Fluid escape structures in the Graham Bank region (Sicily Channel, Central Mediterranean) revealing volcanic and neotectonic activity

In the Sicily Channel, (Central Mediterranean), two geodynamic processes overlap each other, the Maghrebides- Apennines accretionary prism and the Sicily Channel rift. Moreover, the northwestern sector (Banks sector) is characterised by an irregular seafloor morphology linked to the recent volcanic and tectonic activity.In order to discriminate the role exerted by both the processes in the morphostructural setting of the area we used a dataset of both high and very high resolution single-channel and multi-channel profiles, acquired in the frame of the RITMARE project respectively with CHIRP and sparker, and airgun sources, and high resolution (5 m cell) morpho-bathymetric data. The data all…

The geographic information in the assessment of geohazard in the marine environment

Slope instability and erosion, mass transport, volcanic and tectonic activity, fast sediment accumulation fluid escape are the main processes responsible for the geohazard in marine environment. A major knowledge about the geological setting of the offshore areas and related processes can be crucial to assess and manage the potential geological risks. High resolution morphobathymetric surveys, yielded in the frame of the MaGIC project (Marine Geohazards along the Italian Coasts), integrated with previously acquired data, single-channel seismic reflection profiles, backscatter data and sediments sampling, allow to define the geomorphological, stratigraphic and structural features in the offs…

Towards a new marine structural model of Italy

The exploitation of economic resources in marine environment and the assessment of natural hazards press a greater knowledge of the sea floor geology. Since the Structural Model of Italy was published in the 1991 by the CNR, new data have been collected concerning the marine geology of the sea floor surrounding Italy, also by means of up to date technologies (digital seismics, SBP Chirp, Multibeam). Data collected during the last decades in the frame of research programs as CROP MARE, CARG, morpho-bathymetric survey of the Tyrrhenian Sea, MAGIC, allow investigating the submerged geological structures with different temporal and spatial resolution. As consequence, at present marine geologist…

Paleoenvironmental and tectonic evolution of the Liassic carbonate platform succession of Mt. Maranfusa (central western Sicily)

The upper part of the Liassic carbonate platform succession (Inici Fm., Hettangian-Sinemurian), outcropping at Mt. Maranfusa (central western Sicily) consists of a sequence of peritidal limestones, overlain by Jurassic to Cenozoic pelagic limestones and their siliciclastic Tertiary covers. The good exposure of this succession, pertaining to the trapanese domain, in the area between Palermo and Sciacca mountains, allowed to study in detail the facies sequences and structural features of the carbonate platform and of the sedimentary dikes, in order to improve knowledge on its paleoenvironmental and tectonic evolution. The Inici Fm. is constituted by subtidal cyclic sequences of wackestone\pac…

I BACINI SIN-OROGENICI AL TETTO DELLA CATENA SICILIANA EVOLUZIONE TRA IL SERRAVALLIANO SUPERIORE E IL MESSINIANO INFERIORE

Questa ricerca riguarda l’analisi di bacini sintettonici neogenici che si sono sviluppati in varie posizioni rispetto all'orogene siciliano-maghrebide. Lo studio dei bacini in ambiente cinematico convergente e dei depositi che ne costituiscono il riempimento sedimentario, rappresenta uno degli strumenti fondamentali per la comprensione delle modalità con cui avviene la progressiva strutturazione di una zona di catena. In questo lavoro sono stati analizzati i bacini con riempimento di età compresa tra il Serravalliano superiore e il Messiniano inferiore, che si trovano sul fronte e sul dorso della catena siciliana (Thrust Top Basin, Piggy Back Basin) mettendoli in relazione dal punto di vist…

Hydrothermal fluid venting in the offshore sector of Campi Flegrei caldera: A geochemical, geophysical, and volcanological study

The ongoing unrest at the Campi Flegrei caldera (CFc) in southern Italy is prompting exploration of its poorly studied offshore sector. We report on a multidisciplinary investigation of the Secca delle Fumose (SdF), a submarine relief known since antiquity as the largest degassing structure of the offshore sector of CFc. We combined high-resolution morpho-bathymetric and seismo-stratigraphic data with onshore geological information to propose that the present-day SdF morphology and structure developed during the initial stages of the last CFc eruption at Monte Nuovo in AD 1538. We suggest that the SdF relief stands on the eastern uplifted border of a N-S-trending graben-like structure forme…

Subaerial exposure and drowning processes in a carbonate platform during the Mesozoic Tethyan rifting: The case of the Jurassic succession of Western Sicily (central Mediterranean)

Abstract The Liassic carbonate platform succession outcropping at Monte Maranfusa (central Western Sicily) consists of a shallowing-upward sequence of peritidal carbonates, with Jurassic to Paleogene pelagic limestone and siliciclastic Tertiary covers above. The cyclic sequences of subtidal wackestones/packstones, intertidal microcrystalline carbonates with bird's-eye pores, and supratidal bioclastic grainstones are interbedded with dark layers of the following composition: 1) dark-gray, compact, and well-cemented limestone with blackish clasts, interpreted as calcretes (a type of carbonate soil) and 2) reddish calcite laminae, deformed by elongated cavities, filled with vadose silt, interp…

Fluid escape structures in the north Sicily continental margin

Abstract High resolution and multichannel seismic profiles coupled with multibeam echosounder (seafloor relief) data, acquired along the northern Sicily continental margin (southern Tyrrhenian Sea), document the occurrence of mound and pockmark features, revealing fluid escape processes. Along this margin, morphology of the high-gradient continental slope is irregular due to the presence of structural highs, slope failures and canyons, and is interrupted by flat areas at a mean depth of 1500 m. Seismostratigraphic analysis tools and methods were used to identify fluid escape structures and to work out a classification on the basis of their morpho-acoustic characteristics. The detailed 3D ba…

Tectonics vs. sedimentation during the Sicilian orogenesis. The case history of upper Miocene terrigenuous basins in the central-eastern Sicily

Progetto MAGIC: “L’informazione territoriale nella valutazione del rischio geologico in ambiente marino”. . In: Workshop GIS Day: "GIStales: di dati, persone e strumenti”.

MaGIC è un progetto quinquennale (2007-2012) finanziato dal Dipartimento Nazionale della Protezione Civile per l'acquisizione di dati morfobatimetrici ad alta risoluzione. Lo scopo principale del progetto è quello di definire e rappresentare i principali elementi morfologici dei fondali marini, in particolar modo quelli derivanti da dinamiche morfo-sedimentarie che implicano mobilità e/o instabilità dei sedimenti e conseguenti situazioni di pericolosità per le infrastrutture e le aree costiere urbanizzate. I rilievi morfobatimetrici vengono realizzati con un sistema ecoscandaglio radiale multifascio (Multibeam echosounder systems) calibrato ad hoc nell’area di lavoro e corretto in velocità …

Upper Miocene siliciclastic depositional systems in the central-eastern Sicily basins