Dolomitization of Late Norian carbonate deposits of restricted basin facies in the Keszthely Mts., Transdanubian Range, Hungary

Abstract In the Transdanubian Range (Hungary), a wide spectrum of Triassic dolomites is known. Mechanism dolomitization platform carbonate successions was subject number studies but study basinal carbonates very limited. Petrographical and isotope–geochemical characteristics Upper dolomitized deposits, formed in fault-controlled intraplatform basin, interpretation dolomite-forming processes are presented current paper. From latest Carnian to Middle Norian under semi-arid climatic conditions density-driven flux seawater derived mesohaline fluids dominant mechanism near-surface pervasive thick succession. late incipient rifting Alpine Tethys led establishment an extensional structural regime onset formation Kössen Basin. area, above succession, platform-derived sediments were accumulated fault-bounded, semi-restricted sub-basin Basin, whereas talus breccias debrites deposited near basin-bounding master fault. The basin deposits (lower upper members Rezi Dolomite Formation) early diagenetic shallow burial setting. Enhanced salinity dolomitizing fluid; synsedimentary fracturing may have promoted fluid flow thereby dolomitization. Thick-bedded (middle member representing progradational tongue ambient intercalated between deposits. this unit can be explained by reflux model.