Skip to main content

Cation site occupancy in chlorites and illites as a function of temperature

  • M. Cathelineau (a1)

The relationships between the composition and the crystallization temperature of chlorites and illites have been investigated in different geothermal fields and in particular the Los Azufres system in Mexico, considered to be a natural analogue to experimental laboratories, as the main changes in physical and chemical conditions and mineralogy are related to progressively increasing temperature with depth. Temperature was estimated from combined geothermometric approaches, and especially from fluid inclusion studies on quartz coexisting with clays. The Al(IV) content in the tetrahedral site of chlorites, and the K content and total interlayer occupancy of illites increase with temperature. These chemical changes are mainly related to the marked decrease in the molar fraction of the Si(IV)-rich end-members (kaolinite for chlorites, and pyrophyllite for illites) which become negligible at ∼300°C. Other chemical changes, such as the variation in Fe and Mg contents, are partly influenced by temperature, but are strongly dependent on the geological environment, and consequently on the solution composition. The empirical relationships between chemical variables and temperature were calibrated from 150–300°C, but extrapolations at lower and higher temperatures seem possible for chlorites. Such geothermometers provide tools for estimating the crystallization temperature of the clays, and are important for the study of diagenetic, hydrothermal and low-T metamorphic processes.

Hide All
Aagaard, P. & Helghson, H.C. (1983) Activity/composition relations among silicates and aqueous solutions. II: Chemical and thermodynamic consequences of ideal mixing of atoms on homological sites in montmorillonites, illites and mixed-layer clays. Clays Clay Miner. 31, 207–217.
Aagaard, P., Roaldset, E. & Welhaven, J.E. (1988) Diagenetic observations from North Sea sandstone reservoirs: a comparison with formation water chemistry. "Clay diagenesis in hydrocarbon reservoirs and shales" Meeting, Cambridge, March 1988.
Audéoud D. (1982) Les mineralisations uraniferes et leur environnement a Kamoto, Kambove et Shinkolobwe ﹛Shaba, Zaire) petrographie, geochimie et inclusions fluides. Thesis, Univ. Lyon, France.
Bishop, B.P. & Bird, D.K. (1987) Variation in sericite compositions from fracture zones within the Coso hot springs geothermal system. Geochim. Cosmochim. Acta 51, 1245–1256.
Bragg, W.L. (1937) Atomic Structure of Minerals. Ithaca: Cornwell University Press.
Bragg, L. & Claringbull, G.F. (1965) Crystal Structures of Minerals. G. Bell & Sons, Ltd., London.
Cathelineau, M. & Nieva, D. (1985) A chlorite solid solution geothermometer. The Los Azufres geothermal system (Mexico). Contrib. Mineral. Pet. 91, 235–244.
Cathelineau, M., Oliver, R., Nieva, D. & Garifas, A. (1985) Mineralogy and distribution of hydrothermal mineral in Los Azufres (Mexico) geothermal field. Geothermics 14, 49–57.
Cathelineau, M. (1987) Les interactions entre fluides et mineraux: thermometrie et modelisation. Lexemple d'un systeme geothermique actif (Los Azufres, Mexique) et (('alterations fossiles dans la Chaine Varisque. Doct. Thesis,I.NP .Nancy, France.
Cathelineau, M., Oliver, R. & Nieva, D. (1987) Quaternary volcanic series of the Los Azufres geothermal field (Mexico). Special vol. on Mexican Volcanic Belt. Part. 3 (Verma, S. P., editor), Geof. Int. 26, 273–290.
Cathelineau, M. & Izquierdo, G. (1988) Temperature-composition relationships for authigenic clay minerals in the Los Azufres geothermal system. Contrib. Mineral. Pet. (in press).
Cathelineau, M., Izquierdo, G. & Nieva, D. (1988) Thermobarometry of hydrothermal alteration in the Los Azufres geothermal system: significance of fluid inclusion data. Chem. Geol. (in press).
Cavaketta, G., Gianelli, G. & Puxeddu, M. (1982) Formation of authigenic minerals and their use as indicators of the chemico-physica] parameters of the fluid in the Larderello-Travele geothermal field. Econ. Geol. 77, 1071–1084.
Dunoyer De Segonzac, G. (1970) The transformation of clay minerals during diagenesis and low-grade metamorphism. A review. Sedimentology 15, 281–346.
Elders, W.A. (1979) The geological background of the geothermal field of the Salton Trough. Pp. 119 in: Geology and Geotermics of the Salton Trough. (Elders, W. A., editor) Geol. Soc. Am. Guidebook No 7, San Diego.
Fournier, R.O. & Truesdell, A.H. (1973) An empirical Na-Ca-Ca geothermometer for natural waters. Geochim. Cosmochim. Acta 47, 579–586.
Fournier, R.O. & Potter, R.W. (1982) A revised and expanded silica (quartz) geothermometer. Geochim, Cosmochim. Acta 43, 1543–1550.
Freckman, J.T. (1978) Fluid inclusion and oxygen isotope geothermometry of rock samples from Sinclair 4 and Elmore 1 boreholes, Salton Sea Geothermal Field, Imperial Valley, California, USA. Inst. Geophys. Planetary Phys., Univ. Calif., Riverside, Rep. 78/5, 66pp.
Frey, M., Teichmuller, M., Teichmuller, R., Mullis, J.( Kunzi, B., Breitschmid, A., Gruner, V. & Schwizer, B. (1980) Very low grade metamorphism in external part of the Central part of the Central Alps: Illite cristallinity, coal rank, and fluid inclusion data. Eclogae geol. Helv. 73, 173–203.
Fritz, B. (1981) Etude thermodynamique et modelisation des reactions hydrothermales et diagenetiques. Sci. Geol. Mem. 65, 197 pp.
Gutierrez, A.N. & Aumento, F. (1982) The Los Azufres, Michoacan, Mexico, geothermal field. J. HydroL 56, 137–162.
Helgeson, H.C. (1968) Geologic and thermodynamic characteristics of the Salton sea Geothermal system. Am. J. Sci. 266, 129–166.
Kublhr, B. (1967) La cristallinite de Tillite et les zones tout a fait superieures du metamorphisme. Etages tectoniques. Coll. Neuchatel 105122.
Kubler, B. (1969) Evaluation quantitative du metamorphisme par la cristallinite de Tillite. Bull Centre Rech. Pau, SNPA 212, 385-397.
McDowell, S.D. & Elders, W.A. (1980) Authigenic layer silicate minerals in borehole Elmore 1, Salton Sea geothermal field, California, USA. Contrib. Mineral. Pet. 74, 293–310.
Meunier, J.D. (1984) Les phenomenes d'xydo-reduction dans un gisement urano-vanadifere de type tabulaire: les gres du Salt-Wash (Jurassique Superieur), district minier de Cottonwood-Wash (Utah, Etats Unis). Geol. Geoch. Uranium, Mem. Nancy 4, 200 pp.
Nieva, D., Quijano, L., Garfias, A., Barragan, R.M. & Laredo, F. (1983) Heterogeneity of the liquid phase, and vapor separation in the Los Azufres (Mexico), geothermal reservoir. Proc. 9th Workshop Geothermal Res. Eng. Stanford Univ. SGP-TR-74.
Perry, E.A. & Hower, J. (1970) Burial diagenesis in Gulf Coast pelitic sediments. Clays Clay Miner. 18,165-178.
Reynolds, R.C. & Hower, J. (1970) The nature of interlayering in mixed-layered illite-montmorillonites. Clays Clay Miner. 18, 25–36.
Schoen, R. & White, D.E. (1966) Hydrothermal clay minerals in granodiorite in the Main Terrace Steambot Springs, Nevada. Clays Clay Miner. 13, 121–122.
Steiner, A. (1968) Clay minerals in hydrothermally altered rocks at Wairakei, New Zealand. Clays Clay Miner. 16, 193–213.
Stoessel, R.K. (1979) A regular site-mixing model for illites. Geochim. Cosmochim. Acta 43, 1151–1159.
Stoessel, R.K. (1984) Regular solution site-mixing model for chlorites. Clays Clay Miner. 32, 205–212.
Sveibjornsdottir, A. (1986) The chemical characteristics of the hydrothermal fluids at the Krafla and Reykjanes systems, as inferred from the coexisting mineralogy. Proc. 5th Int. Sym. Water Rock Interaction, Reykjavik, Iceland 546549.
Tardy, Y. & Fritz, B. (1981) An ideal solid solution model for calculating solubility of clay minerals. Clay Miner. 16, 361–373.
Thompson, J.B. Jr. & Thompson, A.B. (1976) A model system for mineral facies in pelitic schists. Contrib. Mineral. Pet. 58, 3–55.
Thompson, J.B., Laird, J. & Thompson, A.B. (1982) Reactions in amphibolite, greenschist and blueschist. J. Pet. 1, 1–27.
Tomason, J. & Kristmannsdottir, H. (1972) High temperature alteration minerals and thermal brines, Reykjanes, Iceland. Contrib. Mineral. Pet. 36, 123–134.
Velde, B. (1977) Clays and clay minerals in natural and synthetic systems. Developments in Sedimentology, 21. Elsevier, Amsterdam.
Velde, B. (1985) Clay minerals. A physico-chemical explanation of their occurrence. Developments in Sedimentology, 40. Elsevier, Amsterdam
Weaver, C.E. (1959) The clay petrology of sediments. Clays Clay Miner. 6, 154187.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Clay Minerals
  • ISSN: 0009-8558
  • EISSN: 1471-8030
  • URL: /core/journals/clay-minerals
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed