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Experimental Alteration of Volcanic Tuff: Smectite Formation and Effect on 18O Isotope Composition

Published online by Cambridge University Press:  28 February 2024

Javier Cuadros*
Affiliation:
Departamento de Ciencias de la Tierra y Química Ambiental, Estación Experimental del Zaidín, Profesor Albareda 1, E-18008 Granada, Spain
Emilia Caballero
Affiliation:
Departamento de Ciencias de la Tierra y Química Ambiental, Estación Experimental del Zaidín, Profesor Albareda 1, E-18008 Granada, Spain
F. Javier Huertas
Affiliation:
Departamento de Ciencias de la Tierra y Química Ambiental, Estación Experimental del Zaidín, Profesor Albareda 1, E-18008 Granada, Spain
Concepción Jiménez de Cisneros
Affiliation:
Departamento de Ciencias de la Tierra y Química Ambiental, Estación Experimental del Zaidín, Profesor Albareda 1, E-18008 Granada, Spain
Francisco Huertas
Affiliation:
Departamento de Ciencias de la Tierra y Química Ambiental, Estación Experimental del Zaidín, Profesor Albareda 1, E-18008 Granada, Spain
José Linares
Affiliation:
Departamento de Ciencias de la Tierra y Química Ambiental, Estación Experimental del Zaidín, Profesor Albareda 1, E-18008 Granada, Spain
*
E-mail of corresponding author: [email protected]
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Abstract

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Three samples of volcanic tuff were hydrothermally altered at ∼82°C in a soxhlet apparatus for periods from 745 to 2706 h. The samples correspond to partially altered specimens of volcanic tuff with 6 wt. % (T3a) and 9 wt. % (T3b) smectite and to the calcination product of the latter (T3c). The calcination treatment melted the smectite in the sample. Untreated samples and alteration products were studied by X-ray diffraction (XRD), differential thermal analysis (DTA) and thermogravimetry (TG), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, and oxygen isotope analysis. DTA-TG of the <2-µm size fractions showed that there was a small increase of smectite relative to glass after alteration for samples T3a and T3b, with the amount of smectite increasing exponentially with time. No smectite formed in sample T3c. These results suggest that smectite acts as a nucleation site for the precipitation of new smectite. The amount of glass in the <2-µm size fraction increased, although slightly decreased relative to smectite. SEM-EDX analysis showed smectite with the approximate structural formula of Na0.22K0.08Mg0.12Ca0.03VI(Al1.47Fe0.05Mg0.48)IV(Si3.97Al0.03)O10(OH)2.

Oxygen isotope composition of the <2-µm size fraction became enriched in 18O by alteration, the >2-µm size fraction of T3b did not vary, and that of T3c was depleted in 18O. Our results are consistent with three processes during alteration: 1) oxygen isotope exchange between volcanic glass and water, 2) neoformation of smectite, and 3) hydration and consequent hydroxylation of the calcined glass.

Type
Research Article
Copyright
Copyright © 1999, The Clay Minerals Society

References

Bechtel, A. and Hoernes, S., 1990 Oxygen isotope fractionation between oxygen on different sites in illite minerals: A potential single-mineral thermometer Contributions to Mineralogy and Petrology 104 463470 10.1007/BF01575623.CrossRefGoogle Scholar
Berkgaut, V. Singer, A. and Stahr, K., 1994 Palagonite reconsidered: Paracrystalline illite-smectites from regoliths on basic pyroclastics Clays and Clay Minerals 42 582592 10.1346/CCMN.1994.0420511.CrossRefGoogle Scholar
Borthwick, J. and Harmon, R., 1982 A note regarding ClF3 as an alternative to BrF5 for oxygen isotope analysis Geo-chimica et Cosmochimica Acta 46 16651668 10.1016/0016-7037(82)90321-0.CrossRefGoogle Scholar
Caballero, E. Reyes, E. Delgado, A. Huertas, E. and Linares, J., 1992 The formation of bentonite: Mass balance effects Applied Clay Science 6 265276 10.1016/S0169-1317(09)90002-3.CrossRefGoogle Scholar
Cerling, T. Brown, E. and Bowman, J., 1985 Low-temperature alteration of volcanic glass: Hydration, Na, K, l8O and Ar mobility Chemical Geology 52 281293.Google Scholar
Cole, D.R. Ohmoto, H., Valey, J.W. Taylor, H.P. and O’Neil, J.R., 1986 Kinetics of isotopic exchange at elevated temperatures and pressures Stable Isotopes in High Temperature Geological Processes, Reviews in Mineralogy, Volume 16 Washington, D.C. Mineralogical Society of America 4190 10.1515/9781501508936-007.CrossRefGoogle Scholar
Crovisier, J.-L. Honnorez, J. and Fritz, B., 1992 Dissolution of subglacial glasses from Iceland: Laboratory study and modelling Applied Geochemistry 1 5581 10.1016/S0883-2927(09)80064-4.CrossRefGoogle Scholar
Cuadros, J. Huertas, F. Delgado, A. and Linares, J., 1994 Determination of hydration (H2O) and structural (H2O+) water for chemical analysis of smectites. Application to Los Trancos smectites, Spain Clay Minerals 29 297300 10.1180/claymin.1994.029.2.16.CrossRefGoogle Scholar
Epstein, S. and Mayeda, T.K., 1953 Variation of the 18O/16O ratio in natural waters Geochimica et Cosmochimica Acta 4 213224 10.1016/0016-7037(53)90051-9.CrossRefGoogle Scholar
Giletti, B.J., 1985 The nature of oxygen transport within minerals in the presence of hydrothermal water and the role of diffusion Chemical Geology 53 197206 10.1016/0009-2541(85)90069-5.CrossRefGoogle Scholar
Hoeffs, J., 1980 Stable Isotope Geochemistry Berlin Springer-Verlag 10.1007/978-3-662-02290-0.CrossRefGoogle Scholar
James, A.T. and Baker, D.R., 1976 Oxygen isotope exchange between illite and water at 22Å°C Geochimica et Cosmochimica Acta 40 235239 10.1016/0016-7037(76)90180-0.CrossRefGoogle Scholar
Kawano, M. and Tomita, K., 1992 Formation of allophane and beidellite during hydrothermal alteration of volcanic glass below 200Å°C Clays and Clay Minerals 40 666674 10.1346/CCMN.1992.0400606.CrossRefGoogle Scholar
Kawano, M. Tomita, K. and Kamino, Y., 1993 Formation of clay minerals during low temperature experimental alteration of obsidian Clays and Clay Minerals 41 431441 10.1346/CCMN.1993.0410404.CrossRefGoogle Scholar
Linares, J., 1987 Isotope exchange in phyllosilicates after their formation. II Spanish Meeting on Geochemistry, Soria, Spain 5562 (in Spanish).Google Scholar
Lopez, J. and Rodriguez, E., 1980 The Neogene volcanic region in south-eastern Spain Estudios Geológicos 36 563 (in Spanish).Google Scholar
Newman, A. Brown, G. and Newman, A.C.D., 1987 The chemical constitution of clays Chemistry of Clays and Clay Minerals London Mineralogical Society 1128.Google Scholar
O’Neil, J.R. and Kharaka, Y.K., 1976 Hydrogen and oxygen isotope exchange reactions between clay minerals and water Geochimica et Cosmochimica Acta 40 241246 10.1016/0016-7037(76)90181-2.CrossRefGoogle Scholar
Savin, S., Fritz, P. and Fontes, J.C., 1980 Oxygen and hydrogen isotope effects in low-temperature mineral-water interactions Handbook of Environmental Isotope Geochemistry, Volume 1 Amsterdam Elsevier 283328.Google Scholar
Savin, S.M. and Epstein, S., 1970 The oxygen and hydrogen isotope geochemistry of clay minerals Geochimica et Cosmochimica Acta 34 2542 10.1016/0016-7037(70)90149-3.CrossRefGoogle Scholar
Savin, S.M. and Epstein, S., 1970 The oxygen and hydrogen isotope geochemistry of ocean sediments and shales Geochimica et Cosmochimica Acta 34 4363 10.1016/0016-7037(70)90150-X.CrossRefGoogle Scholar
Schultz, L., 1969 Lithium and potassium absorption, dehydroxylation temperature, and structural water content of aluminous smectites Clays and Clay Minerals 17 115149 10.1346/CCMN.1969.0170302.CrossRefGoogle Scholar
Shapiro, L., 1975 Rapid analysis of silicate, carbonate, and phosphate rocks-revised edition United States Geological Survey Bulletin 1401 Washington, D.C. United States Government Printing Office.Google Scholar
Tazaki, K. Fyfe, W.S. and van der Gaast, S.J., 1989 Growth of clay minerals in natural and synthetic glasses Clays and Clay Minerals 37 348354 10.1346/CCMN.1989.0370408.CrossRefGoogle Scholar
Tazaki, K. Tiba, T. Aratani, M. and Miyachi, M., 1992 Structural water in volcanic glass Clays and Clay Minerals 40 122127 10.1346/CCMN.1992.0400113.CrossRefGoogle Scholar
Thomassin, J. Boutonnat, F. Touray, J. and Baillif, P., 1989 Geochemical role of the water/rock ratio during the experimental alteration of a synthetic basaltic glass at 50Å°C. An XPS and STEM investigation European Jornal of Mineralogy 1 261274 10.1127/ejm/1/2/0261.CrossRefGoogle Scholar
Tomita, K Y H and Kawano, M., 1993 Synthesis of smectite from volcanic glass at low temperature Clays and Clay Minerals 41 655661 10.1346/CCMN.1993.0410603.CrossRefGoogle Scholar
van Zevenbergen, C. Reeuwijk, L. Bradley, J. Bloemen, P. and Comans, R., 1996 Mechanism and conditions of clay formation during natural weathering of MSWI bottom ash Clays and Clay Minerals 44 546552 10.1346/CCMN.1996.0440414.CrossRefGoogle Scholar