Deep and shallow gas occurrence in the NW Sicilian Channel and related features

• Published in: Marine and petroleum geology Vol. 139; p. 105575
• Main Authors: Ferrante, Giulia Matilde, Accaino, Flavio, Civile, Dario, Lodolo, Emanuele, Volpi, Valentina, Romeo, Roberto, Accettella, Daniela
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2022
• Subjects: AVO analysis; High-resolution and multi-channel seismic profiles; Mud-volcanoes; Phase inversion; Pockmarks; Sicilian Channel; Thermogenic gas; Tomographic inversion; Phase inversion; High-resolution and multi-channel seismic profiles; AVO analysis; Sicilian Channel; Thermogenic gas; Pockmarks; Mud-volcanoes; Tomographic inversion
• ISSN: 0264-8172; 1873-4073
• DOI: 10.1016/j.marpetgeo.2022.105575

In this paper we present a combined analysis of recent swath bathymetric data, very high-resolution seismic and multi-channel seismic profiles, integrated with a vintage crustal seismic profile, acquired in the NW Sicilian Channel (Central Mediterranean Sea). These data have been analyzed with the main aim of studying the gas presence and related features in both the subsurface and at the seafloor, through the recognition of amplitude and velocity anomalies in the entire Miocene-Pleistocene sedimentary succession. Our results shed light on the possible gas origin and migration mechanisms. In particular, we support the hypothesis of a gas derivation by thermal cracking of organic matter and suggest the shaly/marly intercalations hosted in the Meso-Cenozoic carbonate succession as a possible source rock. Deep lithospheric faults systems and associated fractures provide preferential paths for gas migration and accumulation in the Miocene-Quaternary sandy and carbonate layers. Gas is then able to locally reach the seafloor originating positive (mud volcanoes) and negative (pockmarks) morphologies. •In the NW Sicilian Channel gas-related features are found in the whole Miocene-Pleistocene succession.•Techniques such as tomographic inversion and AVO analysis are used to recognize gas accumulation at depth.•The sub-bottom seismic profiles and the bathymetric data show the gas seeping history towards the seabed.•Gas may have a thermogenic origin, being generated by the shaly/marly intercalations of the Meso-Cenozoic carbonates.•Gas upward migration could exploit regional NNE-trending lithospheric faults systems and related fractures.