Distribution Of Elements In Sediments Research Articles

Biogenic components and trace elements in the sediments of river mouths and accumulation areas of the Curonian Lagoon (south-eastern Baltic Sea)

The main suppliers of sedimentary matter into the large coastal freshwater lagoon of the southeastern Baltic (Curonian Lagoon) are the Neman River including the sleeves Atmata, Skirvytė and Razliv, as well as Matrosovka and Deima rivers. Large catchment area of the rivers densely populated and characterized by intensive industrial and agricultural activities, which are regarded as potential suppliers of biogenic and chemical elements. Elevated amounts of biogenic components (nitrogen and phosphorus) as well as arsenic recorded in sediments from the river mouth areas suggest serious contribution of anthropogenic activities (use of fertilizers and pesticides in the agricultural activities) on the general sediment quality in the investigated area. Newly obtained data clarify the patterns of biogenic and trace element distribution in sediments located in close vicinity of potential pollution sources.

Sedimentology and geochemistry of mud volcanoes in the Anaximander Mountain Region from the Eastern Mediterranean Sea

Investigations carried out on surface sediments collected from the Anaximander mud volcanoes in the Eastern Mediterranean Sea to determine sedimentary and geochemical properties. The sediment grain size distribution and geochemical contents were determined by grain size analysis, organic carbon, carbonate contents and element analysis. The results of element contents were compared to background levels of Earth’s crust. The factors that affect element distribution in sediments were calculated by the nine push core samples taken from the surface of mud volcanoes by the E/V Nautilus. The grain size of the samples varies from sand to sandy silt. Enrichment and Contamination factor analysis showed that these analyses can also be used to evaluate of deep sea environmental and source parameters. It is concluded that the biological and cold seep effects are the main drivers of surface sediment characteristics from the Anaximander mud volcanoes.

Distribution of trace elements in stream sediments of Arta plain (western Hellas): The influence of geomorphological parameters

Stream sediment samples were collected from Arachthos River, Arachthos–Vovos Artificial Channels, Louros Artificial Channels, Louros River and Vovos River, which are located in Arta plain (western Hellas). The samples were taken in order to determine the spatial distribution of selected elements (Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sr, V and Zn), and to evaluate the geogenic and anthropogenic factors controlling the distribution of elements in sediments. The methodology applied in this study includes geomorphological analysis, chemical analysis, factor analysis and comparison of element contents with other data sets. The weathering materials, derived from the Arachthos River's drainage basin, contribute the high element contents in the sediments of the Arta plain. The high element contents may be related with the very gentle slope of the area and the long length of artificial channels. Interpretation of factor analysis results points to geogenic (Fe-oxides, calcareous rocks with phosphorite intercalations, ophiolite fragments within deltaic deposits) and possibly anthropogenic contamination sources (intensive agricultural and farming practices), which control the element distribution in the stream sediments.

Mercury in Some Lakes of Gold Mining Area of the Southern Ural

The mercury content in bottom sediments of Kalkan Lake, of the Uchala district, the Southern Ural. It was assumed that high concentrations of mercury in fish due to pollution of bottom sediments as a result of amalgamation at developing of gold placers. Detailed study of distribution of different elements in sediments show close association Hg with the chalcophylic elements, whose anomalies do not have technogenic nature. Association of mercury with the elements-companions of gold placers is evidence of basic contribution of natural mercury to its anomalous accumulation in sediments and fish. This is result of steady long-term natural mercury pollution.

Historical trace element distribution in sediments from the Mississippi River delta

Five sediment cores were collected on the shelf of the inner Mississippi Bight in June 2003 for a suite of radionuclides to establish geochronologies and trace elements to examine patterns of contaminant deposition and accumulation. Core sites were chosen to reflect a matrix of variable water depths, proximity to the Mississippi River mouth as the primary source for terrigenous particles, and extent and duration of summertime water column hypoxia. The vertical distribution of239,240Pu and210Pbxs(=210Pbtotal−226Ra) provided reliable geochronological age constraints to develop models for mass accumulation rates and historic trace element inputs and variations. Mass accumulation rates ranged from 0.27 to 0.87 g cm−2yr−1 and were internally consistent using either210Pbxs or239,240Pu. Measured inventories of137Cs,239,240Pu, and210Pbxs were compared to atmospheric deposition rates to quantify potential sediment focusing or winnowing. Observed variability in calculated mass accumulation rates may be attributed foremost to site-specific proximity to the river mouth (i.e., sediment source), variability in water depth, and enhanced sediment focusing at the Mississippi River canyon site. Trace element concentrations were first normalized to Al, and then Al-normalized enrichment factors (ANEF) were calculated based on preanthropogenic and crustal trace element abundances. These ANEFs were typically >1 for V and Ba, while for most other elements studied, either no enrichment or depletion was observed. The enrichment of Ba may be related, in part, to the seasonal occurrence of oxygen-depleted subsurface waters off the Mississippi River delta, as well as being an ubiquitous byproduct of the petroleum industry.

Heavy metals and arsenic in sediments, mussels and marine water from Murano (Venice, Italy)

This paper describes a study of the trace element distribution in sediments, marine water and mussel Mytilus galloprovincialis of the Venetian Lagoon around the Island of Murano, an island with a long tradition of glassmaking. Trace elements analysed include Fe, Mn, Zn, Cu, Cr, Pb, Ni, Ag and As. Sediments are contaminated with Zn, Cu, Ag, As and Pb, with levels in the <2 m fraction that are likely to cause adverse biological effects to marine organisms. The pelite (<63 μm) is the main carrier of heavy metals at most sites. However, the fine-grained and coarse sand on the southern coast of Murano accounts for a significant proportion of Fe, Mn, Zn, Cr, Ag, Ni and Pb. Most trace element concentrations found in soft tissue of mussels appear to be within recommended Italian and international guidelines for shellfish for human consumption, the only exception being relatively high As levels. The bioaccumulation of Ag and Cr is more pronounced in the shell of these organisms. In the marine water of the lagoon, trace elements are more enriched than in other areas of the Mediterranean, with particular reference to the dissolved labile species of Zn, Mn, As, Cu, Ni and Cr.

Geochemical signals of orbital forcing in the records of paleoclimates found in the sediments of Lake Baikal

X-ray fluorescent analysis with synchrotron radiation (SRXFA) and neutron activation analysis (NAA) were used to study the distribution of elements in sediments of Lake Baikal over the time interval of Brunhes Epoch (0–780 kyr BP). The concentrations of some elements and their ratio respond to changes of the climate. Sr/Ba, Sr/Rb, Sr/Cs, Sr/Fe, Sr/Ti, U/Th, Zn/Nb, Mo, Eu, Y, Yb positively correlate with the content of biogenic silica (BiSi) which is high at intervals belonging to interglacials and small at those belonging to glacials. On the contrary Ba, Rb, Cs, Th, La, Ce, Nd, La (Ce)/Yb (Y, Zr) negatively correlate with BiSi. These two series of geochemical signals, along with BiSi, reflect oscillations of the climate between glacials and interglacials. Spectral analysis of the records revealed that they are modulated by orbital forcing. This proves that the climates of East Siberia depend on orbital forcing to the similar extent, as does the global climate. Comparison of the climate records found in the sediments of Lake Baikal with the pattern of orbital parameters made it possible to estimate the mean rates of sediment accumulation over different time intervals and to refine the age–depth model.

Rare earth element distribution in sediments from the Minho river and estuary (Portugal) — a preliminary study

Rare earth element distribution in sediments from the Minho river and estuary (Portugal) — a preliminary study

A geochemical profile in the Baltic Sea

An investigation has been made of the relationship between depositional environment and element distribution in sediments from the Baltic Sea. A prominent feature of the Baltic is its salinity stratification, which gives rise to changes in bottom character from oxygenation to stagnation as greater depths are approached. Maximum heavy metal concentrations were not found in the contral, most stagnant and organic-rich parts of the basins, but in the transition zone to stagnant conditions. Manganese-iron nodules were found in a peripheral area characterized by aerated bottom water but moderately reducing sediment environment, as measured by redox potential determinations. In two of the Baltic deeps manganese was found enriched in sapropelic sediments, in one case reaching 5.2 per cent MnO. The mineral responsible for the enrichment is regarded as a mixed manganese-calcium carbonate.