Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-27T08:20:20.337Z Has data issue: false hasContentIssue false
  • English
  • Français

Paramagnetic Defect Centers in Hydrothermal Kaolinite from an Altered Tuff in the Nopal Uranium Deposit, Chihuahua, Mexico

Published online by Cambridge University Press:  02 April 2024

Jean-Pierre Muller ,
Philippe Ildefonse  and
Georges Calas
Jean-Pierre Muller
Affiliation:
O.R.S.T.O.M., Département T.O.A., 75480 Paris Cedex 10, France Laboratoire de Minéralogie-Cristallographie, UA CNRS 09, Universités Paris 6 et 7, 4 Place Jussieu, 75252 Paris Cedex 05, France
Philippe Ildefonse
Affiliation:
U.F.R. Sciences Physiques de la Terre, Université Paris 7, 2 Place Jussieu, 75251 Paris Cedex 05, France Laboratoire de Minéralogie-Cristallographie, UA CNRS 09, Universités Paris 6 et 7, 4 Place Jussieu, 75252 Paris Cedex 05, France
Georges Calas
Affiliation:
Laboratoire de Minéralogie-Cristallographie, UA CNRS 09, Universités Paris 6 et 7, 4 Place Jussieu, 75252 Paris Cedex 05, France
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Point defect centers in hydrothermal kaolinite have been investigated using electron paramagnetic resonance (EPR). Kaolinite was sampled in petrographically well-defined materials coming from uranium-rich hydrothermally altered volcanic tuffs (Nopal I uranium deposit, Chihuahua, Mexico), which show extensive kaolinization and an intense redistribution of uranium. Several kaolinite parageneses were defined according to their origin (fissure fillings and feldspar pseudomorphs); their location relative to the U6+ mineralization at the scale of the deposit (mineralized breccia pipe vs. barren surrounding rhyolitic tuffs), and at the scale of mineral assemblages; and their crystal chemistry.

Two types of centers of axial symmetry were identified (A- and A′-centers) and represent positive holes trapped on apical oxygens (Si-O−-centers). A-centers were stable to 400°C, whereas A′-centers annealed at 350°C. A relation between defect-center concentration and U content demonstrates that natural irradiation was responsible for these centers. On the other hand, defect-center concentration was not directly linked to the origin (fissural or feldspar pseudomorph) or the crystal chemistry (structural order and substitutional Fe3+ content) of the kaolinite. According to petrographic data, and with respect to the relative thermal stability of A- and A′-centers, two successive irradiations of kaolinite were evidenced: (1) originally during crystallization of kaolinite from radioactive hydrothermal solutions, and (2) permanently when kaolinite was in contact with secondary U-silicates, which led to the formation of A′-centers.

Because of the short half-life of U, these two radiation-induced centers were created by short-lived elements of the U-decay series. As a consequence, variations of defect-center concentration possibly reflect variations in radioactive disequilibrium during the history of the alteration system. This provides a unique tool for tracing the dynamics of the transfer of radionuclides in the geosphere: kaolinite may be used as a sensitive in situ dosimeter, which may be useful in the fields of weathering petrology and nuclear waste management.

Keywords

Defect centersElectron paramagnetic resonanceHydrothermalKaoliniteNatural radiation
Type
Research Article
Information
Clays and Clay Minerals , Volume 38 , Issue 6 , December 1990 , pp. 600 - 608
Copyright
Copyright © 1990, The Clay Minerals Society

References

Alba, L. A. and Chavez, R., 1974 K-Ar ages from volcanic rocks from the Central Peña Blanca, Chihuahua, Mexico Isochron West 10 21 – 23.Google Scholar
Angel, B. R., Jones, J. P. E. and Hall, P. L., 1974 Electron paramagnetic resonance studies of doped synthetic kaolinite. I Clay Miner 10 247 – 255.CrossRefGoogle Scholar
Aniel, B. (1983) Les gisements uranifères associés au volcanisme acide Tertiaire de la Sierra Peña Blanca (Chihuahua, Mexique): Geol. Geochim. Uranium Mem. 2, C.R.E.G.U., Nancy, France, 291 pp.Google Scholar
Calas, G., 1977 Les phénomènes d’altération hydrothermale et leur relation avec les mineralisations uranifères en milieu volcanique; le cas des ignimbrites tertiaires de la Sierra Peña Blanca, Chihuahua, Mexique Sci. Geol. Bull. 30 3 – 18.CrossRefGoogle Scholar
Calas, G., 1988 Electron paramagnetic resonance Spectroscopic Methods in Mineralogy and Geology, Reviews in Mineralogy 18 513 – 571.CrossRefGoogle Scholar
Cardenas-Flores, D., 1985 Volcanic stratigraphy and U-Mo mineralization of the Sierra Peña Blanca district, Chihuahua, Mexico Proc. Technical Committee Meeting on Uranium Deposits in Volcanic Rocks, El Paso, Texas, 1984 Vienna I.A.E.A. 125 – 136.Google Scholar
Cases, J. M., Lietard, O., Yvon, J. and Delon, J. F., 1982 Etude des proprietes cristallographiques, morphologiques, superficielles de kaolinites désordonnées Bull. Mineral. 105 439 – 455.Google Scholar
Chaulot-Talmon, J. F., 1984 Etude géologique et structurale des ignimbrites du tertiaire de la Sierra Madre Occidentale, entre Hermosillo et Chihuahua, Mexique .Google Scholar
Clozel, B., Muller, J. P., Dran, J. C., Hervé, J. and Calas, G., 1989 Study of alteration systems in the light of nuclear waste repository, 3. Radiation efficiency and dose rate estimation Proc. E.U.G. V Congress, Strasbourg, 1989, Terra Abstr. 1 112.Google Scholar
Cortes, M. R., Cruz, R. B. and Guerrero, S. P. (1980) Description petrografica de las mustras obtenidas de los nivelos cero y cuaranta del yacimineto Nopal I, Sierra Peña Blanca, municipio de Aldama, Chihuahua: in Uramex Intern. Report, Informe 10/80, URAMEX, Mexico, 67 pp.Google Scholar
De Endredy, A. S., 1963 Estimation of free iron oxides in soils and clays by a photolytic method Clay Miner 5 209 – 217.CrossRefGoogle Scholar
George-Aniel, B., Leroy, J. and Poty, B., 1985 Uranium deposits of the Sierra Peña Blanca, three examples of mechanisms of ore deposit formation in a volcanic environment Proc. Technical Committee Meeting on Uranium Deposits in Volcanic Rocks, El Paso, Texas, 1984 Vienna I.A.E.A. 175 – 186.Google Scholar
Giese, R. F., 1988 Kaolin minerals. Structures and stabilities Hydrous Phyllosilicates, Reviews in Mineralogy 19 29 – 66.CrossRefGoogle Scholar
Goodell, P. C., 1981 Geology of the Peña Blanca uranium deposit, Chihuahua, Mexico Uranium in Volcanic and Volcaniclastic Rocks 13 275 – 291.Google Scholar
Govindaraju, K., 1973 New scheme of silicate analysis (16 major, minor and trace elements) based mainly on ion exchange dissolution and emission spectrometry method Analysis 2 367 – 376.Google Scholar
Hall, P. L., 1980 The application of electron spin resonance to studies of clay minerals. Isomorphous substitution and external surface properties Clay Miner 15 321 – 335.CrossRefGoogle Scholar
Ildefonse, P.h. Muller, J. P., Cesbron, F. and Sichère, M. C., 1988 Mineralogy of uranium concentrations and associated hydrothermal alteration minerals in ignimbritic tuffs, Sierra Peña Blanca, Chihuahua, Mexico Geol. Soc. Amer. Abs. Progrs. 20 7.Google Scholar
Ildefonse, P.h. Cesbron, F., Muller, J. P. and Calas, G., 1989 Study of alteration systems in the light of nuclear waste repository safety. 1. Element remobilization in hydrothermally altered tuffs Proc. E. U. G. V Congress, Strasbourg, 1989, Terra Abstr. 1 111 – 112.Google Scholar
Ildefonse, P.h. Muller, J. P., Clozel, B. and Calas, G., 1990 Study of two alteration systems as natural analogues for radionuclide release and migration Eng. Geol. .CrossRefGoogle Scholar
Keller, W. D., 1976 Scan electron micrographs of kaolins collected from diverse environments or origin, I and II Clays & Clay Minerals 24 107 – 117.CrossRefGoogle Scholar
Leroy, J. L., Aniel, B. and Poty, B., 1987 The Sierra Peña Blanca (Mexico) and the Meseta Los Frailes (Bolivia): The uranium concentration mechanisms in volcanic environment during hydrothermal processes Uranium 3 211 – 234.Google Scholar
Magonthier, M. C. (1984) Les ignimbrites de la Sierra Madre Occidentale et de la province uranifère de la Sierra Peña Blanca, Mexique: Mem. Sci Terre 84–17, Univ. Paris VI, Paris, 351 pp.Google Scholar
Magonthier, M. C., 1987 Relations entre les minéralisations d’uranium de la Sierra Peña Blanca (Mexique) et les ignimbrites porteuses Bull. Minéral. 110 305 – 317.CrossRefGoogle Scholar
Marfunin, A. S., 1979 Spectroscopy, Luminescence and Radiation Centers in Minerals Berlin Springer-Verlag.CrossRefGoogle Scholar
Meads, R. E. and Maiden, P. J., 1975 Electron spin resonance in natural kaolinites containing Fe3+ and other transition metal ions Clay Miner 10 313 – 345.CrossRefGoogle Scholar
Mestdagh, M. M., Vielvoye, L. and Herbillon, A. J., 1980 Iron in kaolinite, II. The relationships between kaolinite crystallinity and iron content Clay Miner 15 1 – 14.CrossRefGoogle Scholar
Muller, J. P. (1988) Analyse petrologique d’une formation lateritique meuble du Cameroun. Essai de traçage d’une différentiation supergène par les paragénèses minérales secondares: Travaux et Documents Microfichés 50, ORSTOM, Paris, 664 pp.Google Scholar
Muller, J. P., Bocquier, G., Schultz, L. G., van Olphen, H. and Mumpton, F. A., 1987 Textural and mineralogical relationships between ferruginous nodules and surrounding clayey matrices in a laterite from Cameroon Proc. Int. Clay Conf., Denver, 1985 Bloomington, Indiana The Clay Minerals Society 186 – 196.Google Scholar
Muller, J. P. and Calas, G., 1989 Tracing kaolinites through their defect centers; kaolinite paragenesis in a laterite (Cameroon) Econ. Geol. 84 694 – 707.CrossRefGoogle Scholar