Search results for "Sediment"
showing 10 items of 1648 documents
Influence of artificial reefs on the surrounding infauna: Analysis of meiofauna
2002
We adopted a bottom-up approach in studying the effect of two artificial reefs in contrasting environmental conditions (sandy-mud and meso-eutrophic in the Adriatic Sea versus coarse sands and oligotrophic in the Tyrrhenian Sea) on the surrounding environment by assessing changes in the meiofauna. The spatial distribution of meiofaunal assemblages was established along a transect running from within each reef to well outside its direct sphere of influence, along with information on the trophic conditions of sediments (chloropigments, proteins, carbohydrates and total organic matter). Although total densities were significantly higher in the Adriatic than in the Tyrrhenian, the meiofauna dis…
Growth and geomorphic evolution of the Ustica volcanic complex at the Africa-Europe plate margin (Tyrrhenian Sea)
2021
18 pages, 13 figures, 1 table
Magmatism Along Lateral Slab Edges: Insights From the Diamante-Enotrio-Ovidio Volcanic-Intrusive Complex (Southern Tyrrhenian Sea)
2019
Volcanic‐intrusive complexes often formed along lateral slab edges as a consequence of subduction‐induced mantle flow. We investigate this process in the southern Tyrrhenian Sea by integrating multibeam bathymetry, seismic‐reflection data, regional magnetic anomalies data, and seismological data. The interpretation of the data highlights the presence of magmatic intrusions that locally reach the seafloor forming volcanic edifices. Chimneys, lava flows, and laccoliths are observed beneath and surrounding the volcanoes. The emplacement and cooling of the magma occurred during the Brunhes Chron. The volcanoes are not active even if the hydrothermal activity occurs. The volcanic‐intrusive compl…
Efectos de una crecida en un cauce antropizado. La riada del Palancia de octubre de 2000
2011
[EN] In October of 2000, the Palància River underwent a major flood, which substantially modified the morphology of the river channel. These changes took place on a river bed previously modified by public works aimed at cleaning and simplifying the river section. The flood partially restored the braided morphology, reconstructing bars and channels. Moreover, river incision processes increased, particularly downstream the Palància bridges. This process reveals a sedimentary deficit caused by reservoirs; land use changes and gravel mining. The aim of this work is to describe these processes of change and to analyze the morphosedimentary consequences, through the interpretation of aerial photo…
Los depósitos cuaternarios de L'Arenal de Petrer (Alicante)
1988
EN ESTE ARTICULO SE ESTUDIA LA GEOMORFOLOGIA Y LOS DEPOSITOS CUATERNARIOS DE UNA PEQUEÑA RAMBLA DE LA PROVINCIA DE ALICANTE, TRIBUTARIA DEL VINALOPO. DESDE LA PERSPECTIVA ESTRATIGRAFICA Y SEDIMENTOLOGICA, APOYADOS EN DATACIONES ABSOLUTAS DE C14 SE HA INTENTADO ESTABLECER LA SECUENCIA SEDIMENTARIA, QUE REFLEJA EL COMPORTAMIENTO DEL VALLE DURANTE LAS ULTIMAS PULSACIONES CLIMATICAS CUATERNARIAS. (A)
Le unità fisiografiche Paesaggistiche Costiere
2008
A facies distribution model controlled by a tectonically inherited sea bottom topography in the carbonate rimmed shelf of the Upper Tithonian–Valangi…
2016
The Upper Tithonian–Valanginian shallow-water carbonates outcropping in the Palermo Mts (NW Sicily) consist of several facies associations reflecting different depositional environments of a carbonate rimmed shelf, pertaining to the Southern Tethyan continental margin. The reconstructed depositional model, based on the sedimentological features, cyclic facies arrangement and biota distribution, shows that a wide protected lagoon, dominated by algae, molluscs and scattered patch reefs, was bordered landward by a tidal flat, where stromatolitic algal mats were cyclically subaerial exposed, and seaward by a marine sand belt and reef complex. Oolitic packstone-grainstone lithofacies, cyclically…
Natural and anthropogenic influences on the geochemistry of Quaternary lake sediments from Holzmaar, Germany
1997
The accumulation of heavy metals and trace elements has been investigated in a well laminated sequence of Holocene and late Pleistocene lake sediments composed of diatomaceous gyttja, tuff and silt and clay sediments. Varve chronology of the annually deposited gyttja yielded a continuous high-resolution time sequence and allowed the absolute age dating of the sediment. Fluxes of elements remained largely uniform from the late Pleistocene into the Holocene. Higher trace element and heavy metal fluxes occur from 2322 to 862 VT years ago (VT: varve time, years before 1950) and reached their maxima in the uppermost sediments (<845 VT years ago). These increasing element fluxes correlate with in…
Šarlotes ezera ekoloģiskā kvalitāte
2018
Bakalaura darba “Šarlotes ezera ekoloģiskā kvalitāte” mērķis ir raksturot Šarlotes ezera kvalitāti un tās uzlabošanas iespējas. Pētījuma objekts ir Šarlotes ezers, kurš atrodas Latgalē, Ilūkstes novada Šederes pagastā. Bakalaura darba teorētiskais pamatojums balstās uz zinātniskās literatūras analīzi par ezeriem, dabas ūdens sastāvu un to ietekmējošajiem faktoriem, piesārņojuma veidiem un avotiem, eitrofikācijas procesu, ezeru rekultivāciju, kā arī par Šarlotes ezeru un tā sateces baseinu. Bakalaura darba pētījuma praktiskajā daļā tika veikti lauka darbi Šarlotes ezerā gada griezumā, veicot ūdens un sedimentu paraugu ievākšanu un citu in-situ parametru noteikšanu. Ezera ūdenim tika noteikta…
The geographic information in the assessment of geohazard in the marine environment
2011
Slope instability and erosion, mass transport, volcanic and tectonic activity, fast sediment accumulation fluid escape are the main processes responsible for the geohazard in marine environment. A major knowledge about the geological setting of the offshore areas and related processes can be crucial to assess and manage the potential geological risks. High resolution morphobathymetric surveys, yielded in the frame of the MaGIC project (Marine Geohazards along the Italian Coasts), integrated with previously acquired data, single-channel seismic reflection profiles, backscatter data and sediments sampling, allow to define the geomorphological, stratigraphic and structural features in the offs…