabrian Arc (Italy) highlight a WNW-ESE elongated positive magnetic anomaly centered on the Capo Vaticano morphological ridge (Tyrrhenian coast of Calabria), characterized by an apical, subcircular, flat surface. Results of forward and inverse modeling of the magnetic data show a 20 km long and 3-5 km wide magnetized body that extends from sea floor to about 3 km below sea level. The magnetic properties of this body are consistent with those of the medium to highly evolved volcanic rocks of the Aeolian Arc (i.e., dacites and rhyolites). In the Calabria mainland, widespread dacitic to rhyolitic pumices with calc-alkaline affinity of Pleistocene age (1-0.7 Ma) are exposed. The tephra falls are related to explosive activity and show a decreasing thickness from the Capo Vaticano area southeastward. The presence of lithics indicates a provenance from a source located not far from Capo Vaticano. The combined interpretation of the magnetic and available geological data reveal that (1) the Capo Vaticano WNW-ESE elongated positive magnetic anomaly is due to the occurrence of a WNW-ESE elongated sill; (2) such a sill represents the remnant of the plumbing system of a Pleistocene volcano that erupted explosively producing the pumice tephra exposed in Calabria; and (3) the volcanism is consistent with the Aeolian products, in terms of age, magnetic signature, and geochemical affinity of the erupted products,. The results indicate that such volcanism developed along seismically active faults transversal to the general trend of the Aeolian Arc and Calabria block, in an area where uplift is maximized (∼4 mm/yr). Such uplift could also be responsible for fragmentation of the upper crust and formation of transversal faults along which seismic activity and volcanism occur.

High-resolution aeromagnetic survey of Calabria (Southern Italy)

“…The overall low intensity and the wavelength of the observed magnetic anomalies are consistent with the weak magnetization of exposed crystalline and sedimentary rocks (Cifelli et al, 2007;De Ritis et al, 2010;Macrì et al, 2014;Mattei et al, 1999Mattei et al, , 2002. In turn, the weak magnetic anomaly values in the investigated area are in agreement with results of previous magnetic surveys of the same region (Agip SpA Italia, 1981;Caratori Tontini et al, 2004;Chiappini et al, 2000).…”

“…Both scattered magnetic measurements of the Hercynian basement (De Ritis et al, 2010) and systematic magnetic analyses of the Miocene-Pleistocene marine clays (Cifelli et al, 2007;Mattei et al, 1999Mattei et al, , 2002Macrì, Speranza, & Capraro, 2014) revealed very low magnetic susceptibility values in the order of 1-2 × 10 −4 SI.…”

Geophysical investigation of Pleistocene volcanism and tectonics offshore Capo Vaticano (Calabria, southeastern Tyrrhenian Sea)

“…Previously published aeromagnetic data (De Ritis et al, 2010b) have been reprocessed in order to obtain a better extraction of the CV anomaly out off the regional magnetic field. Indeed, the anomaly and its -Reduced to The Pole‖ (hereafter RTP) transformation (Baranov and Naudy 1964, e.g., RTP-CV-anomaly) display an extension forming a tail of several kilometres to the east and northeast (Figs.…”

Structure and evolution of Cenozoic arc magmatism on the Antarctic Peninsula: a high resolution aeromagnetic perspective

“…Here we use recently acquired high resolution aeromagnetic data over Adelaide Island, on the western margin of the AP (Figs 1 and 2), to investigate the processes occurring along the arc/forearc boundary. High resolution aeromagnetic data has elsewhere been used to reveal tectonic structures in forearc regions (Ponce et al 2003;Saltus et al 2005), the geometry of arc magmatic intrusions (De Ritis et al 2010), and tectonic and magmatic patterns in rift systems formed along the reactivated margins of older magmatic arc terranes (Ferraccioli et al 2005). We apply digital enhancement, 2-D modelling and 3-D inversion to the new magnetic data in order to reveal the structure of the AP arc/forearc boundary.…”