000071100 001__ 71100 000071100 005__ 20230111103817.0 000071100 0247_ $$2doi$$a10.1016/j.chemgeo.2017.07.013 000071100 0248_ $$2sideral$$a101215 000071100 037__ $$aART-2017-101215 000071100 041__ $$aeng 000071100 100__ $$0(orcid)0000-0002-7383-9988$$aBlasco, Mónica$$uUniversidad de Zaragoza 000071100 245__ $$aGeochemistry, geothermometry and influence of the concentration of mobile elements in the chemical characteristics of carbonate-evaporitic thermal systems. The case of the Tiermas geothermal system (Spain) 000071100 260__ $$c2017 000071100 5060_ $$aAccess copy available to the general public$$fUnrestricted 000071100 5203_ $$aThe 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 chloride-sodium type and emerge with a temperature of about 37 °C. Two hydrogeochemical groups of waters have been distinguished: one with lower sulphate concentration and lower TDS (about 7500 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 combining several geothermometrical techniques: (1) classical chemical geothermometers (SiO2- quartz, Na-K, K-Mg and Na-K-Ca), (2) specific geothermometers for carbonate systems (Ca-Mg), (3) isotopic geothermometers and, (4) geothermometrical modelling. The good agreement in the temperature obtained by these techniques, including the cationic geothermometers which are not usually considered suitable for this type of systems, allows establishing a reliable range of temperature of 90 ± 20 °C for the low-sulphate waters and 82 ± 15 °C for the high-sulphate waters. The mineral assemblage in equilibrium in the reservoir is assumed to be the same for both groups of waters (calcite, dolomite, quartz, anhydrite, albite, K-feldspar and other aluminosilicate phases); therefore, the differences found in the reservoir temperature and, mostly, in the geochemical characteristics of each group of waters must be due to the existence of two flow paths, with slightly different temperatures and intensity of water-rock interaction. Anhydrite is at equilibrium in the reservoir suggesting that, although this system is hosted in carbonates, evaporites may also be present. The dissolution of halite (and the consequent increase in the chloride concentration) conditions the chemical characteristics of the waters and the equilibrium situations in the reservoir and waters acquire their chloride-sodium affinity at depth and not during their ascent to the surface. Finally, a favourable tectonic structure for CO2 storage has been recognised in the Paleocene-Eocene carbonates of this area. Therefore, considering the characteristics of these waters (in equilibrium with calcite, dolomite and anhydrite in the reservoir), the results of this work are useful to understand some of the geochemical processes that might take place during the CO2 injection: 1) precipitation of carbonates and sulphates in the vicinity of the injection well due to desiccation of the waters and, 2) carbonate dissolution and sulphate precipitation in the long term. 000071100 536__ $$9info:eu-repo/grantAgreement/ES/MEC/FPU14-01523 000071100 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/ 000071100 590__ $$a3.57$$b2017 000071100 591__ $$aGEOCHEMISTRY & GEOPHYSICS$$b19 / 85 = 0.224$$c2017$$dQ1$$eT1 000071100 592__ $$a1.755$$b2017 000071100 593__ $$aGeology$$c2017$$dQ1 000071100 593__ $$aGeochemistry and Petrology$$c2017$$dQ1 000071100 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion 000071100 700__ $$0(orcid)0000-0003-1463-1682$$aAuqué, Luis F.$$uUniversidad de Zaragoza 000071100 700__ $$0(orcid)0000-0001-5645-9150$$aGimeno, María J.$$uUniversidad de Zaragoza 000071100 700__ $$aAcero, Patricia 000071100 700__ $$aAsta, María P. 000071100 7102_ $$12000$$2685$$aUniversidad de Zaragoza$$bDpto. Ciencias de la Tierra$$cÁrea Petrología y Geoquímica 000071100 773__ $$g466 (2017), 696-709 [51 p.]$$pChem. geol.$$tCHEMICAL GEOLOGY$$x0009-2541 000071100 8564_ $$s579497$$uhttps://zaguan.unizar.es/record/71100/files/texto_completo.pdf$$yPostprint 000071100 8564_ $$s66378$$uhttps://zaguan.unizar.es/record/71100/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint 000071100 909CO $$ooai:zaguan.unizar.es:71100$$particulos$$pdriver 000071100 951__ $$a2023-01-11-10:04:18 000071100 980__ $$aARTICLE