The southwestern Sicily represents a key sector for studying the Late Pliocene-Pleistocene stratigraphic evolution of the Sicilian foreland-basin system. The data collected during the realization of the sheets n.628 “Sciacca” and n.618 “Castelvetrano” (CARG project) revealed important sedimentological, stratigraphic, and tectonic features, enabling the accurate geological reconstruction of two sedimentary basins (Menfi and Ribera basin) set on different sectors of the Sicilian Fold and Thrust Belt (FTB). Both are located in the outer sector of the FTB, but the Menfi succession accumulated on a deformed carbonate substrate constituted by the Saccense Domain, while the Ribera succession covers the deformed substrate constituted by the Gela Thrust wedge. One of the most innovative aspects of this study is represented by the 3D geological model reconstruction. By integrating data from geological mapping, seismic reflection profiles, well logs, geophysical surveys, geological cross-sections a detailed three-dimensional model was produced, greatly improving the understanding of the sedimentary and structural dynamics of the southwestern Sicily. In the Menfi basin, the Late Pliocene-Pleistocene succession includes the marnoso-arenacea del Belice formation (Piacenzian-Gelasian), constituted by hemipelagic clayey marls, turbiditic sandy silts, and breccias, transitioning to resedimented arenites and calcarenites. This unit passes upward to the Agrigento formation (Calabrian), consisting of hemipelagic clays and marls with intercalated sands and bio-calcarenites. In the south-eastern sector, the Ribera basin succession includes the Monte Narbone formation (Middle Piacenzian-Early Calabrian), composed of marls and silty clays alternating with sapropelitic layers. Upward, this latter unit is overlain by the Agrigento formation, here featured by thick bio-calcarenites, with cross-lamination and prograding geometries, alternated with sandy marls and clays. The 3D geo-structural model of the study area well shows as the Monte San Calogero, a ramp anticline with double vergence and left-lateral transpressive kinematics, acts as a structural high separating these two basins. Data revealed that the Menfi sedimentary basin thickens from west to east, reaching about 1250 meters, while the Ribera basin reaches the thickness of 2200 meters, in the offshore sector. The realization of 3D geological model and the creation of thickness maps for the Plio-Pleistocene sedimentary sequence provided crucial insights into sedimentary and tectonic processes, significantly enhancing the understanding of the Sicilian FTB evolution.
High-resolution 3D model of Plio-Pleistocene stratigraphy succesion in Southwestern Sicily foreland-basin system
Rizzo G. F.
;
2024-01-01
Abstract
The southwestern Sicily represents a key sector for studying the Late Pliocene-Pleistocene stratigraphic evolution of the Sicilian foreland-basin system. The data collected during the realization of the sheets n.628 “Sciacca” and n.618 “Castelvetrano” (CARG project) revealed important sedimentological, stratigraphic, and tectonic features, enabling the accurate geological reconstruction of two sedimentary basins (Menfi and Ribera basin) set on different sectors of the Sicilian Fold and Thrust Belt (FTB). Both are located in the outer sector of the FTB, but the Menfi succession accumulated on a deformed carbonate substrate constituted by the Saccense Domain, while the Ribera succession covers the deformed substrate constituted by the Gela Thrust wedge. One of the most innovative aspects of this study is represented by the 3D geological model reconstruction. By integrating data from geological mapping, seismic reflection profiles, well logs, geophysical surveys, geological cross-sections a detailed three-dimensional model was produced, greatly improving the understanding of the sedimentary and structural dynamics of the southwestern Sicily. In the Menfi basin, the Late Pliocene-Pleistocene succession includes the marnoso-arenacea del Belice formation (Piacenzian-Gelasian), constituted by hemipelagic clayey marls, turbiditic sandy silts, and breccias, transitioning to resedimented arenites and calcarenites. This unit passes upward to the Agrigento formation (Calabrian), consisting of hemipelagic clays and marls with intercalated sands and bio-calcarenites. In the south-eastern sector, the Ribera basin succession includes the Monte Narbone formation (Middle Piacenzian-Early Calabrian), composed of marls and silty clays alternating with sapropelitic layers. Upward, this latter unit is overlain by the Agrigento formation, here featured by thick bio-calcarenites, with cross-lamination and prograding geometries, alternated with sandy marls and clays. The 3D geo-structural model of the study area well shows as the Monte San Calogero, a ramp anticline with double vergence and left-lateral transpressive kinematics, acts as a structural high separating these two basins. Data revealed that the Menfi sedimentary basin thickens from west to east, reaching about 1250 meters, while the Ribera basin reaches the thickness of 2200 meters, in the offshore sector. The realization of 3D geological model and the creation of thickness maps for the Plio-Pleistocene sedimentary sequence provided crucial insights into sedimentary and tectonic processes, significantly enhancing the understanding of the Sicilian FTB evolution.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
