Fluid inclusions in celestine and their significance in the study of the formation of the native sulphur deposits in the Carpathian Foredeep

Celestine is a rather common mineral in epigenetic native sulphur deposits and seems to be a very valuable indicator of some of the geological processes forming these deposits. This paper presents the results of investigation of fluid inclusions in celestine from the Tarnobrzeg native sulphur deposits (SE Poland). Several different morphological types of celestine were selected from Machów open-pit mine. Study of the fluid inclusions has been carried out using microscopic and microthermometic methods. The data show that two types of chloride fluids were responsible for the formation of celestine and native sulphur and further transformation of the native sulphur deposits. The first type of fluid, containing a relatively higher salt content and lower NaCl/CaCl2 ratio, also points to the role of hydrocarbons during the formation of native sulphur deposits. The second type of fluid contains a relatively lower amount of salt and a higher NaCl/CaCl2 proportion and reflects the subsequent evolution of the chemistry of the fluids forming the deposits. The results of the study of fluid inclusions in celestine are in good agreement with its stable isotope composition.