Chlorophyll a and its derivatives in sediments of the Odra estuary as a measure of its eutrophication

Chlorophyll a and its selected derivatives, as well as chlorophylls b and c have been determined in samples of recent (0-10 cm) sediments, collected at 30 stations in the Szczecin Lagoon, Pomeranian Bay and the Bornholm Deep. Samples were retrieved in different seasons between 1992 and 2001, including the time before and after the great flood of July 1997. Regarding the content of chlorophyll a and its derivatives in sediments, the Szczecin Lagoon may be classified as permanently eutrophic and the Pomeranian Bay and Bornholm Deep as mesotrophic. A lack of correlation between chlorophylls b, c and chlorophyll a indicated that intensive blooms of cyanobacteria occur in the Szczecin Lagoon, which is a characteristic of eutrophic zones. The chlorin a results are related to selected parameters characterizing the aquatic environment. The values for nutrients, salinity and temperature in near-bottom waters, as well as granulometry and organic carbon in the sediments verify the above conclusions.     

Transfer of organic contaminants to the Baltic in the Odra Estuary

This paper describes the transfer of organic contaminants to the sea, using PAHs (12 compounds) and PCBs (11 congeners) as examples, through a eutrophicated coastal lagoon (Szczecin Lagoon, on the Polish-German border). The transfer of contaminants study was based on their concentration in recent sediments (0-10 cm), in relation to different environmental conditions such as temperature, salinity, turbidity, oxygen and nutrients in water, hydrological conditions, organic carbon and biomarkers (pigments and their derivatives) in sediments. Results include the data obtained between 1994 and 2000, also those on before and afterwards the great flood in July 1997, at different stations in the Lagoon and the adjacent Pomeranian Bay. The results indicated that the eutrophic estuary of the shape of lagoon acts as an effective trap for the hydrophobic organic pollutants. The abundance and taxonomy of plankton as well as detritus derived from it play an important role in bonding the studied compounds. The salinity gradient in the lagoon has a significant influence upon deposition of the pollutants from the water column to the sediments and the residence time of the compounds there depends strongly on oxic-anoxic status of the sediments and the strength of interaction with sediments resulting from polarity, the type and stability of associates formed, as well as on hydrological conditions. We conclude that eutrophication in this area prevents pollution of the sea to some extent.     

Tournaisian age of granitoids from the Odra Fault Zone (southwestern Poland): equivalent of the Mid-German Crystalline High?

The Odra Fault Zone of southwestern Poland is a NW-trending horst marked by gravimetric and magnetic anomalies and composed of high- to low-grade metamorphic and igneous rocks which are only known from boreholes. This zone embraces a concealed border between Variscan internides and externides. It also contains an array of several I-type, metaluminous to peraluminous, high potassic granitoid bodies which intruded earlier metamorphosed rocks. Except for one case, they remain unfoliated and undeformed, and presumably play a role of stitching plutons at the suture between two obliquely colliding terranes. U–Pb TIMS dating of single zircons from one foliated and one unfoliated granitoid samples yielded identical concordant ages of 344±1 Ma (Tournaisian). They resemble a Pb–Pb age of 350±5 Ma obtained for S-type granitoids from the Luckau area further west in Germany, which is generally regarded as an eastern segment of the Mid-German Crystalline High. Carboniferous granitic intrusions in the high are generally younger (340–290 Ma). Correlations of the the Odra Fault Zone with the Mid-German Crystalline High appear plausible, but by no means certain and require further confirmation.     

3D GPR measurements for archaeological application with interpretation aided by numerical modelling

The paper presents the results of georadar investigations carried out in the area of the monastery at Tyniec near Cracow for archaeological purposes. The georadar profiles were designed on the abbey courtyard in a regular grid, which covered the area of the buildings that currently do not exist. The aim of the measurements was to produce a 3D visualization of former buildings’ foundation. The results of the geophysical measurements were correlated with the information obtained from archaeological investigations. The georadar surveys confirmed the location of foundations documented by archeologists and new underground structures were discovered. To aid the interpretation, numerical modelling of the electromagnetic wave field was performed. Computer modelling allowed to determine the kind and condition of underground structures.     

Distribution and morphometric characteristics of icing fields in Svalbard

Icing fields are common in Svalbard and very diverse with respect to shape. The occurrence and spatial structure of icing fields in front of glaciers were analysed using aerial photographs (at a scale of 1:50000) taken from 19 July to 25 August 1990–a unique set of images covering the whole archipelago in one summer season. Icing fields were observed in front of 217 glaciers. A total area of 12.3 km² appeared to be covered by the icings. This value, from late in the ablation season, is likely to be near the seasonal minimum. Of the 217 glaciers, 192 were selected for further analysis, carried out by stereoscopic observation of the aerial photographs. Striking difference in brightness of the icing fields in comparison to the surrounded terrain combined with field experience of the geomorphic setting of its occurrence made possible the complete inventory of the icing phenomena for the whole of Svalbard. Morphometric features were measured directly on photographs and on scanned portions of them. Results from field studies of melting and the decrease of the area of icing fields at the front of two glaciers are also presented. The shape and distribution of icings depend on a set of glaciological factors and on the glacial and geomorphologic setting. The duration of frigid temperatures in the winter when the icing fields were formed is also important. Results show that oval and circular shapes are characteristic for icing fields after surviving the ablation season. These fields have an important geomorphological influence on the outwash plains that currently develop in Svalbard.     

Alkali feldspar megacryst growth: Geochemical modelling

Summary Alkali feldspar megacrysts from the porphyritic Karkonosze granite (Western Sudetes, Poland) were formed during magma mixing. Barium concentrations in zoned crystals, a sensitive indicator of feldspar migration between coeval magmas, serve to reconstruct the crystallization path of the megacrysts. Based on geochemical data, a double mixing model for the formation of the porphyritic granite and for megacryst growth is constructed. The feldspar growth model supports megacryst nucleation and early crystallization in a hybridized crustal magma of granodioritic composition. The growth model gives credibility of the choice of partition coefficients used in the modelling. Insights gained from mixing models based on whole rock composition and mineral zonation allow the recognition of various hybridization events that are reflected in a variety of megacryst crystallization paths within the pluton.     

The atmospheric distribution of lead over a number of marine regions

A data base of 111 filter-collected marine atmospheric particulates is used to describe the distribution of lead over the North and South Atlantic, the Mediterranean Sea, the Red Sea, the Gulf of Aden and the northern and central Arabian Sea. The distribution of atmospheric Pb is assessed in terms of enrichment factor diagrams, and it is shown that over the marine regions studied in both the Northern and Southern Hemispheres the distribution of Pb in the atmosphere is controlled by the mixing of a background component, or components, with crustal material within certain concentration limits. For the Northern Hemisphere samples used in the investigation there is a reasonably well-defined Pb concentration minimum of ～ 0.6 ng m^?3 of air; however, this will be severely decreased in more remote Northern Hemisphere marine regions. Geometric average Pb atmospheric concentrations vary from one marine region to another, ranging from ～ 0.98 ng m^?3 of air for the South Atlantic westerlies to ～ 15 ng m^?3 of air in the North Atlantic westerlies; although the latter reduces to ～ 7 ng m^?3 of air when ‘polluted’ samples are excluded. Lead sea-surface deposition fluxes are calculated on the basis of two deposition velocities (0.25 and 1 cm s^?1), the largest flux (220 ng Pb cm^?2 yr^?1) being found for the westerlies over the eastern margins of the North Atlantic. The distribution of lead over the North Atlantic is assessed in terms of the global lead budget and it is estimated that a maximum of ～ 24% of the total ‘natural’ lead injected annually into the World atmosphere, and ～ 3.5% of the anthropogenic lead injected annually into the Northern Hemisphere atmosphere, are deposited over the North Atlantic sea surface.