Hostname: page-component-848d4c4894-v5vhk Total loading time: 0 Render date: 2024-06-26T11:51:26.717Z Has data issue: false hasContentIssue false
  • English
  • Français

Mechanism of Illitization of Bentonites in the Geothermal Field of Milos Island Greece: Evidence Based on Mineralogy, Chemistry, Particle Thickness and Morphology

Published online by Cambridge University Press:  28 February 2024

George E. Christidis
George E. Christidis*
Affiliation:
Technical University of Crete, Department of Mineral Resources Engineering, 73133 Chania, Crete, Greece
Get access Rights & Permissions [Opens in a new window]

Abstract

Hydrothermal alteration has caused illitization along a 40m vertical profile in the Tsantilis bentonite deposit, Eastern Milos, Greece which consists principally of a Wyoming-type montmorillonite and authigenic K-feldspar. The product K-bentonite which contains illite/smectite, kaolinite, K-feldspar, quartz, sulphates and sulphides exhibits an unusual tendency for increase of expandability with depth.

Mineralogy and I/S textures were determined with X-ray diffraction and SEM and TEM methods respectively and chemistry using X-ray fluorescence. Illitization is characterized by a 5- to 6-fold increase of K and release of Si, Fe, Mg Na, and Ca from the parent rock, indicating a K-influx (K-metasomatism) in the system.

The I/S particle morphology is characterized by both flaky and lath-like particles, the former dominating in the range 100-50% expandable layers (R0 ordering) and the latter in the range 50-10% expandable layers (R1 and R > 1 ordering). Flaky particles are also abundant in samples with R1 ordering and abundant kaolinite, indicating that the latter might affect illitization. The I/S particles are classified in populations with thickness multiples of 10 A, their thickness being probably smaller than the coherent XRD domain. As the reaction proceeds, particles grow thicker and more equant. The distribution of I/S particle dimensions forms steady state profiles showing log-normal distribution; however, sensu stricto Ostwald ripening is unlikely. It seems that the reaction proceeds toward minimization of the surface free energy of I/S, being affected principally by temperature and K-availability. The spatial distribution of expandability implies that the heating source was probably a mineralized vein with T < 200°C, directed away from the bentonite, suggesting that illitization might be used as an exploration guide for mineral deposits.

Keywords

BentoniteHydrothermal alterationIllitizationIllite/smectiteKaoliniteNeoformationOstwald ripeningSolid state transformation
Type
Research Article
Information
Clays and Clay Minerals , Volume 43 , Issue 5 , October 1995 , pp. 569 - 585
Copyright
Copyright © 1995, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Ahn, J. H., and Buseck, P. R. 1990. Layer-stacking sequences and structural disorder in mixed-layer illite/smectite: Image simulations and HRTEM imaging. Am. Miner. 75: 267–275.Google Scholar
Altaner, S. P., Hower, J., Whitney, G., and Aronson, J. L. 1984. Model for K-bentonite formation: Evidence from zoned K-bentonites in the disturbed belt, Montana. Geology 12: 412–415.Google Scholar
Baronnet, A., 1982. Ostwald ripening in solution. The case of calcite and mica. Estud. Geol. 38: 185–198.Google Scholar
Baronnet, A., 1984. Growth kinetics of the silicates. A review of the basic concepts. Fortschr. Miner. 62: 187–232.Google Scholar
Bennett, H., and Oliver, G. J. 1976. Development of fluxes for the analysis of ceramic materials by X-ray Spectrometry. Analyst. 101: 803–807.Google Scholar
Bethke, G. M., and Altaner, S. P. 1986. Layer by layer mechanism of smectite illitization and application to a new rate law. Clays & Clay Miner. 34: 136–145.Google Scholar
Beutelspacher, H., and van der Marel, H. W. 1968. Atlas of Electron Microscopy of Clay Minerals and Their Admixtures. Amsterdam: Elsevier, 333 pp.Google Scholar
Boles, J. R., and Franks, S. G. 1979. Clay diagenesis in Wilcox Sandstones of Southwest Texas: Implications of smectite diagenesis on sandstone cementation. J. Sed. Pet. 49: 55–70.Google Scholar
Brusewitz, A. M., 1986. Chemical and physical properties of Paleozoic potassium bentonites from Kinnekulle, Sweden. Clays & Clay Miner. 34: 442–454.Google Scholar
Chai, B. H. T., 1974. Mass transfer of calcite during hydro-thermal recrystallization. In Geochemical Transport and Kinetics. Hoffmann, A. W., Giletti, B. J., Yoder, H. S. Jr., and Jund, R. A., eds. Washington: Carnegie Inst, 205–218.Google Scholar
Christidis, G., 1992. Origin, physical and chemical properties, of the bentonite deposits from the Aegean Islands of Milos, Kimolos and Chios, Greece. Ph.D. thesis. Univ. Leicester, UK. 472 pp.Google Scholar
Christidis, G., and Dunham, A. C. 1993. Compositional variations in smectites: Part I: Alteration of intermediate volcanic rocks. A case study from Milos Island, Greece. Clay Miner. 28: 255–273.Google Scholar
Christidis, G., and Marcopoulos, T. 1993. Kaolinite generating processes in the Milos bentonites and their influence on the physical properties of bentonites. Bull. Geol. Soc. Greece (in press).Google Scholar
Christidis, G., Scott, P. W., and Marcopoulos, T. 1995. Origin of the bentonite deposits of Eastern Milos, Aegean, Greece: Geological, mineralogical and geochemical evidence. Clays & Clay Miner. 43: 63–77.Google Scholar
Eberl, D. D., 1978. The reaction of montmorillonite to mixed-layer clay: The effect of interlayer alkali and alkaline earth cations. Geochim. Cosmochim. Acta. 42: 1–7.Google Scholar
Eberl, D. D., Whitney, G., and Khoury, H. 1978. Hydro-thermal reactivity of smectite. Am. Miner. 63: 401–409.Google Scholar
Eberl, D. D., and Srodon, J. 1988. Ostwald ripening and interparticle-diffraction effects for illite crystals. Am. Miner. 73: 1335–1345.Google Scholar
Eberl, D. D., Srodon, J., and Northrop, H. R. 1986. Potassium fixation in smectite by wetting and drying. In Geochemical Processes at Mineral Surfaces. Davis, J. A., and Hayes, K. F., eds. Amer. Chem. Soc. Symp. Ser. 323: 296–326.Google Scholar
Eberl, D. D., Srodon, J., Kralik, M., Taylor, B. E., and Peterman, Z. E. 1990. Ostwald ripening of clays and meta-morphic minerals. Science 248: 474–477.Google Scholar
Eberl, D. D., Velde, B., and McCormick, T. 1993. Synthesis of illite-smectite from smectite at earth surface temperatures and high pH. Clay Miner. 28: 49–60.Google Scholar
Fyticas, M., 1977. Geological and Geothermal and Study of Milos Island. Ph.D thesis. Univ. Thessaloniki, Greece, 228 pp. (in Greek).Google Scholar
Fyticas, M., Innocenti, F., Kolios, N., Manetti, P., Mazzuoli, R., Poli, G., Rita, F., and Villari, L. 1986. Volcanology and petrology of volcanic products from the island of Milos and neighbouring islets. J. Volcanol. Geotherm. Res. 28: 297–317.Google Scholar
Glasmann, J. R., Lundegard, P. D., Clark, R. A., Penny, B. K., and Collins, I. D. 1989. Geochemical evidence for the history of diagenesis and fluid migration: Brent Sandstone, Heather Field, North Sea. Clay Miner. 24: 255–284.Google Scholar
Govindaraju, K., 1989. Geostandards Newsletter 13: Spec. Issue, July 1989.Google Scholar
Güven, N., 1974. Electron Optical investigations on mont-morillonites-I. Cheto, Camp-Bertaux and Wyoming mont-morillonites. Clays & Clay Miner. 22: 155–165.Google Scholar
Güven, N., and Pease, R. W. 1975. Electron Optical investigations on montmorillonites-II: Morphological variations in the intermediate members of the montmorillonite-bei-dellite series. Clays & Clay Miner. 23: 187–191.Google Scholar
Harvey, C. C., and Browne, P. R. L. 1991. Mixed-layer clay geothermometry in the Wairakei geothermal field, New Zealand. Clays & Clay Miner. 39: 614–621.CrossRefGoogle Scholar
Howard, J. J., and Roy, D. M. 1985. Development of layer charge and kinetics of experimental smectite alteration. Clays & Clay Miner. 33: 81–88.Google Scholar
Hower, J., Eslinger, E. V., Hower, M. E., and Perry, E. A. 1976. Mechanism of burial metamorphism of argillaceous sediment: 1. Mineralogical and chemical evidence. Bull. Geol. Soc. Am. 87: 725–737.Google Scholar
Huang, W. L., Longo, J. M., and Pevear, D. R. 1993. An experimentally derived kinetic model for smectite-to-illite conversion and its use as a geothermometer. Clays & Clay Miner. 41: 162–177.Google Scholar
Huff, W. D., and Türkmenoglu, A. G. 1981. Chemical characteristics and origin of Ordovician K-bentonites along the Cincinnati Arch. Clays & Clay Miner. 29: 113–123.Google Scholar
Inoue, A., and Utada, M. 1983. Further investigations of a conversion series of diochahedral mica/smectites in the Shinzan hydrothermal alteration area, Northeast Japan. Clays & Clay Miner. 31: 401–412.Google Scholar
Inoue, A., Kohyama, N., Kitagawa, R., and Watanabe, T. 1987. Chemical and morphological evidence for the conversion of smectite to illite. Clays & Clay Miner. 35: 111–120.Google Scholar
Inoue, A., Velde, B., Meunier, A., and Touchard, G. 1988. Mechanism of illite formation during smectite-to-illite conversion in a hydrothermal system. Am. Miner. 73: 1305–1334.Google Scholar
Jagodzinski, H., 1949. Eindimensionale Fehlordmmg in Kristallen und ihr Einfluss auf die Rontgeninterferenzen. I. Berechnung des Fehlordnungsgrades aus der Rontgenintensitaten. Acta Crystallogr. 2: 201–207.Google Scholar
Jahren, J. S., 1991. Evidence of Ostwald ripening related recrystallization of diagenetic chlorites from reservoir rocks offshore Norway. Clay Miner. 26: 169–178.Google Scholar
Kalogeropoulos, S. I., and Mitropoulos, P. 1983. Geochemistry of barites from Milos island (Aegean Sea), Greece. N. Jb. Miner. Mh. 13–21.Google Scholar
Keller, W. D., Reynolds, R. C., and Inoue, A., 1986. Morphology of clay minerals in the smectite-to-illite conversion series by scanning electron microscopy. Clays & Clay Miner. 34: 187–197.Google Scholar
Lanson, B., and Champion, D. 1991. The I/S to illite reaction in the late stage diagenesis. Am. J. Sci. 291: 473–506.Google Scholar
Liakopoulos, A., 1987. Hydrothermalisme et mineralizations metalliferes de l' ile de Milos (Cyclades, Grece). Ph.D thesis. Univ. Pierre and Marie Curie, Paris, 276 pp.Google Scholar
Lifshitz, I. M., and Slyozov, V. V. 1961. The kinetics of precipitation from supersaturated solid solutions. J. Phys. Chem. Solids. 19: 35–50.Google Scholar
Lindgreen, H., and Hansen, P. L. 1991. Ordering of illite-smectite in Upper Jurassic claystones from the North Sea. Clay Miner. 26: 105–125.Google Scholar
Mering, J., and Oberlin, A. 1971. The smectites. In The Electron Optical Investigation of Clays. Gard, J. A., ed. Mineralogical Society: London, 193–229.Google Scholar
Muffler, P. L. J., and White, D. E. 1969. Active metamorphism of Upper Cenozoic sediments in the Salton Sea Geothermal Field and the Salton Trough, southeastern California. Bull. Geol. Soc. Am. 80: 157–182.Google Scholar
Nadeau, P. H., and Reynolds, R. C. 1981. Burial and contact metamorphism in the Mancos Shale. Clays & Clay Miner. 29: 249–259.Google Scholar
Nadeau, P. H., Tait, J. M., McHardy, W. J., and Wilson, M. J. 1984a. Interstratified XRD characteristics of physical mixtures of elementary clay particles. Clay Miner. 19: 67–76.Google Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J., and Tait, J. M. 1984b. Interstratified clays as fundamental particles. Science 225: 923–925.Google Scholar
Nadeau, P. H., Wilson, M. J., McHardy, W. J., and Tait, J. M. 1984c. Interparticle diffraction: A new concept for interstratified clays. Clay Miner. 19: 757–769.Google Scholar
Newman, A. C. D., and Brown, G. 1987. The chemical constitution of clays. In Chemistry of Clays and Clay Minerals. Newman, A. C. D., ed. London: Mineralogical Society, 1–128.Google Scholar
Ramseyer, K., and Boles, J. R. 1986. Mixed-layer illite/smectite minerals in tertiary sandstones and shales, San Joaquin Basin, California. Clays & Clay Miner. 34: 115–124.Google Scholar
Reynolds, R. C., 1989. Principles and techniques of quantitative analysis of clay minerals by X-ray powder diffraction. In Quantitative Mineral Analysis of Clays. Pevear, D. R., and Mumpton, F. A., eds. CMS workshop lectures. 1: 4–36.Google Scholar
Robertson, H. E., and Lahann, R. W. 1981. Smectite to illite conversion rates: effects of solution chemistry. Clays & Clay Miner. 29: 129–135.Google Scholar
Rosenberg, P. E., Kittrick, J. A., and Aja, S. U. 1990. Mixed layer illite/smectite: A multiphase model. Am. Miner. 75: 1182–1185.Google Scholar
Singer, A., and Staffers, P. 1980. Clay mineral diagenesis in two African lake sediments. Clay Miner. 15: 291–307.Google Scholar
Srodon, J., 1980. Precise identification of illite/smectite interstratifications by X-ray diffraction. Clays & Clay Miner. 28: 401–411.Google Scholar
Srodon, J., and Eberl, D. D. 1984. Illite. In Micas. Bailey, S. W., ed. Washington D.C.: Mineralogical Society of America, 13: 495–538.Google Scholar
Srodon, J., Morgan, D. J., Eslinger, E. V., Eberl, D. D., and Karlinger, M. R. 1986. Chemistry of illite/smectite and end-member illite. Clays & Clay Miner. 34: 368–378.Google Scholar
Srodon, J., Elsass, F., McHardy, W. J., and Morgan, D. J. 1992. Chemistry of illite-smectite inferred from TEM measurements of fundamental particles. Clay Miner. 27: 137–158.Google Scholar
Steefel, C. I., and Cappellen, P. van. 1990. A new kinetic approach to modeling water-rock interaction: The role of nucleation, precursors and Ostwald ripening. Geochim. Cosmochim. Acta 54: 2657–2677.Google Scholar
Sucha, V., Kraus, I., Gerthofferova, H., Petes, J., and Serekova, M. 1993. Smectite to illite conversion in bentonites and shales of the East Slovak Basin. Clay Miner. 28: 243–253.Google Scholar
Veblen, D. R., Guthrie, G. D. Jr., Livi, K. J. T., and Reynolds, R. C. 1990. High-resolution transmission electron microscopy and electron diffraction of mixed-layer illite smectite: Experimental results. Clays & Clay Miner. 38: 1–13.Google Scholar
Velde, B., and Nicot, E. 1986. Diagenetic clay mineral composition as a function of pressure, temperature and chemical activity. J. Sed. Pet. 55: 541–547.Google Scholar
Whitney, G., 1990. Role of water in the smectite-to-illite reaction. Clays & Clay Miner. 38: 343–350.Google Scholar
Whitney, G., and Northrop, R. 1988. Experimental investigation of the smectite to illite reaction: Dual reaction mechanisms and oxygen-isotope systematics. Am. Miner. 73: 77–90.Google Scholar