The CARG Project, carried out since the 1999 at the Institute of Marine Coastal Environment of Naples, Italy, represents one of the most significant research projects in the last decade activities. The scientific and technological know-how of the Institute has found a wide expression performing acquisition surveys, processing and geologic interpretation and has allowed the redaction of sea bottom and subbottom marine geologic cartography of the Campania region from 1.50.000 to 1.10.000 scale. In particular, the geological map n. 502 "Agropoli" is here discussed. Geophysical and geological data on the continental shelf and slope have been recorded and interpreted in the Salerno and Policastro Gulfs. A high resolution Multibeam bathymetry allowed for the construction of a marine Digital Elevation Model; Sidescan Sonar acoustic data have been acquired for a total coverage of the study area, in order to construct photo-mosaics of acoustic images of sea bottom. The latter ones, merged to the bathymetry, have represented the base for the marine geologic cartography. The integrated geologic interpretation of seismic, bathymetric and Sidescan Sonar data have been suitably calibrated by sea bottom samples. The geological structures and the seismic sequences, overlying wide outcrops of rocky acoustic basement recognized in the marine sector of the 502 Agropoli geological map have been studied in detail using multichannel and single channel seismics of different resolution and penetration, including Subbottom Chirp profiles. The interpretation of high resolution seismic profiles (mainly Subbottom Chirp) was a valid support for the reconstruction of structural and stratigraphic setting of the Quaternary successions of continental shelf in the marine area included in the 502 Agropoli geological map and of the wide outcrops of rocky acoustic basement in correspondence to Punta Licosa morpho-structural high. These areas result from the seaward prolongation of the structural-stratigraphic units cropping out onshore in the adjacent emerged sector of the Cilento Promontory (Flysch del Cilento Auct.). The realized cartographic approach, perhaps experimental, is based on the recognition of depositional systems, laterally coeval, put into the context of the systems tracts of the Late Quaternary Depositional Sequence. The seismic units have been then interpreted in terms of depositional sequences and the unconformities have been interpreted as Type 1 and Type 2 sequence boundaries or classified in terms of local unconformities, mainly at the top of pockets of coarse-grained materials deposited into depressions or palaeo-channels located at the top of the acoustic basement. Polyciclic unconformities occur at the top of the acoustic basement, as evidenced by the terraced surfaces located at several heights, which erode the acoustic substratum. This perhaps has been subjected to several phases of emersion/erosion, development of terraces and progressive flooding as a consequence of glacio-eustatic sea level fluctuations during the Late Quaternary and of the Pleistocene uplift involving the study area. The realized geological map, according to CARG guidelines shows the distribution of the different lithostratigraphic units cropping out at the sea bottom and the main morphological lineaments. The main stratigraphic units individuated through the analysis of the sea bottom sediments belong to the Late Quaternary Depositional Sequence. In this sequence, the space and time evolution and the lateral and vertical migration of coastal marine, continental shelf and slope depositional environments of the Late Pleistocene-Holocene glacio-eustatic cycle have been recognized. The stratigraphic succession, studied through geological survey records the variations of the accommodation space of the Late Quaternary deposits during the last 4th order glacio-eustatic cycle, ranging between 128 ka (Tyrrhenian stage) and the actual (isotopic stage Q5e).
The Geological Map n. 502 "Agropoli" (scale 1:50.000): an example of cartographic representation of marine areas in the Campania offshore
Gemma Aiello;Bruno D'Argenio;Ennio Marsella
2012
Abstract
The CARG Project, carried out since the 1999 at the Institute of Marine Coastal Environment of Naples, Italy, represents one of the most significant research projects in the last decade activities. The scientific and technological know-how of the Institute has found a wide expression performing acquisition surveys, processing and geologic interpretation and has allowed the redaction of sea bottom and subbottom marine geologic cartography of the Campania region from 1.50.000 to 1.10.000 scale. In particular, the geological map n. 502 "Agropoli" is here discussed. Geophysical and geological data on the continental shelf and slope have been recorded and interpreted in the Salerno and Policastro Gulfs. A high resolution Multibeam bathymetry allowed for the construction of a marine Digital Elevation Model; Sidescan Sonar acoustic data have been acquired for a total coverage of the study area, in order to construct photo-mosaics of acoustic images of sea bottom. The latter ones, merged to the bathymetry, have represented the base for the marine geologic cartography. The integrated geologic interpretation of seismic, bathymetric and Sidescan Sonar data have been suitably calibrated by sea bottom samples. The geological structures and the seismic sequences, overlying wide outcrops of rocky acoustic basement recognized in the marine sector of the 502 Agropoli geological map have been studied in detail using multichannel and single channel seismics of different resolution and penetration, including Subbottom Chirp profiles. The interpretation of high resolution seismic profiles (mainly Subbottom Chirp) was a valid support for the reconstruction of structural and stratigraphic setting of the Quaternary successions of continental shelf in the marine area included in the 502 Agropoli geological map and of the wide outcrops of rocky acoustic basement in correspondence to Punta Licosa morpho-structural high. These areas result from the seaward prolongation of the structural-stratigraphic units cropping out onshore in the adjacent emerged sector of the Cilento Promontory (Flysch del Cilento Auct.). The realized cartographic approach, perhaps experimental, is based on the recognition of depositional systems, laterally coeval, put into the context of the systems tracts of the Late Quaternary Depositional Sequence. The seismic units have been then interpreted in terms of depositional sequences and the unconformities have been interpreted as Type 1 and Type 2 sequence boundaries or classified in terms of local unconformities, mainly at the top of pockets of coarse-grained materials deposited into depressions or palaeo-channels located at the top of the acoustic basement. Polyciclic unconformities occur at the top of the acoustic basement, as evidenced by the terraced surfaces located at several heights, which erode the acoustic substratum. This perhaps has been subjected to several phases of emersion/erosion, development of terraces and progressive flooding as a consequence of glacio-eustatic sea level fluctuations during the Late Quaternary and of the Pleistocene uplift involving the study area. The realized geological map, according to CARG guidelines shows the distribution of the different lithostratigraphic units cropping out at the sea bottom and the main morphological lineaments. The main stratigraphic units individuated through the analysis of the sea bottom sediments belong to the Late Quaternary Depositional Sequence. In this sequence, the space and time evolution and the lateral and vertical migration of coastal marine, continental shelf and slope depositional environments of the Late Pleistocene-Holocene glacio-eustatic cycle have been recognized. The stratigraphic succession, studied through geological survey records the variations of the accommodation space of the Late Quaternary deposits during the last 4th order glacio-eustatic cycle, ranging between 128 ka (Tyrrhenian stage) and the actual (isotopic stage Q5e).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
