Distribution of strontium in the Badenian (Middle Miocene) gypsum deposits of the Nida area, southern Poland

Abstract

A succession of different lithofacies including fifteen units, from a to n, have been distinguished in the gypsum section of the Nida area. Geochemical data show distinct variation of the Sr content in gypsum, between 0.03 and 3.13% (average 0.30% Sr). In gypsum lithofacies, a high Sr concentration averaging 0.5% was found in selenitic gypsum and in gypsorudites. The vertical distribution of strontium throughout the section is not uniform. The average strontium content increases in the middle section and reaches as much as 0.92% Sr in unit h. South of the Holy Cross Mts. the horizontal distribution of strontium in gypsum and coeval carbonates is characterized by higher concentration in the northernmost part of the area (Staszów region). Variability of the strontium content throughout the cyclic sequences reflects the evolution of brines during the gypsum formation. The results suggest important diagenesis of the gypsum deposits which allowed the migration of strontium and subsequent crystallization of celestite.