Morpho-depositional units of the southern Ischia canyon system, engraving the continental slope offshore southern Ischia island and their influence on the erosional processes active in the coastal systems of Ischia are here discussed. The southern Ischia canyon system, investigated through bathymetric and seismic data, is incised on a narrow continental shelf ranging from Punta Imperatore to Punta S. Pancrazio (S Ischia). The canyon system is made of 22 drainage axes having variable extension and planimetric trending, reconstructed through the geological interpretation of Multibeam bathymetry. The margins of the canyon system appear to be controlled by different geological processes. The eastern boundary of the canyon system is tectonically-controlled, being located in correspondence to a NE-SW (counter-Apenninic) normal fault. On the contrary, its western margin is related to volcanism, being limited by Ischia monogenetic submarine volcano, whose age dating is relatively unknown. Morpho-depositional systems of the Tyrrhenian sea have been studied in detail through the recognition and mapping of submarine morphological lineaments in continental slope and bathyal plain environments. The Multibeam geological interpretation has represented a useful tool to provide a detailed interpretation of morphological and sedimentary features, being extensively used in geological studies on deep sea depositional systems. A full integration in the determination of the geologic characteristics of deep sea depositional systems was permitted by the application of the techniques of seismic stratigraphy and volcanic geomorphology. The meaning of volcanic geomorphology has been improved through the introduction of quantitative classifications of volcanic landforms, based on morphometry and studies based on ground observations, remote sensing data and laboratory experiments. These classifications have been combined with the data derived from Digital Elevation Models in order to carry out the morphological analysis of volcanoes. Detailed geomorphological maps of volcanoes can be produced, expanding the use of accurate chronological framework and compositional data through eruptive sequences. The expansion of capability of geomorphology in landscape history reconstruction has contributed to the understanding of processes of building and destruction of volcanic edifices and to the analysis of structural factors contributing to the catastrophic collapses of volcanoes. This technique has allowed to identify the sedimentary facies associations and facies models for volcano-sedimentary systems and to establish criteria for the recognition of volcanic deposits in old volcanic successions, inferring the role of climatic and tectonic effects on transport and deposition. The offshore surrounding Punta Imperatore-Capo Negro is characterized by three main submarine canyons, NE-SW trending, whose emplacement has been probably controlled by counter-Apenninic normal faults. This evidence well fits with previous structural studies, suggesting the occurrence of NE-SW extensional faults in the Ischia island. The Maronti canyons exhibit a N-S trending and begin in correspondence to some embayments of the retreated and eroded shelf break. A long canyon has been identified in correspondence to the Punta San Pancrazio promontory. Another main canyon is located in correspondence to the Ischia bank volcanic edifice. The canyon systems strongly controlled the erosional processes active in the coastal area through continuous sediment transport from shelf to basin.
Morpho-depositional units of the southern Ischia canyon system and their influence on the erosional processes in southern Ischia (Naples Bay)
2015
Abstract
Morpho-depositional units of the southern Ischia canyon system, engraving the continental slope offshore southern Ischia island and their influence on the erosional processes active in the coastal systems of Ischia are here discussed. The southern Ischia canyon system, investigated through bathymetric and seismic data, is incised on a narrow continental shelf ranging from Punta Imperatore to Punta S. Pancrazio (S Ischia). The canyon system is made of 22 drainage axes having variable extension and planimetric trending, reconstructed through the geological interpretation of Multibeam bathymetry. The margins of the canyon system appear to be controlled by different geological processes. The eastern boundary of the canyon system is tectonically-controlled, being located in correspondence to a NE-SW (counter-Apenninic) normal fault. On the contrary, its western margin is related to volcanism, being limited by Ischia monogenetic submarine volcano, whose age dating is relatively unknown. Morpho-depositional systems of the Tyrrhenian sea have been studied in detail through the recognition and mapping of submarine morphological lineaments in continental slope and bathyal plain environments. The Multibeam geological interpretation has represented a useful tool to provide a detailed interpretation of morphological and sedimentary features, being extensively used in geological studies on deep sea depositional systems. A full integration in the determination of the geologic characteristics of deep sea depositional systems was permitted by the application of the techniques of seismic stratigraphy and volcanic geomorphology. The meaning of volcanic geomorphology has been improved through the introduction of quantitative classifications of volcanic landforms, based on morphometry and studies based on ground observations, remote sensing data and laboratory experiments. These classifications have been combined with the data derived from Digital Elevation Models in order to carry out the morphological analysis of volcanoes. Detailed geomorphological maps of volcanoes can be produced, expanding the use of accurate chronological framework and compositional data through eruptive sequences. The expansion of capability of geomorphology in landscape history reconstruction has contributed to the understanding of processes of building and destruction of volcanic edifices and to the analysis of structural factors contributing to the catastrophic collapses of volcanoes. This technique has allowed to identify the sedimentary facies associations and facies models for volcano-sedimentary systems and to establish criteria for the recognition of volcanic deposits in old volcanic successions, inferring the role of climatic and tectonic effects on transport and deposition. The offshore surrounding Punta Imperatore-Capo Negro is characterized by three main submarine canyons, NE-SW trending, whose emplacement has been probably controlled by counter-Apenninic normal faults. This evidence well fits with previous structural studies, suggesting the occurrence of NE-SW extensional faults in the Ischia island. The Maronti canyons exhibit a N-S trending and begin in correspondence to some embayments of the retreated and eroded shelf break. A long canyon has been identified in correspondence to the Punta San Pancrazio promontory. Another main canyon is located in correspondence to the Ischia bank volcanic edifice. The canyon systems strongly controlled the erosional processes active in the coastal area through continuous sediment transport from shelf to basin.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
