Кравчук Г. О.

The work is devoted to application of the benthic foraminifera for an evaluation of an geoecological situa-tion on a northwest shelf of the Black Sea. The awake role of organisms with carbonaceous function is marked during biological absorption of toxic bonds. The attributes of stressful situations on population and organismic level include a degree of a surviving of species and morphological changes of the foraminifera. These parameters applied for abjection of geographic ranges of a toxic stimulation, development and anomalous morphology of organisms. Purpose. The aim of this work is to analyze the effect of significant cadmium content on benthic foraminifers of the Black Sea shelf (Danube Delta region). Methods. Field studies provided for the selection, documentation and preparation of analytical samples. Micro-paleontological and lithologic-geochemical studies of bottom sediments were carried out in accordance with accepted methods. The method for studying foraminifera includes the following operations: sampling, separation, preservation and preparation for analysis, taxonomic identification, morphological analysis, biomineralogical studies and mathematical processing of results. Results. The conducted observations confirm the possibility of differentiated assessment of heavy metal contamination by the example of cadmium in the shelf Black Sea. Areas of pollution are characterized by a decrease in the species diversity of foraminifera compared to uncontaminated areas. In sediments with a high content of cadmium, foraminifera are characterized by depressed forms with numerous deformities. Conclusions. A significant concentration of cadmium strongly affects the occurrence of foraminifera and the appearance of morphological anomalies in their shells.

There are devoted to application of the mineralogical function of the foraminifera to assess the geoecological situation. Analyzed rentgenometric characteristics of the mineral structure of benthic foraminifera shelf of the Black Sea. Revealed that the abnormal development of biomineralization is accompanied by morphological changes and are clearly seen in the structure of the walls of the shells of foraminifera.

This work is analysed of conditions of a sedimentation has shown, that their changes are connected to increase of an outlet of biogenic matters and transferring from eutrophic to hypertrophic phase of development of basin at last decades. The geochemical consequences of pollution on a shelf are shown in summer activization of reduction conditions, decrease pH of deposits, presence of aboriginal hydrogen sulphide.

Considers modern geochemical characteristics of migration processes in pollution northwestern Black Sea shelf. Bulk precipitation suspension occurs on geochemical barriers "river-sea" or on the shelf outside the aver-age wave field. The main factor limiting the migration of solutes are the processes of biological absorption.Using cluster analysis, multidimensional establish substantial divergence component ratios depending on the time of observation. On the example of cadmium tendency to accumulate the most mobile of toxic components in the carbonate sediments of the shelf.