FORMATION OF SULFIDE MINERALIZATION AS A RESULT OF DECOMPOSITION OF BLACK SHALE BY GROUND WATER IN TECTONIC DISLOCATION ZONES

Abstract

For the Baltic shale basin, we consider an example in which decomposition of caustobioliths (combustible shales), accompanied by generation of sulfide sulfur, predetermined the formation of sulfide mineralization. This cycle was caused by the influx into the respective stratigraphic intervals of sulfate sulfur, which, in turn, was a decomposition product of earlier formed sulfides and sulfates in overlaying horizons. These phenomena occurred separately in space and time and were localized on hypsometrically different levels of tectonic dislocations. The results show that in tectonic dislocations in fault zones, the caustobiolithic function of organic matter in black shale is superseded by an ore-generating one. As far as the form of mineral resources is concerned, the role of these zones is ambiguous, i.e., destructive for caustobioliths, but creative for sulfide mineralization. The extent of fracturing in fault zones themselves and their volume in these intervals are greater. Such multi-plane phenomena result from the generation of sulfide sulfur in black shale.