Relationship between dolomite textures and formation temperature - Insights from the Riópar area (Betic Basin, SE Spain)

This study reports textures and homogenization temperatures of primary fluid inclusions on dolomites hosted in Upper Jurassic to Lower Cretaceous age carbonate sequence from the Riópar area (Mesozoic Prebetic Basin, SE Spain). Five dolomite texture-types have been identified: i) planar subhedral replacive dolomite (ReD); ii) transition between planar subhedral to euhedral dolomite (ReD-SuD); iii) planar euhedral sucrosic dolomite (SuD); iv) non-planar cloudy saddle dolomite (SaD-I); and v) non-planar clear saddle dolomite (SaD-II). Fluid inclusions in ReD-SuD dolomite show a Th mode value of 205°C, while SaD-I and SaD-II show Th mode values of 235°C and 195°C respectively. Our research indicates that planar and non-planar dolomite textures are formed at high-temperatures under hydrothermal conditions in deep-burial diagenetic environments, unsupporting the accepted idea that planar dolomites are formed under temperatures around or less than 50-60°C in shallow-burial diagenetic environments.