Problem powstania tarnobrzeskiego złoża siarki rodzimej w świetle badań petrograficznych

Abstract

Badania mineralogiczne ujawniły znaczącą rolę magnezu i manganu w procesach metasomatycznych przeobrażeń siarczanów w węglany. O antagonistycznym zróżnicowaniu tych pierwiastków decydowała przypuszczalnie substancja organiczna. Stwierdzono dwa rodzaje szczątków pobakteryjnych: starsze i młodsze, którym prawdopodobnie można przypisać odpowiednio funkcje redukowania gipsu do siarkowodoru, a następnie jego utleniania do siarki rodzimej.

THE QUESTION OF ORIGIN OF THE TARNOBRZEG NATIVE SULFUR DEPOSIT IN THE LIGHT OF PETROGRAPHIC STUDIES

The studies on minerals from the Tarnobrzeg native sulfur deposit gave new data on morphology of carbonates, sulfates and sulfur, and chemical composition, especially distribution of such elements as Mg, Mn, Bi, Cd, and K. The role of magnesium and manganese in metasomatic transformations was found to be significant. These elements are concentrated at boundaries of calcite and celestine or anhydrite and celestine and anhydrite which may evidence influence of organic life on metasomatic transformations. The behaviour of magnesium and manganese is antagonistic and the elements concentrate at opposite sides of a grain: the former usually in superseded mineral, and the latter in the superseding one.

Relics of bacteria were found in post-gypsum limestones and native sulfur. The bacteria possibly differed in specialization. They may be divided into older and younger and, arbitrarily, those reducing sulfides to H₂S and the others, oxidating H₂S to sulfur. The older bacteria are up to 1.5 mm in size (usually 1.2-0.8 mm in size), strongly mechanically deformed and overgrown with calcite dust and clay minerals. The younger bacteria, more common than the older, are usually spherical, up to 0.4 mm in size (usually 0.3-0.2 mm in size), and characterized by well preserved cytoplasmatic bridges.

Cross-sections of remains of bacteria are extremely scarce. They usually display calcitic tests with outer part somewhat enriched in magnesium and the inner infilled with sulfur. The post-bacterial forms are most often represented by sulfur granules only.

Fine granular concentrations of sulfur often cover remains of algae and other organic forms. The arrangement of these forms is random. Therefore, attention should be paid to some occurrences of string- like arranged dusty sulfur granules 0.025-0.15 mm in size. The latter may evidence original concentration of sulfur in cell plasma of thread-like oxidating bacteria such as Beggiatoa alba or Thiotrix nivea.