Mineralogy, geochemistry, and stable isotope characteristics of Paleozoic carbonate-hosted vein-type barite deposits from Silifke–Mersin, Southern Türkiye

Abstract

The Taurus Belt, one of the main tectonic belts of Türkiye, is represented by Paleozoic-aged carbonate rocks. Cilbayir and Gokbelen (Silifke/Mersin) barite deposits located in these rocks were subjected to a detailed investigation to determine their geochemistry, stable isotopic composition, mineralogy, and genetic model. The ore zone contains the veins and lenses necessary for barite, calcite, and hematite paragenesis. A barite vein strikes N35°E and dips 15°NW in the fragments of the limestone-shale sequence in the north of Gokbelen. Another ore zone has been located in the north and northwest of Cilbayir, and it is associated with limestones along a fault line striking N30°E. The veins containing barite, calcite, and hematite paragenesis have approximately the same BaO content (Cilbayir, 65.05%; Gokbelen, 64.96%). The rare earth element (REE) composition of barites is extremely poor (ƩREE is less than 10 ppm), while ƩREE in carbonate host rocks ranges between 40 and 45 ppm. The mean δ³⁴S values of Gokbelen and Cilbayir are 36.45‰ and 41.87‰, respectively. The average imports of δ¹⁸O_SMOW barites were 12.98 ‰. The Gokbelen barites have an ⁸⁷Sr/⁸⁶Sr ratio of 0.718796, while the Cilbayir barites have a ratio of 0.717845. Mineralization at Cilbayir is consistent with vein type with a mean SrO content of 1.2%. In contrast, samples from the Gokbelen area show characteristics of hydrothermal vein-type formations with significant SrO content (average 1.47%). The integration of mineralogical, geochemical, and stable isotope data allows for a comprehensive interpretation of the origin and evolution of the carbonate-hosted vein-type barite deposits in the Silifke–Mersin region.