Search results for " Sediment"
showing 10 items of 762 documents
Submarine Slope Failures Along the Northern Sicilian Continental Margin (Southern Tyrrhenian Sea) and Possible Implications for Geo-Hazard
2013
Mass wasting and downslope movements are common processes that have contributed to shape the northern Sicilian continental margin (southern Tyrrhenian Sea) since the Late Quaternary. Nevertheless, processes controlling their evolution are still partially unknown and a variety of geologic factors can be responsible for their formation. In this work we present an overview of the main mass wasting features (submarine canyons, landslides, debris flows) observed and mapped in different sectors of the northern Sicilian margin. The margin is characterized by a narrow, steep continental shelf (1-2°) and a very irregular and steep (6-8°) upper slope. The main aims of this work are: (1) to outline th…
Submarine canyon of the north-western Sicilian offshore (Southern Tyrrhenian Sea): variability in morphologies, sedimentary processes and tectonic se…
2013
Distinct microbial populations are tightly linked to the profile of dissolved iron in the methanic sediments of the Helgoland mud area, North Sea
2015
Iron reduction in subseafloor sulfate-depleted and methane-rich marine sediments is currently a subject of interest in subsurface geomicrobiology. While iron reduction and microorganisms involved have been well studied in marine surface sediments, little is known about microorganisms responsible for iron reduction in deep methanic sediments. Here, we used quantitative PCR-based 16S rRNA gene copy numbers and pyrosequencing-based relative abundances of bacteria and archaea to investigate covariance between distinct microbial populations and specific geochemical profiles in the top 5 m of sediment cores from the Helgoland mud area, North Sea. We found that gene copy numbers of bacteria and ar…
Tectono-sedimentary evolution of wedge-top basins in the north-western Sicilian Maghrebides (Italy)
2012
Hydrogeochemical multi-component approach to assess fluids upwelling and mixing in shallow carbonate-evaporitic aquifers (Contursi area, southern Ape…
2023
With the aim of deepening our understanding of deep-seated fluids upwelling and mixing in large regional aquifers, we performed a hydrogeochemical study of twenty-two springs in the Contursi area (upper Sele river valley, southern Apennines) by means of the measurements of chemical-physical parameters, major ions, trace elements, and stable and radioactive isotopes. Besides, we realized two updated geo-structural cross-sections in order to reconstruct the groundwater flowpath in the study area. The hydrogeochemical composition, as well as the water temperature allow to identify-three main groups of groundwater: Cold and Low salinity Groundwater (CLGW), Intermediate Salinity Groundwater (ISG…
Sand clams of Ganzirri marine coastal lagoon in Messina (Italy). Extraction and ICP-MS analysis
2008
This paper studies the possible forms or phases of heavy metals in sediments of a marine coastal lagoon, called Ganzirri, located in the Sicilian coast of the Messina’s strait by using sequential extraction. To reduce the extraction time of the Tessier method, the last step of speciation was carried out by mineralization in a microwave oven. Here we report the results of the distribution of As, Be, Cd, Co, Cr, Cu, Mo, Ni, Pb, Sb, Se, Tl, V and Zn, in four fractions of sediments samples and the concentration of the same metals in clams. This study looked at three bivalve mollusc species, Tapes decussates, Chamelea gallina and Cardium edule, raised in the sediment considered and discussed the…
El uso de imágenes Ikonos para la cartografía de riesgo de inundación en pequeñas cuencas mediterráneas
2006
La confección de una cartografía efectiva de riesgo de inundación precisa de la elaboración previa de mapas de peligro, que recojan las zonas sometidas a los procesos naturales asociados a la crecida. Para la configuración de estos mapas resulta muy útil el estudio de las áreas afectadas en sucesos concretos. En esta tarea el uso de la teledetección se ha demostrado altamente eficaz para el caso de grandes cuencas, afectadas por procesos de inundación extensivos y llanuras bien definidas. Sin embargo, para el caso de pequeñas cuencas mediterráneas, donde los espacios inundables son de índole muy variada, pequeña dimensión y rápido drenaje, el uso de las imágenes de satélite no siempre ha si…
Holocene sea level change in Malta
2013
A multidisciplinary approach has been applied to study sea level changes along the coast of Malta using data collected from underwater archaeological remains. The elevation of archaeological markers have been compared with predicted sea level curves providing new bodies of evidence that outline the vertical tectonic behaviour of this region, allowing estimation of the relative sea level changes that occurred in this area of the Mediterranean since the Bronze Age. During the Roman Age, sea level was at −1.36 ± 0.1 m, while in the Midde Age it was at −0.56 ± 0.2 m, in agreement with previous estimations for the Mediterranean region. Data indicate that Malta was tectonically stable during the …
Produzione di vini bianchi senza l’uso di solfiti
2014
Devona Sietiņu svītas nogulumu fācijas Latvijas ziemeļaustrumu daļā
2015
Šī pētījuma mērķis bija raksturot Sietiņu svītas nogulumu fācijas, to asociācijas un sniegt to veidošanās apstākļu interpretāciju Latvijas ziemeļaustrumu daļā. Pētījuma ietvaros sastādīti 4 ģeoloģiskie griezumi un nodalītas 11 fācijas ar apakšfācijām, kas grupētas 2 fāciju asociācijās. Korelējot griezumus ar urbumu datiem, noskaidrots, ka pētītie nogulumi atbilst Sietiņu svītas apakšējai līdz vidējai daļai. Secināts, ka pētītie Sietiņu svītas nogulumi veidojušies fluviālos kanālos zemūdens grēdās un progradējošās sērēs. Sedimentācijas procesus ir nedaudz ietekmējuši plūdmaiņu procesi, par ko liecina sporādiski sastopamas vizlas kārtiņas un drupu materiāla graudu izmēru gradācija uz slīpajie…