Badania geochemiczne metamorfiku białowieskiego

Abstract

GEOCHEMICAL RESEARCHES OF THE BIAŁOWIEŻA METAMORPHIC ROCKS

Summary

Some trace elements that occur in the metamorphic rocks of the Białowieża region were investigated and discussed. The purpose of the investigation was to determine the assemblage of chemical elements and the concentration of these elements in the individual rock types, as well as to define the character of the relation existing between the trace elements and the chemical and mineral composition of rocks. As a results of the studies, Ni, Co, V, Cr, Mn, Pb, Sn, Cu, Zn, Ga, Mo and Ag contents were determined, and the behaviour of these chemical elements was ascertained in relation to Ti, Fe and Mg. It was also ascertained that the analysed assemblage of trace elements occurs, except for Mo, Ag and Sn, in all the rock types examined. The highest concentrations of the chemical elements of iron family (Ti, Ni,. Co, V, Cr and Mn) are related to the amphibolites from Waśki, characterized by gabbro texture. Gneisses, in turn, are distinguished by a considerable change in concentration of the chemical elements mentioned above. The change is closely connected with their varying mineral composition. In all the rocks of the Białowieża region, cobalt does not show any essential differentiation and occurs from 10 to 30 ppm. Among the chemical elements here determined, both nickel and chromium show the greatest change in concentration. In the amphibolites of the Białowieża series, chromium occurs from 5 to 2000 ppm; nickel also ranges widely, its content amounting to 15–330 ppm. It has also been ascertained that the amphibolites of the Białowieża series occur in two genetically different types. The average concentrations of the chemical elements here analysed were calculated and summed up, and the relations and correlations between the chemical elements of the metamorphic series were determined. Furthermore, a statistical analysis of Ni, Co, V, Cr and Mn frequency in the rocks of the Białowieża series was made. The results of the examinations allowed the present author to obtain parameters useful in comparing the metamorphic assemblages of various series of the Podlasie metamorphic complex.