Stosunki izotopowe siarki w polskich złożach barytowych

Abstract

ISOTOPE RELATIONS OF SULPHUR IN POLISH BARYTE DEPOSITSSummarySulphur isotopes have been analysed in two large regions. In the Sudetes the isotope relations have been determined in barytes and paragenetic sulphides from the following deposits Stanisławów, Jedlinka and Boguszów, and in the Świętokrzyskie Mountains from the following points of mineralization: Hucisko, Góra Zachetna, Wiśniówka, Kozi Grzbiet and Strawczynek. The determinations have been made in relation to the pattern FeS2 of a meteorite from Spiro-Tunnel, in which the S32/S34 ratio has been determined as 22.22.The development of the conceptions concerning the course of the processes of sulphur isotope fractionation is discussed, and literature data on the baryte deposits in the world are shown in Tabs. 1, 2 and in Fig. 1.Heavy isotope S34 is found to occur in Polish baryte samples in an increased amount (Tab. 3, Fig. 12). Along with the barytes distinguished in the main deposit generations also hypergenic barytes have been examined. The latter ones were formed either during the process of sulphuretted hydrogen reduction (samples St-9, St-9a, B-48), or as a result of baryte weathering (sample B-60). Variability of isotope relations in barytes of main generations is low, and the enrichment in heavy isotope does not exceed +16,6‰. Sulphides, paragenetic with baryte (galena, sphalerite), show a slight enrichment in light isotope here. Pyrite, older than baryte (sample B-53), is enriched in heavy isotope, its genesis being related to the bitumens produced during the process of hard coal metamorphisation.It has been established on the basis of isotope, geological and petrographical examinations that the barites are of hydrothermal origin. Sulphur found to occur in barytes of Boguszów and Stanisławów was brought by sub-volcanic solutions separated in the process of differentiation of hybrid magma, whereas the solutions at Jedlinka came from the relict basaltic magma here. The baryte generations at Stanisławów, Jedlinka and Huciska reveal age differentiation (Fig. 3).The differences may be observed between the generations characterized by differentiated chemical nature of the solution (Stanisławów) or the separated tectonic phases (Jedlinka, Hucisko). A comparison of the results of isotope examinations of sulphur with the results of the absolute age determination in galena (Tab. 7, Fig. 4) from the Lower Silesian deposits proves this age differentiation. The examinations of galena and sulphur isotopes point to the Triassic-Jurassic age of the barytes from Stanisławów and Boguszów, and to the Tertiary age of the barites from Jedlinka.