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Mineral phases and processes within green peloids from two Recent deposits near the Congo River Mouth

Published online by Cambridge University Press:  09 July 2018

P. Giresse ,
A. Wiewiora  and
B. Lacka
P. Giresse
Affiliation:
Laboratoire de Recherches de Sédimentologie Marine, Université de Perpignan — Avenue de Villeneuve, 66025 Perpignan, France
A. Wiewiora
Affiliation:
Institute of Geological Sciences, Polish Academy of Sciences, al. Zwirki i Wigury 93, 02-089 Warsaw, Poland
B. Lacka
Affiliation:
Institute of Geological Sciences, Polish Academy of Sciences, al. Zwirki i Wigury 93, 02-089 Warsaw, Poland
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Abstract

In the Recent sediments of the Congo River estuary, the green Fe-bearing peloids containing 7 Å phases are nearer to the river mouth than the 10 Å phyllosilicates. Measurements of d060 for 7 Å minerals in various density fractions indicated a progressive transformation of kaolinite into trioctahedral 1:1 phyllosilicates in the zone with a high sedimentation rate. Projection of the chemical composition from the approximate crystallochemical formula on to a classification field confirmed the transformation of kaolinite into a 7 Å Fe-rich phase via substitution of Fe2+ and Mg for Al in the octahedral sheet, with insignificant changes in the tetrahedral sheet. The resultant transition phase has a composition closer to greenalite than berthierine. The possible advancement of the evolution process was stopped by massive formation of goethite. The 10 Å minerals formed in the grains deposited in the off-shore sediments have a homogenous composition and occur in association with goethite and quartz. These peloids show an enrichment in Al although no kaolinite is present.

Type
Research Article
Information
Clay Minerals , Volume 23 , Issue 4 , December 1988 , pp. 447 - 458
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1988

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References

Bailey, S.W. (1980) Structures of layer silicates. Pp. 1–124 in: Crystal Structures of Clay Minerals and their X- ray Identification. (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Bhattacharyya, D.P. (1983) Origin of berthierine in ironstone. Clays Clay Miner. 31, 173–182.Google Scholar
Boyer, P.S., Guines, E.A., Lynch-Bloose, M.A. & Stotzman, R.A. (1977) Greensand fecal pellets from New Jersey. J. Sed. Pet. 47, 267–280.Google Scholar
Brindley, G.W. (1982) Chemical composition of berthierines-a review. Clays Clay Miner. 30, 153–155.Google Scholar
Brown, G. (1980) Associated minerals. Pp. 361–410 in: Crystal Structures of Clay Minerals and their X-ray Identification. (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Figueres, G., Martin, J.M. & Meybeck, M. (1978) Iron behaviour in the Zaire estuary. Neth. J. Sea Res. 12, 329–337.Google Scholar
Giresse, P. (1985) Le fer et les glauconies au large du fleuve Congo. Sci. Geol. Strasbourg 38, 293–322.Google Scholar
Giresse, P. & Odin, G. (1973). Nature mineralogique et origine des glauconies du plateau continental du Gabon et du Congo. Sedimentology 20, 457–488.CrossRefGoogle Scholar
Giresse, P., Wiewiora, A. & Lacka, B. (1987) Migration des elements et mineralogenese dans les grains verts recents au large de Tembouchure du Congo. Archiwum Mineral. 42, 5–30.Google Scholar
Hein, J.R., Allward, A.O. & Griggs, C.G. (1974) The occurrence of glauconite in Monterey bay, California. Diversity, origins and sedimentary environmental significance. J. Sed. Pet. 44, 562–571.Google Scholar
Norrish, K. & Taylor, R.M. (1961) The isomorphous replacement of iron by aluminium in soil goethites. J. Soil Sci. 12, 294–306.Google Scholar
Odin, G.S. & Matter A. (1981) De glauconiarum origine. Sedimentology 28, 611–641.Google Scholar
Porrenga, D.H. (1967) Glauconite and chamosite as depth indicators in the marine environment. Mar. Geol. 5, 485–501.Google Scholar
Reynolds, R.C. (1980) Interstratified clay minerals. Pp. 249–303 in: Crystal Structures of Clay Minerals and their X-ray Identification. (Brindley, G.W. & Brown, G., editors). Mineralogical Society, London.Google Scholar
Ross, M. (1968) X-ray diffraction effects by non-ideal crystals of biotite, muscovite, montmorillonite, mixedlayered clays, graphite and periclase. Zeitsh.Jur Kristal. 126.Google Scholar
Tardy, Y. & Gac, J.Y. (1979) Controle de la composition chimique des solutions par la precipitation des mineraux dans les sols. Ebauche d'un modele thermodynamique pour la formation des argiles. Bull. AFES 2, 107–123.Google Scholar
Van Houten, F.B. & Purucker, M.E. (1984) Glauconite peloids and chamositic ooids–favorable factors, constraints and problems. Earth-Sci. Rev. 20, 211–243.Google Scholar
Velde, B. & Odin, G.S. (1975) Further information related to the origin of glauconite. Clays Clay Miner. 23, 376–381.Google Scholar
Weiss, Z., Durovic, S., Wiewiora, A. & Rieder, M. (1989) Polytypes of Phyllosilicates and their X-ray Identification. PWN-Elsevier (Submitted).Google Scholar
Wiewiora, A. (1987) Polytypes of phyllosilicates: typomorphic importance, crystal chemistry and X-ray identification. Summaries-Proc. 6th Meet. European Clay Groups, 52–54. Google Scholar