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Structure and Growth Mechanism of Glauconite as Seen by High-Resolution Transmission Electron Microscopy

Published online by Cambridge University Press:  02 April 2024

Marc Amouric  and
Claude Parron
Marc Amouric
Affiliation:
Centre de Recherche sur les Mécanismes de la Croissance Cristalline CNRS-Campus de Luminy, Case 913, 13288 Marseille cedex 09, France
Claude Parron
Affiliation:
Laboratoire de Géologie Dynamique et Laboratoire associé au CNRS no. 132, Faculté des Sciences Saint-Jérôme, 13397 Marseille cedex 13, France
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Abstract

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The internal fabric of glauconite pellets has been studied by high-resolution transmission electron microscopy (HRTEM) for a better understanding of the glauconitization process. Typical “lamellae” which make up the glauconite pellets showed a spindle-like arrangement of layered crystallite packets. Three main mineral phases were detected: (1) well-ordered glauconite sensu stricto (d(001) = 10 Å) generally in the middle of the spindles; (2) a poorly ordered and undetermined layered-phase “X” with d(001) ~ 12.5 Å, usually sandwiching glauconite such that the interface between the two materials is very sharp; and (3) a noncrystalline or gel-like phase located between the lamellae. A 14-Å smectite-like phase was rarely observed at the periphery of some grains. The glauconite crystallites clearly showed characteristic growth features (e.g., growth steps), whereas the unknown phase X exhibited destabilization characteristics. A structural analysis of the pure glauconite indicates that this dioctahedral mica was present in the IMd (disordered), 1M, and, to a much lesser extent, 2M1 polytypic forms. HRTEM revealed no interlayering of glauconite with the other layered phases. Rather, it appeared to have formed by a layer-growth mechanism at the expense of the unknown phase X which apparently converted into non-crystalline matter before converting to glauconite. The precursor function of the interlamellae “gel” phase during the evolutive process of glauconitization is not understood.

Résumé

Résumé

La structure interne de grains de glauconie provenant de roches sédimentaires paléocènes de Côte d'Ivoire, a été étudiée par la microscopie électronique en transmission à haute résolution (METHR) afin de mieux comprendre le processus de glauconitogenèse. Les lamelles typiques, observées au microscope électronique à balayage, qui composent la glauconite, révèlent en METHR une organisation en fuseaux ou navettes constitués de paquets de cristallites à structure en feuillets. Trois phases principales ont pu être détectées: (1) La glauconite s.S. bien ordonnée (d(001) = 10 Å) au coeur des fuseaux; (2) une phase mal ordonnée et indéterminée (phase X), telle que (d(001) ~ 12,5 Å), entoure communément les paquets de cristallites de glauconite; et (3) une phase non cristallisée, ressemblant à un gel, localisée entre les lamelles. Une phase à 14 Å de type smectitique a pu être rarement observée à la périphérie de certains grains.

L'analyse structurale des cristallites de glauconite indique que ce mica dioctaédrique présente le plus souvent les formes polytypiques 1M et 1Md et moins fréquemment la forme 2M1, mise en évidence ici pour la première fois. Concernant les relations entre les différentes phases observées, la METHR ne révèle aucune interstratification des feuillets de glauconite avec les autres phases. Les cristallites de glauconite montrent clairement des figures caractéristiques de croissance (gradins par exemple) aux endroits ou la phase X présente des caractères de déstabilisation, tels que sa transformation en un matériau pauvrement cristallisé ou amorphe. Ainsi l’étude en METHR des grains de glauconie révèle que la glauconitisation constitue un processus évolutif au cours duquel le premier stade cristallisé semble représenter par la formation, peut être à partir d'un gel, d'une phase X en feuillets à 12,5 Å (smectite Fe ou nontronite?). La cristallisation de la phase glauconitique, par un mécanisme de croissance par couches, suit la déstabilisation (amorphisation) de la phase à 12,5 Å. Ces nouvelles observations militent fortement pour la théorie de la néoformation de la glauconite plutôt que pour la “layer-lattice theory”.

Keywords

GlauconiteGrowth mechanismHigh-resolution transmission electron microscopyMicaPolytype
Type
Research Article
Information
Clays and Clay Minerals , Volume 33 , Issue 6 , December 1985 , pp. 473 - 482
Copyright
Copyright © 1985, The Clay Minerals Society

References

Amouric, M. and Baronnet, A., 1983 Effect of early nu-cleation conditions on synthetic muscovite polytypism as seen by high resolution transmission electron microscopy Phys. Chem. Miner. 9 146–159.CrossRefGoogle Scholar
Amouric, M., Baronnet, A. and Finck, C., 1978 Polyty-pisme et désordre dans les micas dioctaédriques synthétiques. Etude par imagerie de réseau Mat. Res. Bull. 13 627–634.CrossRefGoogle Scholar
Amouric, M., Mercuriot, G. and Baronnet, A., 1981 On computed and observed HRTEM images of perfect mica polytypes Bull. Mineral. 104 298–313.Google Scholar
Appelo, C. A. J., 1978 Aspects of mica-related clay minerals in hydrogeochemistry Univ. Amsterdam Ph.D. thesis.Google Scholar
Baronnet, A., 1974 Etude en microscopie électronique des premiers stades de croissance d’un mica synthétique, la phlogopite hydroxylée High Temp. High Press. 6 193–198.Google Scholar
Baronnet, A., Amouric, M. and Chabot, B., 1976 Mécanismes de croissance, polytypisme et polymorphisme de la musco vite hydroxylée synthétique J. Cryst. Growth 32 37–59.CrossRefGoogle Scholar
Bentor, Y. K. and Kastner, M., 1965 Notes on the mineralogy and origin of glauconite J. Sed. Petrol. 35 155–166.Google Scholar
Burst, J. F., 1958 Mineralogical heterogeneity in “glauconite” pellets Amer. Mineral. 43 481–497.Google Scholar
Burst, J. F., 1958 “Glauconite” pellets: their mineral nature and applications to stratigraphie interpretations Bull. Amer. Assoc. Pet. Geol. 42 310–327.Google Scholar
Charpy, N. and Nahon, D. (1978) Contribution à l’étude lithostratigraphique et chronostratigraphique du Tertiaire du Bassin de Côte d’Ivoire: Rapp. Dêp. Se. Terre, Univ. Abidjian 18, 33 pp.Google Scholar
Cimbâlnikovâ, A., 1971 Chemical variability and structural heterogeneity of glauconites Amer. Minerai. 56 1385–1392.Google Scholar
Cimbâlnikovâ, A., 1971 Influence of 10 Å-14 Å inter-layering on the layer charge of glauconites Amer. Minerai. 56 1393–1398.Google Scholar
De Gennes, P. G., 1974 The Physics of Liquid Crystals Oxford Oxford Univ. Press.Google Scholar
Eberhart, J. P. and Triki, R., 1972 Description d’une technique permettant d’obtenir des coupes minces de minéraux argileux par ultramicrotomie. Application à l’étude des minéraux argileux interstratifiés J. Microscop. 15 111–120.Google Scholar
Ernst, W. G., 1963 Significance of phengitic micas from low-grade schists Amer. Mineral. 48 1357–1373.Google Scholar
Giresse, P. and Odin, G. S., 1973 Nature minéralogique et origine des glaucomes du plateau continental du Gabon et du Congo Sedimentology 20 457–488.CrossRefGoogle Scholar
Hower, J., 1961 Some factors concerning the nature and origin of glauconite Amer. Mineral. 46 313–334.Google Scholar
Iijima, S. and Buseck, P. R., 1978 Experimental study of disordered mica structure by HREM Acta Crystallogr. A34 709–719.CrossRefGoogle Scholar
Katsnel’son, Y.Y., Nyrkov, A.A. and Yakushev, V.V., 1978 Structural and chemical characteristics of glauconite as its qualitative indicators Lithol. Min. Res. 13 324–335.Google Scholar
Köhler, E. E., 1980 The occurrence and properties of glauconites in Mesozoic and Cenozoic sediments in northwestern and southern Germany Geol. Jb. D39 115–136.Google Scholar
McRae, S. G., 1972 Glauconite Earth-Sci. Rev. 8 397–440.CrossRefGoogle Scholar
McRae, S. G. and Lambert, J. L. M., 1968 A study of some glauconites from Cretaceous and Tertiary formations in southeast England Clay Mineral. 7 431–440.CrossRefGoogle Scholar
Manghnani, M. H. and Hower, J., 1964 Glauconites: cation exchange capacities and infrared spectra Amer. Mineral. 49 586–598.Google Scholar
Martin, L., 1972 Etude des “faecal-pellets” minéralisés des sédiments du plateau continental de Côte d’Ivoire Cah. ORSTOM, sér. Géol. 4 105–120.Google Scholar
Nahon, D., Carozzi, A. V. and Parron, C., 1980 Lateritic weathering as a mechanism for the generation of ferruginous ooïds J. Sed. Petrol. 50 1287–1298.Google Scholar
Odin, G. S., 1974 Application de la microscopie électronique par réflexion à l’étude des minéraux argileux: exemple des minéraux des glauconies Trav. Lab. Micropal, Univ. Paris 3 297–313.Google Scholar
Odin, G. S., 1975 Les glauconies: constitution, formation, âge Paris Ph.D. thesis, Univ..Google Scholar
Odom, I. E., 1976 Microstructure, mineralogy and chemistry of Cambrian galuconite pellets and glauconite, central U.S.A. Clays & Clay Minerals 24 232–238.CrossRefGoogle Scholar
Oertel, G., Curtis, C. D. and Phakey, P. P., 1973 A transmission electron microscope and X-ray diffraction study in muscovite and chlorite Mineral. Mag. 39 176–188.CrossRefGoogle Scholar
Parron, C. and Nahon, D., 1980 Red bed genesis by lateritic weathering of glauconitic sediments J. Geol. Soc. London 137 689–693.CrossRefGoogle Scholar
Paulus, M., Dubon, A. and Etienne, J., 1975 Application of ion thinning to the study of the structure of argillaceous rocks by transmission electron microscopy Clays & Clay Minerals 20 193–197.Google Scholar
Phakey, P. P., Curtis, C. D. and Oertel, G., 1972 Transmission electron microscopy of fine-grained phyllosilicates in ultra-thin rock sections Clays & Clay Minerals 20 193–197.CrossRefGoogle Scholar
Porrenga, D. H., 1967 Glauconite and chamosite as depth indicators in the marine environment Marine Geol. 5 495–501.CrossRefGoogle Scholar
Tchoubar, C., Rautureau, M. and Clinard, C., 1973 Technique d’inclusion appliquée à l’étude des silicates lamellaires et fibreaux J. Microsc. 18 147–157.Google Scholar
Thompson, G. R. and Hower, J., 1975 The mineralogy of glauconite Clays & Clay Minerals 23 289–300.CrossRefGoogle Scholar
Velde, B., 1976 The chemical evolution of glauconite pellets as seen by microprobe determinations Mineral. Mag. 40 753–760.CrossRefGoogle Scholar
Velde, B. and Odin, G.S., 1975 Further information related to the origin of glauconite Clays & Clay Minerals 23 376–381.CrossRefGoogle Scholar
Warshaw, C. M., 1957 The mineralogy of glauconite: Ph.D. thesis, Pennsylvania State Univ. Pennsylvania University Park.Google Scholar
Wermund, E. G., 1961 Glauconite in early Tertiary sediments of Gulf Coastal Province Bull. Amer. Assoc. Pet. Geol. 45 1667–1696.Google Scholar
Wise, W. S. and Eugster, H. P., 1964 Celadonite: synthesis, thermal stability and occurrence Amer. Mineral. 49 1031–1083.Google Scholar
Yoder, H. S. and Eugster, H. P., 1955 Synthetic and natural muscovites Geochim. Cosmochim. Acta 8 225–280.CrossRefGoogle Scholar