Modelos de balance de masas aplicados a sistemas geotermales del Pirineo Central
- Autores: S. García Sanz, Belén Buil Gutiérrez, Marceliano Lago San José, Enrique Arranz Yagüe
- Localización: Geotemas (Madrid), ISSN 1576-5172, Nº. 1, 2, 2000 (Ejemplar dedicado a: V Congreso Geológico de España (Alicante, 10-14 julio 2000)), págs. 79-82
- Idioma: español
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Resumen
In this paper, we deal with three geothermal systems (Caldas de Boi, Arties and Tredos), hostedby the granodiorites and syenogranites of the Maladeta Plutonic Complex (MPC; Central Spanish Pyrenees). Waters from these three systems are chemically similar; Na/Si and Na/Al ratios arehigher in the waters when compared to the same ratios in the host rocks, as a consequence of being Na the main cation in the waters. Mass-balance modelling has been applied on these three systems, leading us to three models of water-rock interaction, operating over the flow path; these models give a reasonable explanation, thermodinamically and petrologically consistent, to the final composition of the waters. Ions are dissolved by means of the destabilization off eldspars and chlorite/biotite. Excess ions are precipitated in the form of mineral buffers (kaolinite,chrysotile, illite/smectite, Ca-montmorillonite, calcite/prehnite and muscovite). Finally, coupledCa/Na ionic exchange and SiO /Mg-silicates precipitation processes are proposed to explain the high Na concentrations in solution.
