Elena Vindel

Fluid evolution and hydrothermal processes of the Spanish Central System

Fluids related to veins and hydrothermal alterations from the Spanish Central System have been studied. Fluid chemistry has been established using microthermometry and Raman spectroscopy. Special attention has been paid to the evolution of P–T conditions from early H2O–NaCl–CO2–CH4 to later H2O–NaCl–CaCl2 fluids. The different types of fluid systems investigated can be distinguished by their fluid pressure, temperature and salinity features. Under initial conditions the fluid pressure may be high, at lithostatic values, and show a nearly isobaric evolution. The later aqueous fluids drop to hydrostatic pressure with a transition to low pressures, in part due to uplift and erosion.

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 Riopar 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 205oC, while SaD-I and SaD-II show Th mode values of 235oC and 195oC 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 50-60oC in shallow-burial diagenetic environments.