Trace- and rare-earth element geochemistry of the Karalar (Gazipasa-Antalya) Barite-Galena deposits, southern Turkey

Abstract

The Karalar barite-galena deposits are typical examples of carbonate-hosted barite-galena deposits that occur widely in the central Taurides. Recent mining activity has been concentrated in the Buyuk and Boyalik mine areas. The mineralisation occurs as ore veins along fault zones and as ore-filled breccia zones along the strongly deformed lower walls of limestone blocks in the Permian limestones of the Bickici Formation. These veins contain mainly barite (80-85%) and galena (10-15%), and lesser amounts of sphalerite, pyrite, fahlore, limonite, quartz and calcite as gangue minerals. Barite developed during an early episode of mineralisation and was mylonitised before the precipitation of other minerals. Trace-element geochemical studies show that Ba and Pb may have been derived from different sources: Ba is enriched in mudstones of the Ordovician Cakmak Formation, and Pb is enriched in limestones of the Permian Bickici Formation. The trends of the REEs-Y profiles and the plots of the values of barites and galenas on the Ce-N/Sm-N versus Ce-N/Yb-N diagram indicate that a seawater-dominated hydrothermal fluid supplied the barium and sulfate ions and deposited the barite, while a fluid mixture of seawater and a Tibetan-type (terrestrial) hydrothermal fluid was responsible for galena deposition. There is also a genetic relationship between galena and Permian limestone and dolomitisation processes.