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The Tiermas low temperature geothermal system, hosted in the Paleocene-Eocene carbonates of the Jaca-Pamplona basin, has been studied to evaluate the geochemistry and the temperature of the waters in the deep reservoir. These waters are of chloridesodium type and emerge with a temperature of about 37 ºC. Two hydrogeochemical groups of waters have been distinguished: one with lower sulphate concentration and lower TDS (about 7,500 ppm) and the other with higher sulphate content and TDS values (close to 11,000 ppm). There are also slight differences in the reservoir temperature estimated for each group. These temperatures have been determined by in the vicinity of the injection well due to desiccation of the waters and, 2) carbonate dissolution and sulphate precipitation in the long term.

The Fitero and Arnedillo geothermal systems are located in the NW part of the Iberian Range (Northern Spain). The geothermal reservoir is hosted in the Lower Jurassic carbonates, in contact with the evaporitic Keuper Facies. Thermal waters are of chloride-sodium type, with discharge temperature of about 45 ºC and near neutral pH. The Arnedillo waters are more saline, with higher Na, Cl and sulphate contents, but lower Ca and Mg than the Fitero waters. All waters have attained mineral equilibrium at 2 depth with calcite, dolomite, anhydrite, quartz, albite, K-feldspar and other aluminosilicates, except for the Fitero waters, which have not reached the equilibrium with the aluminosilicates. The calculated reservoir temperature is 81 ± 11 ºC in Fitero and 87 ± 13 ºC in Arnedillo. In order to identify the reasons for the differences found between the two systems some inverse and forward geochemical calculations were performed and the main water-rock interaction processes responsible for the chemical evolution of these waters have been evaluated. Halite dissolution has been found to be the triggering factor for the two most important geochemical processes in the system: a) albitisation process, due to the common ion effect (Na); and b) dedolomitisation process, associated with the salinity increase, which enhance the dissolution of anhydrite, and, in turn, produces the precipitation of calcite (common ion effect, Ca) and the concomitant dissolution of dolomite. Halite dissolution may be an important driving force in the geochemical evolution of groundwater systems in contact with carbonates and evaporites, where equilibrium with K-feldspar, albite and anhydrite has already been attained. The evolution of the processes at pH, temperature and salinity ranges wider than those in the Fitero-Arnedillo system has been theoretically examined with additional reaction-path simulations, in order to generalise the geochemical behaviour of these processes in other environments.

Agresividad en menores de 18 años jugadores de fútbol: Diferencias en función del sexo y la edad y en comparación con los jugadores de baloncesto Aggression in under 18 soccer players: Differences in by sex and age and compared to basketball players Agresividade com menos de 18 jogadores de futebol: Diferenças em por sexo e idade e comparados com os jogadores de basquete

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