1,720,965 research outputs found
Geochemistry of recent sediments in the Lagoon of Venice.
No full textGeochemical researches have been carried out on bottom sediments subdivided in two levels (0-2 cm; 3-10 cm). The top sediments differ from deeper ones for some significant elements, such as Al, K, Fe, Mg and P, Zn, Pb, Cd. To evaluate the anthropogenic contribution, the heavy metals contents detected in two levels were discussed. -from Author
Spatial and temporal evolution of heavy metals accumulation in sediments of the Lagoon of Venice: environmetal implications
No full textProcessi di accumulo dei metalli pesanti nei sedimenti, fattori ambientali ed influenza antropica. il caso della Laguna di Venezia.
No full textSedimentological variability and bathymetric changes of the Lagoon of Venice in the last 30 years.
No full textGeochemistry of natural and anthropogenic fall-out (aerosol and precipitation) collected in NW Mediterranean: two different multivariate statistical approaches
Full text linkThe chemical characteristics of the mineral fractions of aerosol and precipitation collected in Sardinia (NW Mediterranean) are highlighted by means of two multivariate statistical approaches. Two different combinations of classification and statistical methods for geochemical data are presented. It is shown that the application of cluster analysis subsequent to Q-Factor analysis better distinguishes among Saharan dust, Background pollution (Europe-Mediterranean) and Local aerosol from various source regions (Sardinia). Conversely, the application of simple cluster analysis was able to distinguish only between aerosols and precipitation particles, without assigning the sources (local or distant) to the aerosol. This method also highlighted the fact that crust-enriched precipitation is similar to desert-derived aerosol.
Major elements (Al, Na) and trace metal (Pb) turn out to be the most discriminating elements of the analysed data set.
Independent use of mineralogical, granulometric and meteorological data confirmed the results derived from the statistical methods employed
Sediment properties and their influence on the geochemical composition in the Lagoon of Venice.
No full textThe grain-size distribution, mineralogical composition, heavy mineral assemblages, surface area and concentration of major and trace elements have been determined for bottom sediments from a restricted zone of the Lagoon of Venice, which is of environmental concern. The interpretation of various parameters and their inter-relationships has been done using several statistical procedures. The most common sediments are day silts, typical of a low energy environment. Their fine grain-size favours the uptake of trace elements. Three mineralogical assemblages with specific areal distributions have been identified, both from the provenance of detrital materials and from the depositional conditions. The predominance of semistable and unstable heavy minerals was observed. Some heavy minerals were also recognized as tracers of the rivers reaching the lagoon in the past. The surface area appears to be related to the presence of fine particles and/or clay minerals. The abundance of major elements reflects the mineralogical composition. The trace element distribution shows two zones with different contamination, referable to industrial and municipal discharges. The relationships between heavy metals concentrations and sediment properties are variable. The main role was played in some cases by the fine grain-size and surface area, and in other cases by day minerals
Major element geochemistry of sediments from the Ross Sea, Antarctica
No full textIndicates the silicate composition of the examined sediments. The different concentrations of the major elements, their geographical distribution and inter-relations allowed the distinction of three populations of samples with specific geochemical characteristics and locations. -from Author
Geochemistry of natural and anthropogenic aerosols and precipitations collected at remote site in the Mediterranean: a combination of factor, cluster and discriminant analyses.
No full textEvidence of sedimentological changes on decadal scale in the national interest site of the Lagoon of Venice due to anthropogenic factors
No full textContributions of the geochemistry, petrology and sedimentation processes to the environmental research. Three cases of study: estuarine, lagoonal, and marine environment
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