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Textural Transition and Genetic Relationship between Precursor Stevensite and Sepiolite in Lacustrine Sediments (Jbel Rhassoul, Morocco)

Published online by Cambridge University Press:  28 February 2024

Azeddine Chahi ,
Bertrand Fritz ,
Joelle Duplay ,
Francis Weber  and
Jacques Lucas
Azeddine Chahi
Affiliation:
Centre de Géochimie de la Surface, CNRS, 1, rue Blessig, 67084 Strasbourg Cedex, France Faculté des Sciences Semlalia, Boulevard Amir Moulay Abdellah, BP S.15 Marrakech, Maroc
Bertrand Fritz
Affiliation:
Centre de Géochimie de la Surface, CNRS, 1, rue Blessig, 67084 Strasbourg Cedex, France
Joelle Duplay
Affiliation:
Centre de Géochimie de la Surface, CNRS, 1, rue Blessig, 67084 Strasbourg Cedex, France
Francis Weber
Affiliation:
Centre de Géochimie de la Surface, CNRS, 1, rue Blessig, 67084 Strasbourg Cedex, France
Jacques Lucas
Affiliation:
Centre de Géochimie de la Surface, CNRS, 1, rue Blessig, 67084 Strasbourg Cedex, France Université Louis Pasteur, Institut des Sciences de la terre, 1, rue Blessig, 67084 Strasbourg Cedex, France
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Abstract

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In the Tertiary lacustrine sediments of the Jbel Rhassoul (Morocco), stevensite and sepiolite, confined to the dolomitic facies, are commonly mixed at lower parts of the so-called “Formation Intermédiaire”. Transmission electron microscopy (TEM) observations reveal a relation between these 2 magnesian clay minerals. One can observe the different transition steps, from the initial folded layers of stevensite to the fibers emerging from the layers, and finally to the complete replacement of stevensite by sepiolite. That transition can also be observed by scanning electron microscopy (SEM), where the fibers seem to grow at the expense of stevensite. Thermodynamic calculations have been applied to provide geochemical conditions for the formation of sepiolite after stevensite. Early deposition of the “Formation Intermédiaire” occurred under climatic conditions varying between dry and wet. During dry periods, the relative silica enrichment and the pH decrease in the lake water should destabilize stevensite, leading to the formation of sepiolite. Subsequently, a perennial wet climate would lead to the formation of pure stevensite without any trace of sepiolite.

Keywords

Jbel RhassoulSepioliteStevensiteTextural TransitionThermodynamic Calculation
Type
Research Article
Information
Clays and Clay Minerals , Volume 45 , Issue 3 , June 1997 , pp. 378 - 389
Copyright
Copyright © 1997, The Clay Minerals Society

References

Ais, M., (1984) Etude géologique du gisement de rhassoul de Tamdafelt (bassin de Missour) [M.S. Thesis] Fes, Morocco Univ Sidi Mohamed Ben Abdelah..Google Scholar
Badaut, D. and Risacher, F., (1983) Authigenic smectite on diatom frustules in Bolivian saline lakes Geochim Cosmochim Acta 47 47–375 10.1016/0016-7037(83)90259-4.CrossRefGoogle Scholar
Badaut, D. Risacher, F. Paquet, H. Eberhart, J.R. and Weber, F., (1979) Néoformation de minéraux argileux à partir de frustules de diatomées: le cas des lacs de l’Altiplano bolivien CR Acad Sci Paris, Ser D 289 1191–1193.Google Scholar
Brauner, K. and Preisinger, A., (1956) Struktur und Entschung des sepioliths Tschermaks Min Petr Mitt 6 6–140 10.1007/BF01128033.CrossRefGoogle Scholar
Caillère, S. Henin, S. and Rautureau, M., (1982) Minéralogie des argiles Paris Masson.Google Scholar
Chahi, A., (1988) Recherche de quelques méthodes de purification des minéraux argileux. Etude cristallochimique de quelques echantillons du Jbel Rhassoul [M.S. thesis] Strasbourg, France Univ Louis Pasteur.Google Scholar
Chahi, A., (1992) Comparaison des minéraux argileux des formations lacustres du Jbel Rhassoul et des phosphorites marines des Ganntour au Maroc Strasbourg, France Univ Louis Pasteur.Google Scholar
Chahi, A., (1996) Les minéraux argileux des gisements de phosphorites des Ganntour et de stévensite du Jbel Rhassoul (Maroc): relations génétiques entre les argiles 2:1 et les argiles fibreuses en conditions de surface [thèse de doctorat d’état es., sciences] Marrakech Univ Cadi Ayyad.Google Scholar
Chahi, A. Duplay, J. and Lucas, J., (1993) Analyses of palygorskite and associated clays from the Jbel Rhassoul (Morocco): Chemical characteristics and origin of formation Clays Clay Miner 41 41–411 10.1346/CCMN.1993.0410401.CrossRefGoogle Scholar
Chahi, A. Risacher, F. Ais, M. Duringer, P., Karaka, Y.K. and Maest, A.S., (1992) Diagenetic stevensite after dolomite in lacustrine deposit of Jbel Rhassoul (Morocco) Proc Int Symp water rock interaction: Park City, UT Rotterdam Balkema 627–629.Google Scholar
Chahi, A. Weber, F. Prévôt, L. and Lucas, J., (1993) L’utilisation des résines échangeuses de cations (Amberlite IRC-50H) dans la dispersion et la purification des roches à carbonates, phosphates et sulfates Clay Miner 28 585–601 10.1180/claymin.1993.028.4.08.CrossRefGoogle Scholar
Cliff, G. and Lorimer, G.W., (1975) The quantitative analysis of thin specimens J Microsc 103 103–207 10.1111/j.1365-2818.1975.tb03895.x.CrossRefGoogle Scholar
Doval, M. Rautureau, M. Brell, J.M. Fontaine, C., Galan, E. Perez-Rodriguez, J. and Cornejo, J., (1987) Cristalchemistry of “pink clays” from the Tertiary Madrid Basin. Its relationship with the sepiolite occurrence Proc 6th Meet Euro Clay Groups 203–204.Google Scholar
Duplay, J., (1988) Géochimie des argiles et géothermométrie des populations monominérales de particules [thèse de doctorat d’état es., sciences] Strasbourg Univ Louis Pasteur.Google Scholar
Duringer, P. Ais, M. and Chahi, A., (1995) Contexte géodynamique et milieu de dépôt du gisement de stévensite (rhassoul) miocène du Maroc: Environnement lacustre ou évaporitique? Bull Soc Geol Fr 166 169–179.Google Scholar
Fritz, B. 1981. Etude thermodynamique et modélisation des reactions hydrothermales et diagénétiques. Sci Geol Mémoire 65. 197 p.Google Scholar
Gauthier-Lafaye, F. Taieb, R. Paquet, H. Chahi, A. Prudencio, I. and Sequeira Braga, M.A., (1993) Composition isotopique de l’oxygène de palygorskites associées à des calcrètes: conditions de formation CR Acad Sci Paris t316 1239–1245.Google Scholar
Hay, R.L. Stoessell, R.K., Singer, A. and Galan, E., (1984) Sepiolite in the Amboseli Basin of Kenya: A new interpretation Palygorskite-sepiolite: Occurrences, genesis and uses. Dev Sedimentol 37 Amsterdam Elsevier 125–136.Google Scholar
Helgeson, H.C. Delany, J.M. Nesbitt, H.W. and Bird, D.K., (1978) Summary and critique of the thermodynamic properties of rock-forming minerals Am J Sci 278 278 229.Google Scholar
Jones, B.F. Galan, E. and Bailey, S.W., (1988) Sepiolite and palygorskite Hydrous phyllosilicates. Rev Mineral 19 Washington, DC Mineral Soc Am. 631–667 10.1515/9781501508998-021.CrossRefGoogle Scholar
Khoury, H.N. Eberl, D.D. and Jones, B.F., (1982) Origin of magnesium clays from the Amargosa Desert, Nevada Clays Clay Miner 30 327–336 10.1346/CCMN.1982.0300502.CrossRefGoogle Scholar
Leguey, S. Pozo, M. and Medina, J.A., (1985) Polygenesis of sepiolite and palygorskite in a fluvio-lacustrine environment in the Neogene Basin of Madrid Miner Petrogr Acta 29 29–301.Google Scholar
Lucas, J. and Prévôt, L., (1976) Etude géologique du gisement du rhassoul de Tamdafelt (Ksabi) Rapport interne de Institut de Géologie, Strasbourg .Google Scholar
McLean, S.A. Allen, B.L. and Craig, J.R., (1972) The occurence of sepiolite and attapulgite on the southern High Plains Clays Clay Miner 20 143–149 10.1346/CCMN.1972.0200305.CrossRefGoogle Scholar
Mifsud, A. Garcia, I. Corma, A., Galan, E. Perez-Rodriguez, J. and Cornejo, J., (1987) Thermal stability and textural properties of exchanged sepiolites Proc 6th Meet Euro Clay Groups 392–394.Google Scholar
Papke, K.G., (1972) A sepiolite-rich playa deposit in southern Nevada Clays Clay Miner 20 20–215 10.1346/CCMN.1972.0200405.CrossRefGoogle Scholar
Parry, W.T. and Reeves, C.C., (1966) Lacustrine glauconitic mica from pluvial Lake Mound, Lynn and Terry Countries, Texas Am Miner 51 229–235.Google Scholar
Peacor, D.R. and Buseck, P.R., (1992) Analytical electron microscopy: X-ray analysis Minerals and reactions at the atomic scale 113–140 10.1515/9781501509735-008.Google Scholar
Post, J.L. Janke, N.C., Singer, A. and Galan, E., (1984) Ballarat sepiolite, Inyo County, California Palygorskite-sepiolite: Occurrences, genesis and uses. Dev Sedimentol 37 Amsterdam Elsevier 159–168.Google Scholar
Raynal, R., (1952) Quelques données nouvelles au sujet de l’Oligo-Miocène du bassin de la Moulouya CRS Soc Geol Fr 6 6–44.Google Scholar
Risacher, F., (1992) Géochimie des bassins à évaporites de l’Altiplano bolivien [these de doctorat] Strasbourg, France Univ Louis Pasteur.Google Scholar
Samuel, J. Rouault, R. and Besnus, Y., (1985) Analyse multiélémentaire standardisée des matériaux géologiques en spectrométrie d’émission par plasma à couplage inductif Analusis 17 17–317.Google Scholar
Stoessell, R.K., (1988) 25°C and 1 atm dissolution experiments of sepiolite and kerolite Geochim Cosmochim Acta 52 52–374 10.1016/0016-7037(88)90092-0.CrossRefGoogle Scholar
Stoessell, R.K. and Hay, R.L., (1978) The geochemical origin of sepiolite and kerolite at Amboseli, Kenya Contrib Mineral Petrol 65 255–267 10.1007/BF00375511.CrossRefGoogle Scholar
Tardy, Y. and Fritz, B., (1981) An ideal solid solution model for calculating solubility of clay minerals Clay Miner 16 16–373 10.1180/claymin.1981.016.4.05.CrossRefGoogle Scholar
Trauth, N. 1977. Argiles evaporitiques dans la sédimentation carbonateé continentale et épicontinentale tertiaire. Bassin de Paris, de Mormoiron et de Salinelles (France) et du Jbel Ghassoul (Maroc). Sci Geol Memoire 49. 195 p.Google Scholar
Wilson, M.J., (1987) A handbook of determinative methods in clay mineralogy Glasgow and London Blackie.Google Scholar