Trace elements in the aerosol at Neumayer Station, Antarctica

Atmospheric trace element concentrations were measured from March 1999 through December 2003 at the Air Chemistry Observatory of the German Antarctic station Neumayer by inductively coupled plasma - quadrupol mass spectrometry (ICP-QMS) and ion chromatogra-phy (IC). This continuous five year long record derived from weekly aerosol sampling re-vealed a distinct seasonal summer maximum for elements linked with mineral dust entry (Al, La, Ce, Nd) and a winter maximum for the mostly sea salt derived elements Li, Na, K, Mg, Ca, and Sr. The relative seasonal amplitude was around 1.7 and 1.4 for mineral dust (La) and sea salt aerosol (Na), respectively. On average a significant deviation regarding mean ocean water composition was apparent for Li, Mg, and Sr which could hardly be explained by mir-abilite precipitation on freshly formed sea ice. In addition we observed all over the year a not clarified high variability of element ratios Li/Na, K/Na, Mg/Na, Ca/Na, and Sr/Na. We found an intriguing co-variation of Se concentrations with biogenic sulfur aerosols (methane sul-fonate and non-sea salt sulfate), indicating a dominant marine biogenic source for this element linked with the marine biogenic sulfur source.

Dissolved chemical elements in river waters of the Wrangel Island

Pioneer information about chemical composition of river waters in the Wrangel Island has been obtained. It is shown that water composition reflects the lithogeochemical specifics of primary rocks and ore mineralization. In contrast to many areas of the Russian Far North river waters of the island are characterized by elevated background value of total mineralization (i.e., total dissolved solids, TDS) (0.3-2 g/l) and specific chemical type (SO4-Ca-Mg). This is related to abundance of Late Carboniferous gypsiferous and dolomitic sequences in the mountainous area of the island. It has also been established that salt composition of some streams is appreciably governed by supergene alterations of sulfide mineralization associated with quartz-carbonate vein systems. They make up natural centers of surface water contamination. Waters in such streams are characterized by low pH values (2.4-5.5), high TDS (up to 6-23 g/l) and SO4-Mg composition. These waters are also marked by anomalously high concentrations of heavy and non-ferrous metals, as well as REE, U, and Th.

Lignin, phenols, and some chemical elements in aerosols and bottom sediments from the Tropical North Atlantic

A study of composition of biomarkers (lignin and phenols) in aerosols and bottom sediments from the Tropical North Atlantic was carried out. It was shown that organic matter of aerosols was mostly composed of products of terrestrial plants (arboreal fibers, pollen, and spores). Biomarker composition in the aerosols and in the bottom sediments was practically similar, which proved delivery of terrigenous organic matter to the ocean via the atmosphere.

Chemical composition and accumulation rates of chemical elements in metalliferous sediments from axial zones of the East Pacific Rise and the Mid-Atlantic Ridge

In the monograph metalliferous sediments of the East Pacific Rise near 21°S are under consideration. Distribution trends of chemical, mineral and grain size compositions of metalliferous sediments accumulated near the axis of this ultrafast spreading segment of the EPR are shown. On the basis of lithological and geochemical investigations spatial and temporal variations of hydrothermal activity are estimated. Migration rates of hydrothermal fields along the spreading axis are calculated. The model of cyclic hydrothermal process is suggested as a result of tectono-magmatic development of the spreding centre.

Rare earth elements in bottom sediments from the deeps of the Red Sea rift zone

Analysis of rare earth element (REE) distribution and behavior in ore-bearing hydrothermal-sedimentary deposits from the Red Sea is carried out. Geochemical patterns and mechanisms of REE accumulation in metalliferous sediments of the open ocean and in deposits adjoined to areas of hydrothermal discharge are shown. Main factors, which determine composition of REE and the level of their accumulation in hydrothermal occurrences of the Red Sea, are considered.

Contents and accumulation rates of the rare earth and some other elements in metalliferous sediments from DSDP Hole 92-598

The sediments recovered during DSDP Leg 92 (Site 598) include a complete 16 m.y. record of hydrothermal sedimentation along the western flank of the East Pacific Rise at 19°S. Fifty samples from this sediment column were analyzed to test the hypothesis that the REE composition of the hydrothermal component is primarily acquired via scavenging from seawater. Site 598 provides an ideal sample suite for this purpose: the sediments are lithologically "simple," primarily consisting of a mixture of hydrothermal materials and biogenous carbonates; the composition of the hydrothermal component is essentially constant through space and time; and the sediments have undergone minimal diagenetic alteration. The following observations suggest the above-stated hypothesis is true. The Ce anomaly as well as key indices of light and heavy REE behavior all show that the REE pattern of hydrothermal sediments approaches that of seawater with increasing paleodistance from the rise crest. Moreover, shale-normalized REE patterns are similar to that of seawater, varying only in absolute REE content: the REE content increases with distance from the paleo-rise crest and exhibits a pronounced increase in sediments deposited below the paleolysocline. Based on significant correlative relationships between paleodistance from the rise crest and both the concentration and mass accumulation rates (MARs) of REEs and Fe, we conclude the REEs in the hydrothermal component are derived from the interaction of seawater and Fe in the hydrothermal plume.