After decades of hypotheses, a study conducted by INGV researchers provides evidence of the geological origin of the Peloritani Mountains in Sicily, identifying their "Iberian" origin with paleomagnetic analyses.
Between 150 and 120 million years ago, a large crustal block identified as a Plate Greater Iberia it detached itself from Europe and then fragmented, about 30 million years ago, in a major plate (“Iberia”) and in numerous microplates which, over time, have migrated eastwards for 500 km (constituting current Corsica and Sardinia) and 1000 km (today's Peloritani Mountains and Calabria).
This is what emerges from the study “Paleomagnetism of the Peloritan terrane (NE Sicily): From Greater Iberia to the Neo Apennine‐Maghrebide Arc” created by a team of researchers fromNational Institute of Geophysics and Volcanology (INGV), recently published in the magazine 'Tectonics'.
The so-called Calabro-Peloritano block it extends between the Nebrodi Mountains and the Peloritani Mountains of north-eastern Sicily and the Calabrian area south of the Pollino Massif. Its geology, completely different from that of the rest of the nearby Apennine and Sicilian chains, presents some similarities with the geology of the Sardinian-Corsican microplate, the Kabyle Blocks (Algeria) and the Iberian Plate (Spain and Portugal): this had led to the hypothesis, for decades, that all these crustal blocks were originally united. However, no evidence proving an “Iberian” origin of the Calabro-Peloritano Block had so far been documented.
“The study we have just published finally provides evidence of what the scientific community has long hypothesized”, explains Fabio Speranza, Director of the Roma2 Section of INGV and co-author of the study. “The data we collected, obtained from rock samples taken in Sicily, between Taormina and San Marco d'Alunzio, and analyzed in the INGV 'Renato Funiciello' Paleomagnetism Laboratory, highlighted that between 150 and 120 million years ago an anti-clockwise rotation of approximately 30° occurred in the magnetization of the samples. This is completely similar, both in terms of entity and chronology, to the rotation observed in the Iberian Plate when, during the process of 'opening' the Atlantic Ocean, broke away from the European Plate forming the Bay of Biscay”.
The fragmentation and eastward migration of the Sardinian-Corsican Microplate, of the Kabyle Blocks and, later, of the Calabro-Peloritano Block would have occurred during the opening of the new Ligurian-Provençal ocean basins (which occurred between 30 and 15 million years ago) and Tyrrhenian (between 10 and 2 million years ago), synchronously with the formation of the Apennine and Sicilian chains.
“Geological data show that the Peloritano Block was incorporated into the Sicilian mountain range between 18 and 17 million years ago”, explains Gaia Siravo, researcher at INGV and co-author of the study. “The paleomagnetic data, in turn, show that the total post-Oligocene rotation (post-23 million years ago) of the Block is equal to 130° per hour, exactly superimposable on that already widely documented in central-western Sicily and linked to structuring of the Sicilian chain itself and the opening of the Tyrrhenian Sea. This clockwise rotation is, however, completely different from the anti-clockwise rotation (of around 140°) already documented by us two years ago on sediments emerging in eastern Sila. This allowed us to provide further evidence: the Calabro-Peloritano Block is actually composed of two micro-blocks that have had a completely different evolution over the last 30 million years"he concludes Siravo.
Link to the study:
Useful links:
National Institute of Geophysics and Volcanology (INGV)
Between 150 and 120 million years ago, a large crustal block identified as a Plate Greater Iberia it detached itself from Europe and then fragmented, about 30 million years ago, in a major plate (“Iberia”) and in numerous microplates which, over time, have migrated eastwards for 500 km (constituting current Corsica and Sardinia) and 1000 km (today's Peloritani Mountains and Calabria).
This is what emerges from the study “Paleomagnetism of the Peloritan terrane (NE Sicily): From Greater Iberia to the Neo Apennine‐Maghrebide Arc” created by a team of researchers fromNational Institute of Geophysics and Volcanology (INGV), recently published in the magazine 'Tectonics'.
The so-called Calabro-Peloritano block it extends between the Nebrodi Mountains and the Peloritani Mountains of north-eastern Sicily and the Calabrian area south of the Pollino Massif. Its geology, completely different from that of the rest of the nearby Apennine and Sicilian chains, presents some similarities with the geology of the Sardinian-Corsican microplate, the Kabyle Blocks (Algeria) and the Iberian Plate (Spain and Portugal): this had led to the hypothesis, for decades, that all these crustal blocks were originally united. However, no evidence proving an “Iberian” origin of the Calabro-Peloritano Block had so far been documented.
“The study we have just published finally provides evidence of what the scientific community has long hypothesized”, explains Fabio Speranza, Director of the Roma2 Section of INGV and co-author of the study. “The data we collected, obtained from rock samples taken in Sicily, between Taormina and San Marco d'Alunzio, and analyzed in the INGV 'Renato Funiciello' Paleomagnetism Laboratory, highlighted that between 150 and 120 million years ago an anti-clockwise rotation of approximately 30° occurred in the magnetization of the samples. This is completely similar, both in terms of entity and chronology, to the rotation observed in the Iberian Plate when, during the process of 'opening' the Atlantic Ocean, broke away from the European Plate forming the Bay of Biscay”.
The fragmentation and eastward migration of the Sardinian-Corsican Microplate, of the Kabyle Blocks and, later, of the Calabro-Peloritano Block would have occurred during the opening of the new Ligurian-Provençal ocean basins (which occurred between 30 and 15 million years ago) and Tyrrhenian (between 10 and 2 million years ago), synchronously with the formation of the Apennine and Sicilian chains.
“Geological data show that the Peloritano Block was incorporated into the Sicilian mountain range between 18 and 17 million years ago”, explains Gaia Siravo, researcher at INGV and co-author of the study. “The paleomagnetic data, in turn, show that the total post-Oligocene rotation (post-23 million years ago) of the Block is equal to 130° per hour, exactly superimposable on that already widely documented in central-western Sicily and linked to structuring of the Sicilian chain itself and the opening of the Tyrrhenian Sea. This clockwise rotation is, however, completely different from the anti-clockwise rotation (of around 140°) already documented by us two years ago on sediments emerging in eastern Sila. This allowed us to provide further evidence: the Calabro-Peloritano Block is actually composed of two micro-blocks that have had a completely different evolution over the last 30 million years"he concludes Siravo.
Link to the study:
Useful links:
National Institute of Geophysics and Volcanology (INGV)
Fig.1: The two hypotheses existed before the study recently published on 'Tectonics' (palaeogeography to 145 Ma). Hypothesis a), supported by the authors, indicates Calabria, Monti Peloritani and southern Sardinia in solidarity with Iberia (Greater Iberia); hypothesis b), not supported by the data collected by the authors, instead indicates Sardinia, Calabria and the Peloritani Mountains in solidarity with the European Plate.
Fig.2: Paleogeography at 21 Ma, with Sardinia, Calabria and Peloritani still in solidarity with each other but already detached from Iberia.
Fig.3: A moment of rock sampling.