1. Tectonic-Sedimentary evolution of the Tuscan shelf: seismic-stratigraphic analysis of Neogenic succession in the norther Tyrrhenian sea (Elba Island - Argentario)
- Author
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Cavirani, Ilario, Musumeci, Giovanni, Buttinelli, Mauro, and Mazzarini, Francesco
- Subjects
Northern Tyrrhenian Sea ,evolutionary model ,Tuscan shelf ,Neogenic basins ,extensional tectonics - Abstract
This thesis focuses on the interpretation of a dataset of reflection seismic profiles acquired during the 1970s in the area of the Northern Tyrrhenian Sea between the Elba Island and the Argentario promontory, by means of the MidlandValley Move and KogeoSeismic Toolkit software. This allowed to carry out two-dimensional and three-dimensional analyses of the profiles and to build 3D models of the main structures characterizing the Tuscany platform. The use of stratigraphic data from the Martina-1 and Mimosa-1 exploration wells and from the ground geology of the island of Pianosa, together with the analysis of the seismic profiles and the data deriving from the bibliographic study, enabled the reconstruction of the seismic stratigraphic succession of the area. We identified and described eight seismostratigraphic units separated by eight unconformities. Among these seismostratigraphic units, there are six post-orogenic units (Pa, Pb, Pc, Pd, Pe and Pq) representing the Neogenic succession covering the Tuscan platform, and two deeper Sub 1 and Sub 2 units representing the pre-Neogenic foundation. The analysis of the seismic profiles allowed to define the structural architecture of the Tuscany platform. The main structures of this platform are the Neogenic basins of Montecristo, Punta Ala and Uccellina, which extend along N-S and NE-SW trajectories and within which the post-orogenic seismostratigraphic units are deposited. The main contribution of this thesis work is the reconstruction of the tectonic-sedimentary evolution of the Tuscan platform, with specific reference to the basins and their relationship with previous compressive structures consisting of East thrust verges linked to the chain structuring processes in the Tyrrhenian sector. Several normal fault systems were identified and described, which consist of medium-high angle faults with predominantly NS and NE-SW direction and immersion both towards West and East, whose activation and deactivation drove the development of Neogenic basins. No normal listric and low angle fault systems were observed. Based on the results obtained from the detailed analysis of the seismic profiles and from their 3D modeling, an evolutionary model of the Tuscany platform was proposed. The formation of the Neogenic basins, resulting from of the extensional tectonic processes within the entire Tuscan shelf, began in the upper Burdigalian. The basins initially constitute intermontane basins developing along the flanks of the antiforms that derive from previous compressive tectonics. The initial position of the basins, over the forelimb or the backlimb of the thrust antiforms, influences the (respectively) asymmetrical or symmetrical shape along which the basins develop. Starting from the Messinian, there is a general vertical collapse of the platform, which leads to the deepening of the basins driven by the normal high-angle border faults. This process continues up to the lower Pliocene, when the deactivation of all normal faults is recorded, and conditions of widespread subsidence are witnessed throughout the platform together with the deposition of the two more superficial post-orogenic seismostratigraphic units (Pe, Pq). This thesis thus (i) reviews the tectonic evolution of the northern Tyrrhenian Sea and the previous extensional models proposed, (ii) questions both the mechanisms so far presented as responsible for the extensional processes, as well as the structures associated with them, and (iii) establishes a new starting point for the development of future work aimed at strengthening and completing the model. This thesis focuses on the interpretation of a dataset of reflection seismic profiles acquired during the 1970s in the area of the Northern Tyrrhenian Sea between the Elba Island and the Argentario promontory, by means of the MidlandValley Move and KogeoSeismic Toolkit software. This allowed to carry out two-dimensional and three-dimensional analyses of the profiles and to build 3D models of the main structures characterizing the Tuscany platform. The use of stratigraphic data from the Martina-1 and Mimosa-1 exploration wells and from the ground geology of the island of Pianosa, together with the analysis of the seismic profiles and the data deriving from the bibliographic study, enabled the reconstruction of the seismic stratigraphic succession of the area. We identified and described eight seismostratigraphic units separated by eight unconformities. Among these seismostratigraphic units, there are six post-orogenic units (Pa, Pb, Pc, Pd, Pe and Pq) representing the Neogenic succession covering the Tuscan platform, and two deeper Sub 1 and Sub 2 units representing the pre-Neogenic foundation. The analysis of the seismic profiles allowed to define the structural architecture of the Tuscany platform. The main structures of this platform are the Neogenic basins of Montecristo, Punta Ala and Uccellina, which extend along N-S and NE-SW trajectories and within which the post-orogenic seismostratigraphic units are deposited. The main contribution of this thesis work is the reconstruction of the tectonic-sedimentary evolution of the Tuscan platform, with specific reference to the basins and their relationship with previous compressive structures consisting of East thrust verges linked to the chain structuring processes in the Tyrrhenian sector. Several normal fault systems were identified and described, which consist of medium-high angle faults with predominantly NS and NE-SW direction and immersion both towards West and East, whose activation and deactivation drove the development of Neogenic basins. No normal listric and low angle fault systems were observed. Based on the results obtained from the detailed analysis of the seismic profiles and from their 3D modeling, an evolutionary model of the Tuscany platform was proposed. The formation of the Neogenic basins, resulting from of the extensional tectonic processes within the entire Tuscan shelf, began in the upper Burdigalian. The basins initially constitute intermontane basins developing along the flanks of the antiforms that derive from previous compressive tectonics. The initial position of the basins, over the forelimb or the backlimb of the thrust antiforms, influences the (respectively) asymmetrical or symmetrical shape along which the basins develop. Starting from the Messinian, there is a general vertical collapse of the platform, which leads to the deepening of the basins driven by the normal high-angle border faults. This process continues up to the lower Pliocene, when the deactivation of all normal faults is recorded, and conditions of widespread subsidence are witnessed throughout the platform together with the deposition of the two more superficial post-orogenic seismostratigraphic units (Pe, Pq). This thesis thus (i) reviews the tectonic evolution of the northern Tyrrhenian Sea and the previous extensional models proposed, (ii) questions both the mechanisms so far presented as responsible for the extensional processes, as well as the structures associated with them, and (iii) establishes a new starting point for the development of future work aimed at strengthening and completing the model. This thesis focuses on the interpretation of a dataset of reflection seismic profiles acquired during the 1970s in the area of the Northern Tyrrhenian Sea between the Elba Island and the Argentario promontory, by means of the MidlandValley Move and KogeoSeismic Toolkit software. This allowed to carry out two-dimensional and three-dimensional analyses of the profiles and to build 3D models of the main structures characterizing the Tuscany platform. The use of stratigraphic data from the Martina-1 and Mimosa-1 exploration wells and from the ground geology of the island of Pianosa, together with the analysis of the seismic profiles and the data deriving from the bibliographic study, enabled the reconstruction of the seismic stratigraphic succession of the area. We identified and described eight seismostratigraphic units separated by eight unconformities. Among these seismostratigraphic units, there are six post-orogenic units (Pa, Pb, Pc, Pd, Pe and Pq) representing the Neogenic succession covering the Tuscan platform, and two deeper Sub 1 and Sub 2 units representing the pre-Neogenic foundation. The analysis of the seismic profiles allowed to define the structural architecture of the Tuscany platform. The main structures of this platform are the Neogenic basins of Montecristo, Punta Ala and Uccellina, which extend along N-S and NE-SW trajectories and within which the post-orogenic seismostratigraphic units are deposited. The main contribution of this thesis work is the reconstruction of the tectonic-sedimentary evolution of the Tuscan platform, with specific reference to the basins and their relationship with previous compressive structures consisting of East thrust verges linked to the chain structuring processes in the Tyrrhenian sector. Several normal fault systems were identified and described, which consist of medium-high angle faults with predominantly NS and NE-SW direction and immersion both towards West and East, whose activation and deactivation drove the development of Neogenic basins. No normal listric and low angle fault systems were observed. Based on the results obtained from the detailed analysis of the seismic profiles and from their 3D modeling, an evolutionary model of the Tuscany platform was proposed. The formation of the Neogenic basins, resulting from of the extensional tectonic processes within the entire Tuscan shelf, began in the upper Burdigalian. The basins initially constitute intermontane basins developing along the flanks of the antiforms that derive from previous compressive tectonics. The initial position of the basins, over the forelimb or the backlimb of the thrust antiforms, influences the (respectively) asymmetrical or symmetrical shape along which the basins develop. Starting from the Messinian, there is a general vertical collapse of the platform, which leads to the deepening of the basins driven by the normal high-angle border faults. This process continues up to the lower Pliocene, when the deactivation of all normal faults is recorded, and conditions of widespread subsidence are witnessed throughout the platform together with the deposition of the two more superficial post-orogenic seismostratigraphic units (Pe, Pq). This thesis thus (i) reviews the tectonic evolution of the northern Tyrrhenian Sea and the previous extensional models proposed, (ii) questions both the mechanisms so far presented as responsible for the extensional processes, as well as the structures associated with them, and (iii) establishes a new starting point for the development of future work aimed at strengthening and completing the model. This thesis focuses on the interpretation of a dataset of reflection seismic profiles acquired during the 1970s in the area of the Northern Tyrrhenian Sea between the Elba Island and the Argentario promontory, by means of the MidlandValley Move and KogeoSeismic Toolkit software. This allowed to carry out two-dimensional and three-dimensional analyses of the profiles and to build 3D models of the main structures characterizing the Tuscany platform. The use of stratigraphic data from the Martina-1 and Mimosa-1 exploration wells and from the ground geology of the island of Pianosa, together with the analysis of the seismic profiles and the data deriving from the bibliographic study, enabled the reconstruction of the seismic stratigraphic succession of the area. We identified and described eight seismostratigraphic units separated by eight unconformities. Among these seismostratigraphic units, there are six post-orogenic units (Pa, Pb, Pc, Pd, Pe and Pq) representing the Neogenic succession covering the Tuscan platform, and two deeper Sub 1 and Sub 2 units representing the pre-Neogenic foundation. The analysis of the seismic profiles allowed to define the structural architecture of the Tuscany platform. The main structures of this platform are the Neogenic basins of Montecristo, Punta Ala and Uccellina, which extend along N-S and NE-SW trajectories and within which the post-orogenic seismostratigraphic units are deposited. The main contribution of this thesis work is the reconstruction of the tectonic-sedimentary evolution of the Tuscan platform, with specific reference to the basins and their relationship with previous compressive structures consisting of East thrust verges linked to the chain structuring processes in the Tyrrhenian sector. Several normal fault systems were identified and described, which consist of medium-high angle faults with predominantly NS and NE-SW direction and immersion both towards West and East, whose activation and deactivation drove the development of Neogenic basins. No normal listric and low angle fault systems were observed. Based on the results obtained from the detailed analysis of the seismic profiles and from their 3D modeling, an evolutionary model of the Tuscany platform was proposed. The formation of the Neogenic basins, resulting from of the extensional tectonic processes within the entire Tuscan shelf, began in the upper Burdigalian. The basins initially constitute intermontane basins developing along the flanks of the antiforms that derive from previous compressive tectonics. The initial position of the basins, over the forelimb or the backlimb of the thrust antiforms, influences the (respectively) asymmetrical or symmetrical shape along which the basins develop. Starting from the Messinian, there is a general vertical collapse of the platform, which leads to the deepening of the basins driven by the normal high-angle border faults. This process continues up to the lower Pliocene, when the deactivation of all normal faults is recorded, and conditions of widespread subsidence are witnessed throughout the platform together with the deposition of the two more superficial post-orogenic seismostratigraphic units (Pe, Pq). This thesis thus (i) reviews the tectonic evolution of the northern Tyrrhenian Sea and the previous extensional models proposed, (ii) questions both the mechanisms so far presented as responsible for the extensional processes, as well as the structures associated with them, and (iii) establishes a new starting point for the development of future work aimed at strengthening and completing the model. This thesis focuses on the interpretation of a dataset of reflection seismic profiles acquired during the 1970s in the area of the Northern Tyrrhenian Sea between the Elba Island and the Argentario promontory, by means of the MidlandValley Move and KogeoSeismic Toolkit software. This allowed to carry out two-dimensional and three-dimensional analyses of the profiles and to build 3D models of the main structures characterizing the Tuscany platform. The use of stratigraphic data from the Martina-1 and Mimosa-1 exploration wells and from the ground geology of the island of Pianosa, together with the analysis of the seismic profiles and the data deriving from the bibliographic study, enabled the reconstruction of the seismic stratigraphic succession of the area. We identified and described eight seismostratigraphic units separated by eight unconformities. Among these seismostratigraphic units, there are six post-orogenic units (Pa, Pb, Pc, Pd, Pe and Pq) representing the Neogenic succession covering the Tuscan platform, and two deeper Sub 1 and Sub 2 units representing the pre-Neogenic foundation. The analysis of the seismic profiles allowed to define the structural architecture of the Tuscany platform. The main structures of this platform are the Neogenic basins of Montecristo, Punta Ala and Uccellina, which extend along N-S and NE-SW trajectories and within which the post-orogenic seismostratigraphic units are deposited. The main contribution of this thesis work is the reconstruction of the tectonic-sedimentary evolution of the Tuscan platform, with specific reference to the basins and their relationship with previous compressive structures consisting of East thrust verges linked to the chain structuring processes in the Tyrrhenian sector. Several normal fault systems were identified and described, which consist of medium-high angle faults with predominantly NS and NE-SW direction and immersion both towards West and East, whose activation and deactivation drove the development of Neogenic basins. No normal listric and low angle fault systems were observed. Based on the results obtained from the detailed analysis of the seismic profiles and from their 3D modeling, an evolutionary model of the Tuscany platform was proposed. The formation of the Neogenic basins, resulting from of the extensional tectonic processes within the entire Tuscan shelf, began in the upper Burdigalian. The basins initially constitute intermontane basins developing along the flanks of the antiforms that derive from previous compressive tectonics. The initial position of the basins, over the forelimb or the backlimb of the thrust antiforms, influences the (respectively) asymmetrical or symmetrical shape along which the basins develop. Starting from the Messinian, there is a general vertical collapse of the platform, which leads to the deepening of the basins driven by the normal high-angle border faults. This process continues up to the lower Pliocene, when the deactivation of all normal faults is recorded, and conditions of widespread subsidence are witnessed throughout the platform together with the deposition of the two more superficial post-orogenic seismostratigraphic units (Pe, Pq). This thesis thus (i) reviews the tectonic evolution of the northern Tyrrhenian Sea and the previous extensional models proposed, (ii) questions both the mechanisms so far presented as responsible for the extensional processes, as well as the structures associated with them, and (iii) establishes a new starting point for the development of future work aimed at strengthening and completing the model. This thesis focuses on the interpretation of a dataset of reflection seismic profiles acquired during the 1970s in the area of the Northern Tyrrhenian Sea between the Elba Island and the Argentario promontory, by means of the MidlandValley Move and KogeoSeismic Toolkit software. This allowed to carry out two-dimensional and three-dimensional analyses of the profiles and to build 3D models of the main structures characterizing the Tuscany platform. The use of stratigraphic data from the Martina-1 and Mimosa-1 exploration wells and from the ground geology of the island of Pianosa, together with the analysis of the seismic profiles and the data deriving from the bibliographic study, enabled the reconstruction of the seismic stratigraphic succession of the area. We identified and described eight seismostratigraphic units separated by eight unconformities. Among these seismostratigraphic units, there are six post-orogenic units (Pa, Pb, Pc, Pd, Pe and Pq) representing the Neogenic succession covering the Tuscan platform, and two deeper Sub 1 and Sub 2 units representing the pre-Neogenic foundation. The analysis of the seismic profiles allowed to define the structural architecture of the Tuscany platform. The main structures of this platform are the Neogenic basins of Montecristo, Punta Ala and Uccellina, which extend along N-S and NE-SW trajectories and within which the post-orogenic seismostratigraphic units are deposited. The main contribution of this thesis work is the reconstruction of the tectonic-sedimenta
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- 2021
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