Abstract
Phase relations and metamorphic conditions have been studied in metacarbonate rocks from the Nevado-Filábride Complex (Cordilleras Béticas) through forward modeling. In many rock samples, the assemblage titanite + rutile + calcite + quartz + graphite buffered the composition of the C-O-H fluid present during metamorphism. Over a wide range of P-T conditions, fluid compositions computed for this buffer are essentially binary H2O-CO2 mixtures. This buffer also constrains the chemical potentials of TiO2, CaO and SiO2. Consequently it is possible to make a thermodynamic projection through these components to predict the stable phase relations consistent with the buffer. Using this method, phase relations have been analyzed in a rock containing the buffer assemblage and paragonite, albite, phengite, epidote, and chlorite. The equilibrium P-T conditions for this assemblage are constrained, by minimization of the differences between predicted and observed mineral compositions, to be 560 ± 15 °C and 9.5 ± 1 kbar. Conditions obtained compare well with those estimated from other studies in different lithologic units. The inferred metamorphic fluid composition is H2O-rich ().
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 11 October 1995 / Accepted 5 August 1996
Rights and permissions
About this article
Cite this article
Sánchez-Vizcaíno, V., Connolly, J. & Gómez-Pugnaire, M. Metamorphism and phase relations in carbonate rocks from the Nevado-Filábride Complex (Cordilleras Béticas, Spain): application of the Ttn + Rt + Cal + Qtz + Gr buffer. Contrib Mineral Petrol 126, 292–302 (1997). https://doi.org/10.1007/s004100050251
Issue Date:
DOI: https://doi.org/10.1007/s004100050251