“Lithological zoning and stable isotopes distribution in carbonates in the Polish native sulfur deposits. Implications for origin of the ores”. Discussion, comment

Abstract

The paper of A. Gąsiewicz and P. Olchowy on lithological zoning and stable isotopes distribution in carbonates in the Polish native sulfur deposits and implications for origin of the ores as a result of sedimentary processes, presented there, are discussed. Steep contacts of sulfur-bearing limestones with gypsum and barren limestones contradict their supposed sedimentary origin and zonation. The arguments in favour of replacement of gypsum by sulfur-bearing limestone are presented as well for formation of barren limestones by sulfur leaching and reprecipitation in the neighbouring sulfur-bearing and surrounding rocks. The registered lithologic zonation of sulfur deposits is not a result of aerial changes of sedimentary environment, but may be explained by pH and Eh variation of connate formation water. The well documented variation of δ13C and δ18O may be explained by weathering processes. Karstification of sulfur-bearing limestones produced the intercalations of clays with crumbled limestone and sulfur, resembling the synsedimentary breccia. There are no strong arguments in favour of sedimentary origin of sulfur ores. The formation of sulfur-bearing limestone in sedimentary environment, however, cannot be totally excluded, but if occurred, may take place on a very limited area, concurrently with formation through epigenetic gypsum replacement.