New constraints on seismic stratigraphy and morpho-bathymetry of Southern Campania continental margin southwards of the structural elongment Capri Island-Sorrento Peninsula are here presented. High resolution multichannel seismics and Multibeam swath bathymetry have been recently collected by the CNR-IAMC Institute onboard of the R/V Urania (National Research Council of Italy) during the oceanographic cruise SISTERII. Marine geophysical data acquisition has been carried out in water depths ranging from - 100 m and - 1000 m, tied on research themes focused on integrated geological interpretation of multichannel seismics and Multibeam bathymetry. Main aims of the cruise were the identification of main morpho-structures both in slope and bathyal plain settings through Multibeam bathymetry and their correlation with seismic sequences identified based on structural and stratigraphic interpretation of multichannel reflection seismics. Multibeam acquisition has been performed by the RESON Seabat 8160 in dotation to the R/V Urania, realising a coverage of 50% between swaths and navigation lines parallel to the isobaths. The line spacing of Multibeam survey, varying as a function of water depths, ranges between about 500 m (for water depths of 100 m) and 1 km (for water depths of 800 m). Subbottom Chirp profiles have been recorded on the same navigation lines of bathymetry, in order to calibrate the morpho-structures evident by Multibeam bathymetry. Moreover, the acquisition of seven multichannel profiles has been carried out by using as seismic source two G/I Airguns (SSI Sodera) in dotation to the CNR-IAMC Institute of Naples, Italy, which allowed a good penetration of the sedimentary successions. The interpretation of high resolution seismic profile L7 has shown several seismic units and related unconformities. In particular, a main unconformity, located at about 1.7-1.8 sec of depth has been interpreted as the top of the Meso-Cenozoic carbonate sequence, widely cropping out in the Sorrento Peninsula structural high. Pleistocene basin filling of the Salerno Valley overlies this unconformity and shows a thickness of about - 500 m. The seismic sequences of the Salerno Valley are characterized by wedging and synsedimentary tectonics in correspondence to a NW-SE trending morphostructural high, well evident in Multibeam bathymetry. This high is located next to a strong shelf break, which outlines the transition to distal areas, showing water depths ranging between - 750 m and - 1100 m. Chaotic intervals alternating to well continuous and stratified seismic reflectors suggest the occurrence of gravitational mass transport episodes during a normal marine sedimentation. Actually the dataset is the object of a quantitative geological and structural study; the results will be compared with other structural studies carried out in the area.
A high resolution regional seismic profile on southern Campania continental margin: constraints on seismic stratigraphy and morphobathymetry of the Salerno Valley (southern Tyrrhenian sea, Italy)
Gemma Aiello;Vincenzo Di Fiore;Ennio Marsella;
2007
Abstract
New constraints on seismic stratigraphy and morpho-bathymetry of Southern Campania continental margin southwards of the structural elongment Capri Island-Sorrento Peninsula are here presented. High resolution multichannel seismics and Multibeam swath bathymetry have been recently collected by the CNR-IAMC Institute onboard of the R/V Urania (National Research Council of Italy) during the oceanographic cruise SISTERII. Marine geophysical data acquisition has been carried out in water depths ranging from - 100 m and - 1000 m, tied on research themes focused on integrated geological interpretation of multichannel seismics and Multibeam bathymetry. Main aims of the cruise were the identification of main morpho-structures both in slope and bathyal plain settings through Multibeam bathymetry and their correlation with seismic sequences identified based on structural and stratigraphic interpretation of multichannel reflection seismics. Multibeam acquisition has been performed by the RESON Seabat 8160 in dotation to the R/V Urania, realising a coverage of 50% between swaths and navigation lines parallel to the isobaths. The line spacing of Multibeam survey, varying as a function of water depths, ranges between about 500 m (for water depths of 100 m) and 1 km (for water depths of 800 m). Subbottom Chirp profiles have been recorded on the same navigation lines of bathymetry, in order to calibrate the morpho-structures evident by Multibeam bathymetry. Moreover, the acquisition of seven multichannel profiles has been carried out by using as seismic source two G/I Airguns (SSI Sodera) in dotation to the CNR-IAMC Institute of Naples, Italy, which allowed a good penetration of the sedimentary successions. The interpretation of high resolution seismic profile L7 has shown several seismic units and related unconformities. In particular, a main unconformity, located at about 1.7-1.8 sec of depth has been interpreted as the top of the Meso-Cenozoic carbonate sequence, widely cropping out in the Sorrento Peninsula structural high. Pleistocene basin filling of the Salerno Valley overlies this unconformity and shows a thickness of about - 500 m. The seismic sequences of the Salerno Valley are characterized by wedging and synsedimentary tectonics in correspondence to a NW-SE trending morphostructural high, well evident in Multibeam bathymetry. This high is located next to a strong shelf break, which outlines the transition to distal areas, showing water depths ranging between - 750 m and - 1100 m. Chaotic intervals alternating to well continuous and stratified seismic reflectors suggest the occurrence of gravitational mass transport episodes during a normal marine sedimentation. Actually the dataset is the object of a quantitative geological and structural study; the results will be compared with other structural studies carried out in the area.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
