641
storage 642
During the ALGECO2 project (IGME, 2010), a favourable tectonic and sedimentary 643
structure for CO2 storage was identified in the studied area (the Leyre-Berdún structure;
644
Suárez et al., 2014) in the Paleocene-Eocene carbonate rocks, which probably is the 645
aquifer of the Tiermas thermal waters. If the features of the waters in that structure are 646
similar to those deduced in the thermal waters, then some important conclusions about 647
some plausible processes effective during the CO2 injection could be drawn. For 648
example, in the vicinity of the injection well, the desiccation of the saline waters in 649
contact with dry CO2 could easily induce the precipitation of carbonates and sulphates 650
(Gaus, 2010; Gimeno et al., 2011; Gutierrez et al., 2011) as the waters at depth are in 651
equilibrium with calcite, dolomite and anhydrite. In the long term, injection of CO2 will 652
promote the acidification of the saline groundwaters, which will lead to the dissolution 653
of carbonate minerals (calcite and dolomite). In this context, precipitation of sulphates 654
(gypsum or anhydrite) may be triggered as the waters are in equilibrium with anhydrite 655
(e.g. with high concentrations of dissolved sulphate). A similar situation has been found 656
in the Spanish test site for CO2 geological storage, located at Hontomin (Burgos), in a 657
limestone reservoir, also with sulphate-rich saline groundwaters in equilibrium with 658
gypsum/anhydrite (García-Ríos et al., 2014).
659
These processes involving carbonate and sulphate minerals are kinetically fast and their 660
effects on the porosity and permeability of the reservoir rocks or in the well 661
environment should be evaluated in future and more detailed site selection studies.
662
6. Conclusions 663
Two hydrogeochemical groups of waters have been identified in Tiermas springs: a 664
group with TDS about 7,500 ppm and low sulphate contents (low-sulphate group) and 665
other with TDS close to 11,000 ppm and higher sulphate contents (high-sulphate 666
group).
667
The temperature of the waters in the reservoir has been determined by combining 668
various chemical and isotopic geothermometers with geothermometrical modelling, and 669
a reliable range of temperatures has been established. The temperatures predicted for the 670
waters are also slightly different for each group; being 90 ± 20 ºC for the low-sulphate 671
group and slightly lower 82 ± 15 ºC for the high-sulphate one.
672
It is remarkable the good results obtained with some cationic geothermometers, such as 673
the Na/K geothermometer, in a geothermal system of low temperature and hosted in 674
carbonate-evaporitic rocks like the studied here. This unusual situation may be 675
attributed to the presence of detrital rocks (silicate minerals) in the carbonate-evaporitic 676
aquifer, which provides for equilibrium between albite and K-feldspar as found in the 677
geothermometrical modelling.
678
The two water groups are in equilibrium with the same mineral assemblage in the 679
reservoir (calcite, dolomite, quartz, anhydrite, albite, K-feldspar and other 680
aluminosilicate phases). However they show slight differences in the temperature at 681
depth and in the concentration of some chemical elements, which suggests that each 682
group of waters could represent a different flow path with different types and/or 683
intensities of water-rock interaction processes.
684
The influence of halite dissolution has also been evaluated and the results indicate that 685
apart from temperature, chloride contents of the thermal waters have a significant 686
influence on the concentrations of SO4, Na, K, Ca and Mg measured in these waters. As 687
demonstrated in the simulations presented here, if halite dissolution had occurred during 688
the ascent of the thermal waters (without the influence of the mineral equilibria at 689
depth) their chemical characteristics would be different. These results, along with the 690
fact that anhydrite is included in the mineral assemblage in equilibrium in the reservoir, 691
indicate that the waters should be in contact with an evaporitic facies in the reservoir 692
and not during their ascent to surface.
693
Finally, as a favourable structure for CO2 storage has recently been identified in the 694
Paleocene-Eocene carbonates, the probable aquifer of the Tiermas geothermal system, 695
the groundwaters studied here could be used as analogues to the waters in that site.
696
Therefore, the results of this study are useful for understanding the main processes 697
related to the CO2 injection and mixing with this type of water. Near the injection wells, 698
the waters will desiccate causing the precipitation of calcite, dolomite and anhydrite, 699
since the waters are in equilibrium with respect to these phases in the reservoir, 700
affecting the porosity and permeability of the rocks. And in the long term, the water will 701
acidify leading to the carbonate dissolution and sulphate precipitation.
702
7. Acknowledgements 703
M. Blasco is working in this study thanks to a scholarship from the Ministry of 704
Education, Culture and Sports of Spain, for the Training of University Teachers (ref.
705
FPU14/01523). This study forms part of the activities of the Geochemical Modelling 706
Group (University of Zaragoza; Aragón Government). The comments of Dr. M.H. Reed 707
and of an anonymous reviewer have contributed to improve the work and are gratefully 708
appreciated.
709
Appelo, C.A.J. and Postma, D. (2005). Geochemistry, Groundwater and Pollution. 2nd 711
Edition. Rotterdam: A.A. Balkema.
712
Arnorsson, S., Gunnlaugsson, E. and Svavarsson, H. (1983). The chemistry of 713
geothermal waters in Iceland. III. Chemical geothermometry in geothermal 714
investigations. Geochimica et Cosmochimica Acta, 47, 567-577.
715
Asta, M.P, Gimeno, M.J., Auqué, L.F., Gómez, J., Acero, P. and Lapuente, P. (2010).
716
Secondary processes determining the pH of alkaline waters in crystalline rock 717
systems.Chemical Geology, 276, 41-52.
718
Auqué, L.F. (1993). Estudio de sistemas geotermales en Aragón. Pautas de especiación 719
y reacción aplicadas a la modelización de sistemas de baja - media entalpía.
720
Doctoral Thesis. Zaragoza, Spain: University of Zaragoza.
721
Ayora, C., Garcia-Veigas, J. and Puevo, J. (1994). The chemical and hydrological 722
evolution of an ancient potash-forming evaporite basin as constrained by mineral 723
sequence, fluid inclusion compostion and numerical simulation. Geochimica et 724
Cosmochimica Acta, 58, 3779-3794.
725
Ayora, C., Taberner, C., Pierre, C. and Pueyo J.J. (1995). Modeling the sulfur and 726
oxygen isotopic composition of sulfates through a halite-potash sequence:
727
Implications for the hydrological evolution of the Upper Eocene South Pyrenean 728
Basin. Geochimica et Cosmochimica Acta, 59, 1799 - 1808.
729
Awaleh, M.O., Hoch, F.B., Boschetti, T., Soubaneh, Y.D., Egueh, N.M, Elmi, S.K., 730
Mohamed, J. and Khaireh, M.A. (2015). The geotermal resources of the 731
Republic of Djibouti - II: Geochemical study of the Lake Abhe geothermal field.
732
Journal of Geochemical Exploration, 159, 129-147.
733
Baeza, J., Torreano, R. and Cerezuela, M.A. (2000). Estudio para caracterizar, evaluar y 734
proteger las aguas minerales y termales de una comunidad: Aragón. In: J.A.
735
López Geta and J.L. Pinuaga (Eds.), Panorama actual de las aguas minerales y 736
minero-medicinales en España. Madrid: Instituto Geológico y Minero de España 737
(IGME). pp. 283-303.
738
Bauluz, B., González, J.M., Yuste, A. and Mayayo, M.J. (2008). Evolución Diagenética 739
de las Turbiditas del Grupo Hecho (Eoceno) en la Cuenca de Jaca (España).
740
Revista de la sociedad española de mineralogía (Macla), 9, 47-48.
741
Boschetti, T. (2013). Oxygen isotope equilibrium in sulfate-water systems: A revisión 742
of geothermometric applications in low-enthalpy systems. Journal of 743
Geochemical Exploration, 124, 92-100.
744
Boschetti, T., Giampiero, V., Toscani, L., Barbieri, M. and Mucchino, C. (2005). The 745
Bagni di Lucca termal waters (Tuscany, Italy): an example of Ca-SO4 waters 746
with high Na/Cl and low Ca/SO4 ratios. Journal of Hydrology, 307, 270-293.
747
Boschetti, T., Cortecci, G., Toscani, L. and Iacumin, P. (2011). Sulfur and oxygen 748
isotope compositions of Upper Triassic sulfates from northern Apennines (Italy):
749
paleogeographic and hydrogeochemical implications. Geologica Acta, 9 (2), 750
129-147.
751
Brenninkmeijer, C.A.M., Kraft, P. and Mook, W.G. (1983). Oxygen isotope 752
fractionation between CO2 and H2O. Isotope Geoscience, 1, 181-190.
753
Chiba, H., Kusakabe, M., Hirano, S.I, Matsuo, S. and Somiya, A. (1981). Oxygen 754
isotope fractionation factors between anhydrite and water from 100 to 550°C.
755
Earth and Planetary Science Letters, 53, 55-62.
756
Chiodini, G., Cioni, R., Guidi, M. and Marini, L. (1991). Chemical geothermometry 757
and geobarometry in hydrothermal aqueous solutions: A theoretical investigation 758
based on a mineral-solution equilibrium model. Geochimica et Coscmochimica 759
Acta, 55, 2709-2727.
760
Chiodini, G., Frondini, F. and Marini, L. (1995). Theoretical geothermometers and 761
pCO2 indicators for aqueous solutions coming from hydrothermal systems of 762
medium-low temperature hosted in carbonate-evaporite rocks. Application to the 763
thermal springs of the Etruscan Swell. Italy. Applied Geochemistry, 10, 337-346.
764
Clark, I. and Fritz, P. (1997). Environmental Isotopes in Hydrogeology. Boca -Raton 765
(Florida): CRC Press/Lewis Publishers.
766
Consulnima S.L. (2011). Informe piezómetro de Romanzado: 090.031.001. Inspección 767
y vigilancia de las obras de Construcción de sondeos para la Adecuación de las 768
Redes de Piezometría y Calidad de las Aguas Subterráneas. Cuenca del Ebro.
769
Zaragoza: Confederación Hidrográfica del Ebro.
770
Craig, H. (1961). Isotopic variations in meteoric waters. Science, 133, 1702-1703.
771
D´Amore, F., Fancelli, R. and Caboi, R. (1987). Observations of the application of 772
chemical geothermometers to some hydrothermal systems in Sardinia.
773
Geothermics, 16, 271-282.
774
D’Amore F. and Arnórsson S. (2000). Geothermometry. In: Arnórsson S., (Ed.), 775
Isotopic and chemical techniques in geothermal exploration, development and 776
use (pp. 152-199). Vienna: International Atomic Agency.
777
Deines, P., Languir, D. and Harmon, R.S. (1974). Stable carbon isotope ratios and the 778
existence of a gas phase in the evolution of carbonate ground water. Geochimica 779
et Cosmochimica Acta, 38, 1147-1168.
780
Díaz-Teijeiro, M. F., Rodríguez-Arévalo, J. and Castaño, S (2009). La Red Española de 781
Vigilancia de Isótopos en la Precipitación (REVIP): distribución isotópica 782
espacial y aportación al conocimiento del ciclo hidrológico. Ingeniería Civil, 783
155, 87-97.
784
Faci, E. (Dir.) (1997). Cartografía Geológica de Navarra. E, 1:25000. Hoja 175-I:
785
Tiermas. Navarra: Gobierno de Navarra. Departamento de Obras Públicas, 786
Transportes y Comunicaciones.
787
Fernández, J., Auqué, L.F. Sánchez Cela, V.S. and Guaras, B. (1988). Las aguas 788
termales de Fitero (Navarra) y Arnedillo (Rioja). Análisis comparativo de la 789
aplicación de técnicas geotermométricas químicas a aguas relacionadas con 790
reservorios carbonatado-evaporíticos. Estudios geológicos, 44, 453-469.
791
Fournier, R.O. (1977). Chemical geothermometers and mixing models for geothermal 792
systems. Geothermics, 5, 41-50.
793
Fournier, R.O. (1979). A revised equation for the Na-K geothermometer. Geothermal 794
Resources Council Transactions, 3, 221-224.
795
Fournier, R.O. (1982). Water geothermometers applied to geothermal energy. In: (F.
796
D’Amore, Co-ordinator) Applications of Geochemistry in Geothermal reservoir 797
Development. UNITAR/UNDO centre on Small Energy Resources: Rome. pp.
798
37-69.
799
Fournier, R.O. and Truesdell, A.H. (1973). An empirical Na-K-Ca geothermometer for 800
natural waters. Geochimica et Cosmochimica Acta, 37, 1255-1275.
801
Fournier, R.O. and Potter, R.W. (1982). An equation correlating the solubility of quartz 802
in water from 25 to 900°C at pressures up to 10000 bars. Geochimica et 803
Cosmochimica Acta, 46, 1975-1978.
804
Friedman, I. and O'Neil, J.R. (1977). Compilation of stable isotope fractionation factors 805
of geochemical interest. In: M. Fleischer (Ed.), Data on Geochemistry (6th ed.).
806
Chapter KK. USGS Professional Paper 440-KK. Washington: United States 807
Government Printing Office.
808
Garcia-Rios, M., Cama, J., Luquot, L. and Soler, J.M. (2014). Interaction between CO2 -809
rich sulfate solutions and carbonate reservoir rocks from atmospheric to 810
supercritical CO2 conditions: Experiments and modeling. Chemical Geology, 811
383, 107-122.
812
Gaus, I. (2010). Role and impact of CO2-rock interactions during CO2 storage in 813
sedimentary rocks. International Journal of Greenhouse Gas Control, 4, 73-89.
814
Giggenbach, W., Gonfiantini, R., Jangi, B.L. and Truesdell, A.H. (1983). Isotopic and 815
chemical composition of Parbati valley geothermal discharges, N.W. Himalaya.
816
India. Geothermics, 12, 199‑222.
817
Giggenbach, W.F. (1988). Geothermal solute equilibria. Derivation of Na-K-Mg-Ca 818
geoindicators. Geochimica et Cosmochimica Acta, 52, 2749-2765.
819
Gimeno, M.J., Acero, P., Gutiérrez, V, Auqué, L.F., Asta, M.P. & Gómez, J.B. (2011).
820
Evaluation of thermodynamic data and activity coefficient models for the 821
geochemical modeling of CO2 storage systems. Mineralogical Magazine, 75(3):
822
918.
823
Grimaud, D,, Beaucaire, C. and Michard, G. (1990). Modelling of the evolution of 824
ground waters in a granite system at low temperature: the Stripa ground waters, 825
Sweden. Applied Geochemistry, 5, 515-525.
826
Gupta, K.D. and Pickering, K. T. (2008). Petrography and temporal changes in 827
petrofacies of deep-marine Aínsa-Jaca basin sandstone systems, Early and 828
Middle Eocene, Spanish Pyrenees. Sedimentology, 55, 1083-1114.
829
Gutiérrez, V., Acero, P., Auqué, L.F., Gimeno, M.J. (2011). Modelización geoquímica 830
de la evolución del entorno de un pozo de inyección de CO2 y evaluación de 831
condicionantes termodinámicos. Macla, 15.
832
Halas, S. and Pluta, I. (2000). Empirical calibration of isotope thermometer δ18O 833
(SO42−)-δ18O (H2O) for low temperature brines, In: V Isotope Workshop.
834
Kraków, Poland. pp. 68-71.
835
Hanor, J.S. (1994). Physical and chemical controls on the composition of waters in 836
sedimentary basins. Marine and Petroleum Geology, 11, 31-45.
837
Hanor, J.S. (1996). Variations of chloride as a driving force in siliciclastic diagenesis.
838
Siliciclastic Diagenesis and Fluid Flow: Concepts and applications, SEPM 839
Special Publication, 55, 3-12.
840
Hanor, J.S. (2001). Reactive transport involving rock-buffered fluids of varying 841
salinity. Geochmica et Cosmochimica Acta, 65, 3721-3732.
842
Helgeson, H.C. (1970). Description and interpretation of phase relations in geochemical 843
processes involving aqueous solutions. American Journal of Science, 268, 415-844
438.
845
Helgeson, H.C., Delany, J.M., Nesbitt, H.W. and Bird, D.K. (1978). Summary and 846
critique of the thermodynamic properties of rock-forming minerals. American 847
Journal of Science, 278ª.
848
IGME (1973). Mapa Geológico de España. E. 1:50000. Hoja 175: Sigües. Madrid:
849
Instituto Geológico y Minero de España (IGME).
850
IGME (2010). Selección y caracterización de áreas y estructuras geológicas favorables 851
para el almacenamiento geológico de CO2 en España.
852
http://info.igme.es/algeco2/ (accessed 21-03-2016).
853
ITGE-DGA (1994). Estudio de las aguas minero-medicinales, minero-industriales, 854
termales y de bebida envasada en la Comunidad Autónoma de Aragón. Madrid:
855
Instituto Geológico y Minero de España (IGME).
856
Jiménez, M. (1838). Tratado de materia farmacéutica (2ª ed.). Madrid: Imprenta de la 857
Viuda de Sanchiz e hijos.
858
Kharaka, Y.K. and Mariner, R.H. (1989). Chemical geothermometers from water-859
mineral equilibria. In: Abstracts of the 28th International Geological Congress 860
(vol. 2), Washington D.C. pp. 184-185.
861
Larrasoaña, J.C., Pueyo, E.I., del Valle, J., Millán, H., Pocoví, A. and Dinarés, J.
862
(1996). Datos magnetotectónicos del Eoceno de la Cuenca de Jaca - Pamplona:
863
resultados iniciales. Geogaceta, 30, 1058-1061.
864
Lloyd, R.M. (1968). Oxygen isotope behaviour in the sulfate-water system. Journal of 865
Geophysical Research, 73, 6099-6110.
866
López-Chicano, M., Cerón, J.C., Vallejos, A. and Pulido-Bosch, A. (2001).
867
Geochemistry of thermal springs, Alhama de Granada (southern Spain). Applied 868
Geochemistry, 16, 1153-1163.
869
Marini, L. (2004). Geochemical techniques for the exploration and exploitation of 870
geothermal energy. Genova: Laboratorio di Geochimica, Università degli Studi 871
di Genova.
872
Marini, L. Chidioni, G. and Cioni, R. (1986). New geothermometers for carbonate-873
evaporite geothermal reservoirs. Geothermics, 15, 77-86.
874
Marini, L., Bonaria, V., Guidi, M., Hunziker, J.C., Ottonello, G., and Vetuschi 875
Zuccolini, M. (2000). Fluid geochemistry of the Acqui Terme-Visone 876
geothermal area (Piemonte, Italy). Applied Geochemistry, 15, 917-935.
877
Merino, E. and Ramson, B. (1982). Free energies of formation of illite solid solutions 878
and their compositional dependence. Clays and Clay Minerals, 30, 29-39.
879
Mey, P.H.W., Nagtegaal, P.J.C., Roberti, K.J. and Hartevelt, J.J.A. (1968).
880
Lithostratigraphic subdivision of post-hercynian deposits in the south-central 881
Pyrenees, Spain. Leidse Geologische Mededelingen, 41, 221-228.
882
Michard, G. (1979). Géothermomètres chimiques. B.R.G.M. (2nd Ser.), section III, 2, 883
183-189.
884
Michard, G. (1987). Controls of the chemical composition of geothermal waters. In:
885
H.C. Helgeson (ed.), Chemical Transport in Metasomatic Processes (pp. 323-886
Michard, G. and Fouillac, C. (1980). Contrôle de la composition chimique des eaux 888
thermals sulfurées sodiques du Sud de la France. In: Tardy, Y. (Ed.), 889
Geochimique des interactions entre les eaux, les minéraux et les roches.
890
Elements: Tarbes, pp. 147-166.
891
Michard, G. and Roekens, E. (1983). Modeling of the chemical composition of alkaline 892
hot waters. Geothermics, 12, 161-169.
893
Michard, G., Sanjuan, B., Criaud, A., Fouillac, C., Pentcheva, E.N., Petrov, P.S. and 894
Alexieva, R. (1986). Equilibra and geothermometry in hot waters from granites 895
of SW Bulgaria. Geochemical Journal, 20, 159-171.
896
Michard, G. and Bastide, J.P. (1988). Etude Geochimique de la nappe du Dogger du 897
Bassin Parisien. Journal of Volcanology and Geothermal Research, 35, 151-163.
898
Michard, G., Pearson, F.J.Jr. and Gautschi, A. (1996). Chemical evolution of waters 899
during long term interaction with granitic rocks in northern Switzerland. Applied 900
Geochemistry, 11, 757-774.
901
Mizutani, Y. and Rafter, T.A. (1969). Oxygen isotopic composition of sulphates. 3.
902
Oxygen isotopic fractionation in the bisulfate ion-water system. New Zeland 903
Journal of Science, 12, 54-59.
904
Mook, W.G., Bommerson, J.C. and Staverman, W.H. (1974). Carbon isotope 905
fractionation between dissolved bicarbonate and gaseous carbon dioxide. Earth 906
and Planetary Science Letters, 22, 169-176.
907
Nordstrom, D.K., Ball, J.W., Donahoe, R.J. and Whittemore, D. (1989). Groundwater 908
chemistry and water-rock interactions at Stripa. Geochimica et Cosmochimica 909
Acta, 53, 1727-1740.
910
Nordstrom, D. K., Plummer, L. N., Langmuir, L., Busenberg, E., May, H. M., Jones, B.
911
F. and Parkhurst, D. L. (1990). Revised chemical equilibrium data for major 912
water-mineral reactions and their limitation. In: Melchior, D.C. and Basset, R.L.
913
(Eds.), Chemical Modeling of Aqueous Systems II. Symposium Series 416.
914
Washington DC: American Chemical Society. pp. 398-413.
915
Oliva, B., Millán, H., Pocoví, A. and Casas A.M. (1996). Estructura de la Cuenca de 916
Jaca en el sector occidental de las Sierras Exteriores Aragonesas. Geogaceta, 20, 917
800-802.
918
Olivia-Urcia, B., Casas, A.M., Pueyo, E.L. and Pocoví-Juan, A. (2012). Structural and 919
paleomagnetic evidence for non-rotanional kinematics of the South Pyrenean 920
Frontal Thrust at the western termination of the External Sierras (southwestern 921
central Pyrenees). Geologica Acta, 10, 125-144.
922
O’Neil, J.R. and Adami, L. H. (1969). The oxygen isotope partition function ratio of 923
water and the structure of liquid water. Journal of Physical Chemistry, 73 (5), 924
1553-1558.
925
Palandri, J.L. and Reed M.H. (2001). Reconstruction of in situ composition of 926
sedimentary formation waters. Geochimica et Cosmochimica Acta, 65, 1741-927
1767.
928
Pang, Z. and Reed, M.H. (1998). Theoretical chemical thermometry on geothermal 929
waters: Problems and methods. Geochimica et Cosmochimica Acta, 62, 1083-930
1091.
931
Parkhurst, D.L. and Appelo, C.A.J. (2013). Description of Input and Examples for 932
PHREEQC Version 3. A Computer Program for Speciation, Batch‐Reaction, 933
Geological Survey (Ed.). Techniques and Methods, book 6, chap. A43, Denver, 935
Colorado: U.S.G.S., available only at http://pubs.usgs.gov/tm/06/a43.
936
Pastorelli, S., Marini, L. and Hunziker, J.C. (1999). Water chemistry and isotope 937
composition of the Acquarossa thermal system, Ticino, Switzerland.
938
Geothermics, 28, 75-93.
939
Payros, A., Orue-Etxebarria, X., Bacera, J.I. and Pujalte, V. (1994). Las 940
“megaturbiditas” y otros depósitos de resedimentación carbonatada a gran escala 941
del Eoceno surpirenaico: nuevos datos del área Urrobi-Ultzama (Navarra).
942
Geogaceta, 16, 94-97.
943
Peiffer, L., Wanner, C., Spycher, N., Sonnenthal, E.L., Kennedy, B.M., Iovenitti, J.
944
(2014). Optimized multicomponent vs. classical geothermometry: Insights from 945
modeling studies at the Dixie Valley geothermal area. Geothermics, 51, 154-946
169.
947
Pueyo, E.L., Calvin, P., Casas, A.M., Olivia-Ucria, B., Klimowitz, J., Garcia-Lobón, 948
J.L., Rubio, F.M., Ibarra, P.I., Martínez-Duran, P., Rey-Moral, M.C., Pérez, I.
949
and Martín, J. M. (2012). A research plan for a large potential CO2 reservoir in 950
the Southern Pyrenees. Geotemas, 13, 1970-1973.
951
Puigdefàbregas, C. (1975). La sedimentación molásica en la cuenca de Jaca. Pirineos, 952
104.
953
Reed, M. and Spycher, N. (1984). Calculation of pH and mineral equilibria in 954
hydrothermal waters with application to geothermometry and studies of boiling 955
and dilution. Geochimica et Cosmochimica Acta, 48, 1479-1492.
956
Sáenz, C. (1999). Patrimonio geológico del Camino de Santiago. Madrid: Instituto 957
Tecnológico GeoMinero de España.
958
Sánchez Guzmán, J. and García de la Noceda, C. (2005). Geothermal Energy 959
Development in Spain - Country Update Report. In: Proceedings World 960
Geothermal Congress 2005. Antalya, Turkey. pp. 1-10 961
Sánchez, J.A. (2000). Las aguas termales en Aragón: Estudio hidrogeotérmico.
962
Zaragoza: Consejo de Protección de la Naturaleza de Aragón.
963
Sánchez, J.A., Coloma, P., Pérez-García, A. and De Leiva, A. (2000). Evaluación del 964
flujo geotérmico en manantiales de Aragón. Geogaceta, 27, 155-158.
965
Sánchez, J.A., Colom, P. and Pérez-García, A. (2004). Evaluation of geothermal flow at 966
the springs in Aragón (Spain), and its relation to geologic structure.
967
Hydrogeology Journal, 12, 601-609.
968
Saura, E. and Teixell, A. (2006). Inversion of small basins: effects on structural 969
variations at the leading edge of the Axial Zone antiformal stack (Southern 970
Pyrenees, Spain). Journal of Structural Geology, 28, 1909-1920.
971
Seal, R.R.I., Alpers, C.N. and Rye, R.O. (2000). Stable isotope systematics of sulfate 972
minerals. In: C.N. Alpers, J.L. Jambor, and D.K Nordstrom, D.K. (Eds.), Sulfate 973
Minerals — Crystallography: Geochemistry and Environmental Significance 974
(pp. 541-602). Chantilly (Virginia): Mineral Society of America.
975
Spycher, N., Peiffer, L., Sonnenthal, E.L., Saldi, G., Reed, M.H.; Kennedy, B.M.
976
(2014). Integrated multicomponent solute geothermometry. Geothermics, 51, 977
113-123.
978
Suárez, I., Arenillas, A., Medaito, J.F., García, J., Molinero, R. and Catalina, R. (2014).
979
Atlas de estructuras del subsuelo susceptibles de almacenamiento geológico de 980
CO2 en España. Madrid: Instituto Geológico y Minero de España (IGME).
981
Instituto para la Reestructuración de la Minería del carbón y desarrollo 982
Alternativo de las Comarcas Mineras.
983
Tole, M.P., Armannsson, H., Pang, Z. and Arnorsson, S. (1993). Fluid/mineral 984
equilibrium calculations for geothermal fluids and chemical geothermometry.
985
Geothermics, 22, 17-37.
986
Trotignon L., Beaucaire, C., Louvat, D. and Aranyossy, J.F. (1999). Equilibrium 987
geochemical modelling of Äspö groundwaters: a sensitivity study of 988
thermodynamic equilibrium constants. Applied Geochemistry, 14, 907-916.
989
Truesdell, A.H. (1974) Oxygen isotope activities and concentrations in aqueous salt 990
solutions at elevated temperatures: Consequences for isotope geochemistry.
991
Earth Planet Science Letters, 23, 387-396.
992
Truesdell, A.H. (1976). Geochemical Techniques in Exploration. Summary of Section 993
III. In: Proceedings of the Second United Nations Symposium on the 994
Development and Use of Geothermal Resources. San Francisco, California. pp.
995
iii-xxix 996
Utrilla, R., Pierre, C., Ortí, F., Rosell, L., Inglés, M. and Pueyo, J.J. (1987). Estudio 997
isotópico de los sulfatos en formaciones evaporíticas mesozoicas y terciarias 998
continentales. In: II Congreso de Geoquímica de España. Soria. pp. 91-94.
999
Wang, J., Jin, M., Jia, B. and Kang, F. (2015). Hydrochemical characteristics and 1000
geothermometry applications of thermal groundwater in northern Jinan, 1001
Shandong, China. Geothermics, 57, 185-195.
1002
Zeebe, R.E. (2010). A new value for the stable oxygen isotope fractionation between 1003
dissolved sulfate ion and water. Geochimica et Cosmochimica Acta, 74, 818-1004
828.
1005
Zheng, Y.F. (1999). Oxygen isotope fractionation in carbonate and sulfate minerals.
1006
Geochemical Journal, 33, 109-126.
1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022
1023
Figure 1 1024
1025
Figure 2 1026
1027
1028
1029
Figure 3 1030
1031
1032
1034
Figure 5 1035
1036
Figure 6 1037
1038 1039 1040 1041 1042 1043 1044
1045
Figure 7 1046
1047 1048 1049
Figure captions 1050
Figure 1. Location of the Tiermas geothermal system and geological map of the area (modified from Oliva-Urcia et
1051
al., 2012).
1052
Figure 2. Cross section showing the general structure of the Jaca-Pamplona Basin and the location of Tiermas
1053
Springs (modified from ALGECO2 project: http://info.igme.es/algeco2/; IGME, 2010).
1054
Figure 3. δ2H – δ18O diagram showing the isotopic composition of sample T1, two samples from the Yesa Reservoir
1055
(one taken in 1985 and the other in 2012, this last one still unpublished) and one sample from a borehole in Tiermas
1056
from the study performed by Baeza et al. (2000). The Global Meteoric Water Line (GMWL), the Regional Meteoric
1057
Water Line (RMWL) and Local Meteoric Water Line (LMWL) are also represented.
1058
Figure 4. Location of all the samples in the Giggenbach diagram. The dotted line is calculated with the Na-K
1059
Fournier (1979) calibration and with the Giggenbach (1988) one for Mg-K; the solid line is calculated with Na-K and
1060
Mg-K calibrations of Giggenbach (1988). If the dotted line is considered, the samples of the group 2 are close of
1061
being fully equilibrated.
1062
Figure 5. Evolution with temperature of the saturation indices of the minerals supposed to be in equilibrium with the
1063
water of samples T1 (a) and B1 (b) in the reservoir. These results were obtained after the theoretical CO2 addition to
water of samples T1 (a) and B1 (b) in the reservoir. These results were obtained after the theoretical CO2 addition to