Badania geochemiczne utworów menilitowych w Karpatach środkowych

Abstract

GEOCHEMICAL RESEARCHES OF MENILLITE FORMATIONS IN THE MIDDLE CARPATHIANS

Summary

The paper contains chemical and geochemical characteristics of the menillite formations that occur in the Middle Carpathians. Chemical analyses of the menillite formations allow to distinguish here non-carbonate clay shales, carbonate clay shales, marls, as well as flinty limestones and shales. These deposits particularly, however, the non-carbonate clay shales are rich in shale oil (maximum contents 9,5%). An increased concentration of vanadium and of molybdenum in the deposits characterized by a high content of bitumens prove that the metals have been accumulated here biochemically. This conclusion is supported by relatively high concentrations of both elements in clay shale ash (4557 ppm V and 2500 ppm  Mo), and by the diagram of dependence of V and Mo upon shale oil content (Figs. 2 and 3). Analyses of various horizons, that occur in weathered zone and in deeper parts not invaded by weathering processes, permit observe that vanadium combinations are stable here (greater concentrations of vanadium in jarosite have not been ascertained). Similar stable metallo-organic combinations are characteristic of molybdenum, although small amounts of this chemical element; accumulated biochemically, also make sulphide combinations. These are, however, less stable (quantity of Mo in jarosite is 57 ppm), and may pass into weathering minerals. The other metals determined in the deposits considered (Cr, Ni) do not occur in great quantities there.