scholarly journals The Depositional Environments in the Cilento Offshore (Southern Tyrrhenian Sea, Italy) Based on Marine Geological Data

2021 ◽  
Vol 9 (10) ◽  
pp. 1083
Author(s):  
Gemma Aiello ◽  
Mauro Caccavale
Keyword(s):  
Continental Shelf ◽  
Late Quaternary ◽  
Depositional Environments ◽  
Geological Mapping ◽  
Outer Shelf ◽  
Tyrrhenian Sea ◽  
Outer Continental Shelf ◽  
Inner Shelf ◽  
Depositional Sequence ◽  
System Tract

The depositional environments offshore of the Cilento Promontory have been reconstructed based on the geological studies performed in the frame of the marine geological mapping of the geological sheet n. 502 “Agropoli”. The littoral environment (toe-of-coastal cliff deposits and submerged beach deposits), the inner continental shelf environment (inner shelf deposits and bioclastic deposits), the outer continental shelf environment (outer shelf deposits and bioclastic deposits), the lowstand system tract and the Pleistocene relict marine units have been singled out. The littoral, inner shelf and outer shelf environments have been interpreted as the highstand system tract of the Late Quaternary depositional sequence. This sequence overlies the Cenozoic substratum (ssi unit), composed of Cenozoic siliciclastic rocks, genetically related with the Cilento Flysch. On the inner shelf four main seismo-stratigraphic units, overlying the undifferentiated acoustic basement have been recognized based on the geological interpretation of seismic profiles. On the outer shelf, palimpsest deposits of emerged to submerged beach and forming elongated dunes have been recognized on sub-bottom profiles and calibrated with gravity core data collected in previous papers. The sedimentological analysis of sea bottom samples has shown the occurrence of several grain sizes occurring in this portion of the Cilento offshore.

scholarly journals Marine geological maps of the Campania region (Southern Tyrrhenian Sea, Italy): Considerations and contributions to a different scale of geological survey

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gemma Aiello
Keyword(s):  
Late Quaternary ◽  
Environmental Data ◽  
Geological Survey ◽  
Volcanic Area ◽  
Tyrrhenian Sea ◽  
Inner Shelf ◽  
Acoustic Basement ◽  
Campania Region ◽  
Geological Maps ◽  
Southern Tyrrhenian Sea

Marine geological maps of the Campania region have been constructed both to a 1:25.000 and to a 1:10.000 scale in the frame of the research projects financed by the Italian National Geological Survey, focusing, in particular, on the Gulf of Naples (Southern Tyrrhenian Sea), a complex volcanic area where volcanic and sedimentary processes strongly interacted during the Late Quaternary and on the Cilento Promontory offshore. In this paper, the examples of the geological sheets n. 464 “Isola di Ischia” and n. 502 “Agropoli” have been studied. The integration of the geological maps with the seismo-stratigraphic setting of the study areas has also been performed based on the realization of interpreted seismic profiles, providing interesting data on the geological setting of the subsurface. The coastal geological sedimentation in the Ischia and Agropoli offshore has been studied in detail. The mapped geological units are represented by: i) the rocky units of the acoustic basement (volcanic and/or sedimentary); ii) the deposits of the littoral environment, including the deposits of submerged beach and the deposits of toe of coastal cliff; iii) the deposits of the inner shelf environment, including the inner shelf deposits and the bioclastic deposits; iv) the deposits of the outer shelf environment, including the clastic deposits and the bioclastic deposits; v) the lowstand system tract; vi) the Pleistocene relict marine units; vii) different volcanic units in Pleistocene age. The seismo-stratigraphic data, coupled with the sedimentological and environmental data provided by the geological maps, provided us with new insights on the geologic evolution of this area during the Late Quaternary.

Analysis of the postglacial deposits of the Rhône shelf (golfe du Lion). Implementation to the study of the late Quaternary depositional sequences

2003 ◽  
Vol 174 (4) ◽  
pp. 401-419 ◽  
Author(s):  
Bernard Gensous ◽  
Michel Tesson
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Late Quaternary ◽  
Sediment Supply ◽  
Ocean Dynamics ◽  
Outer Shelf ◽  
Inner Shelf ◽  
Depositional Sequences ◽  
Incised Valley ◽  
Deltaic Plain

Abstract Postglacial deposits of the Rhône shelf have been studied from high-resolution seismic data and Kullenberg piston cores. They are organised into a set of transgressive units or parasequences backstepping from the outer shelf to the subaerial deltaic plain. On the deltaic plain, they are overlain by the prograding deltaic parasequences deposited at the end of the Holocene sea level rise. At regional scale, given the short time span covered by the late Quaternary deposits, tectonic subsidence has played a minor role and sediment deposition on the Rhône shelf was chiefly controlled by glacio-eustatic sea level changes (120 m between the maximum lowstand and present highstand). Progradational phases correspond to periods of reduced rate of eustatic sea level rise while the flooding surfaces bounding the regressive units form during periods of increasing rate of sea level rise and landward shoreline migration. At local scale, location, geometry, nature of deposits, and lateral variations of the stratigraphic pattern are controlled by the interaction between eustasy and local factors as sediment supply, antecedent morphology and ocean dynamics. Seaward of the Rhône river, terrigenous input was important during deglaciation and transgressive deposits extend continuously from the outer shelf to the inner shelf along the retreating path of the paleo-Rhône river mouth. Laterally, on either side of the Rhône incised valley, because of the reduced sediment supply, parasequences only develop on the outer shelf and inner shelf : the combination of the very low inherited gradient of the mid/outer shelf and a very high rate of sea level rise favoured a very rapid migration of the shoreline from outer to inner shelf. Ocean dynamics has been controlled, as in present time, by the E to SE prevailing waves that are the only ones which can develop on an extended fetch. The westward alongshore drift accounted for the development of parasequences west of the incised valley. The sandy material needed for the construction of the outershelf parasequence was supplied by wave-reworking and westward long-shore drift of deposits from the Rhône delta front and the uppermost forced regressive unit. The decreasing sand content of parasequences from outer shelf to inner shelf results from flattening of the equilibrium river profile that led to a decrease in competence and a change in the character of the sediment caliber (relative increase of suspension load). The underlying Pleistocene depositional sequences comprise both lowstand prograding units, that characterize most of the Mediterranean shelves, and intercalated units which are analogs of the postglacial transgressive deposits here presented.

Zonation of demersal fishes off Anvers Island, western Antarctic Peninsula

2015 ◽  
Vol 28 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Margaret O. Amsler ◽  
Joseph T. Eastman ◽  
Kathryn E. Smith ◽  
James B. Mcclintock ◽  
Hanumant Singh ◽  
...  
Keyword(s):  
Fish Fauna ◽  
Antarctic Fish ◽  
Abundant Species ◽  
Outer Shelf ◽  
Outer Continental Shelf ◽  
Absolute Abundance ◽  
Inner Shelf ◽  
Photographic Survey ◽  
Upper Slope ◽  
Demersal Fishes

AbstractThe Antarctic fish fauna from outer continental shelf/upper slope depths is under-sampled compared to that of the inner shelf, and there are limited quantitative data available on absolute abundance and taxonomic change with depth. A photographic survey of demersal fishes was conducted along a depth-gradient of 400–2099 m on the outer shelf and upper slope west of Anvers Island, Palmer Archipelago. A total of 1490 fishes were identified at least to the family level. Notothenioids composed 52.7% of absolute abundance and non-notothenioids 47.3%. The most abundant families were Nototheniidae (39.4%), followed by Macrouridae (28.9%), Zoarcidae (16.9%), and Channichthyidae (12.1%). The most abundant species were the notothenioidsLepidonotothen squamifrons(30.5%) andChionobathyscus dewitti(11.7%), and the non-notothenioidMacrourusspp. (29.5%). The absolute abundance of all fishes peaked at 400–599 m. Depths of maximum abundance were 400–599 m forL. squamifrons, 700–1499 m forMacrourusspp., and 900–1499 forC. dewitti. At 700–999 m the abundance shifted from primarily notothenioids to the non-notothenioidsMacrourusspp. and zoarcids. Fishes of the outer shelf and upper slope are not provincialized like those of the inner shelf and are circum-Antarctic.

scholarly journals Marine geological maps of the Campania Region (Southern Tyrrhenian sea, Italy): considerations and contributions to a different scale of geological survey

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Gemma Aiello
Keyword(s):  
Late Quaternary ◽  
Environmental Data ◽  
Geological Survey ◽  
Volcanic Area ◽  
Tyrrhenian Sea ◽  
Inner Shelf ◽  
Acoustic Basement ◽  
Campania Region ◽  
Geological Maps ◽  
Southern Tyrrhenian Sea

Marine geological maps of the Campania region have been constructed both to 1:25.000 and to a 1:10.000 scales in the frame of research projects financed by the Italian National Geological Survey, focusing, in particular, on the Gulf of Naples (Southern Tyrrhenian sea), a complex volcanic area where volcanic and sedimentary processes strongly interacted during the Late Quaternary and on the Cilento Promontory offshore. In this paper the examples of the geological sheets n. 464 “Isola di Ischia” and n. 502 “Agropoli” have been studied. The integration of the geological maps with the seismo-stratigraphic setting of the study areas has also been performed based on the realization of interpreted seismic profiles, providing interesting data on the geological setting of the subsurface. The coastal geological sedimentation has been studied in detail in the Ischia and Agropoli offshore. The mapped geological units are represented by: i) the rocky units of the acoustic basement (volcanic and/or sedimentary), ii) the deposits of the littoral environment, including the deposits of submerged beach and the deposits of toe of coastal cliff, iii) the deposits of the inner shelf environment, including the inner shelf deposits and the bioclastic deposits, iv) the deposits of the outer shelf environment, including the clastic deposits and the bioclastic deposits, v) the Lowstand System Tract, vi) the Pleistocene relict marine units, vii) different volcanic units, Pleistocene in age. The seismo-stratigraphic data, coupled with the sedimentological and environmental data provided by the geological maps, allow to give new insights on the geologic evolution of this area during the Late Quaternary. 

Late Quaternary Paleoceanography of the Mid- to Outer Continental Shelf, East Greenland

1995 ◽  
Vol 27 (4) ◽  
pp. 352 ◽  
Author(s):  
K. M. Williams ◽  
J. T. Andrews ◽  
N. J. Weiner ◽  
P. J. Mudie
Keyword(s):  
Continental Shelf ◽  
Late Quaternary ◽  
Outer Continental Shelf ◽  
East Greenland

Late Quaternary Tectonics vs Sedimentation history of the offshore Termini in a seismically active segment of the Northern Sicily Continental margin (Southern Tyrrhenian Sea)

2020 ◽  
Author(s):  
Elisabetta Zizzo ◽  
Attilio Sulli ◽  
Daniele Spatola ◽  
Christian Gorini ◽  
Maurizio Gasparo Morticelli
Keyword(s):  
High Resolution ◽  
Continental Margin ◽  
Late Quaternary ◽  
Mass Movement ◽  
Strike Slip ◽  
Seismic Facies ◽  
Tyrrhenian Sea ◽  
Depositional Sequence ◽  
Coastal Belt ◽  
Southern Tyrrhenian Sea

<p>We investigate the tectonically active Northern Sicily Continental margin focusing on the neotectonics affecting the Offshore of Termini (Southern Tyrrhenian Sea) by using high-resolution seismic and multibeam data. The sedimentary succession along the North Sicilian Continental Margin (NSCM) represents the marine prolongation of those outcropping along the Northern Sicily coastal belt. The NSCM has been originated as a consequence of a complex interaction of compressional events, crustal thinning, and strike-slip faulting. E–W, NW–SE, and NE–SW trending, both extensional and compressional faults, with a local strike-slip component, exerted control on the morphology of the present-day shelf and coastal areas during the Pleistocene. During the Quaternary,  the tectonic as well as depositional events have strongly shaped the margin forming the actual complex geomorphic setting of the margin. We present the main results of a high resolution survey that allow to identify several features (e.g. Mass Transport Deposits and pockmarks) linked to gravitational mass movement and fluids escape processes strongly controlled by the tectonics affecting the NSCM. All over the study area, we mapped inside the Late Quaternary depositional sequence repeated and variously distributed MTDs, characterised by transparent/chaotic seismic facies, interbedded to hemipelagic deposits, with seismic facies showing subparallel seismic reflectors of the transgressive and high stand systems tracts. We infer that this MTDs have been seismically induced by earthquakes.  We estimate the recurrence times of earthquakes, by using an elaborate age-model that considers a constant sedimentation rate for the last 11.5 My, between 680 and 2200 years.</p>

Echinoidea of Oregon

1967 ◽  
Vol 24 (6) ◽  
pp. 1385-1401 ◽  
Author(s):  
James E. McCauley ◽  
Andrew G. Carey Jr.
Keyword(s):  
Continental Shelf ◽  
Deep Water ◽  
Strongylocentrotus Purpuratus ◽  
Outer Shelf ◽  
Shallow Waters ◽  
Outer Continental Shelf ◽  
Geographic Ranges ◽  
Dendraster Excentricus ◽  
Upper Slope

Ten species of echinoids are known to occur off Oregon. Three distinct bathymetric groups are recognized: Strongylocentrotus purpuratus, S. franciscanus, and Dendraster excentricus occur in shallow waters from intertidal down to about 65 m; S. echinoides occurs on the outer continental shelf, and Brisaster latifrons and Allocentrotus fragilis occur on the outer shelf and upper slope at depths of about 70–840 m; and Aëropsis fulva, Sperosoma giganteum, Urechinus loveni, and Ceratophysa rosea are found in deep water from depths of 2090 to 3000 m. Bathymetric ranges are extended for six species and geographic ranges are extended for five species.

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