Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-03T20:41:26.910Z Has data issue: false hasContentIssue false

Ordered illite-smectite and kaolinite-smectite: pedogenic minerals in a Lower Carboniferous paleosol sequence, South Wales?

Published online by Cambridge University Press:  09 July 2018

D. Robinson
Affiliation:
Department of Geology, Wills Memorial Building, University of Bristol, Queen's Road, Bristol BS8 1RJ
V. P. Wright
Affiliation:
Department of Geology, Wills Memorial Building, University of Bristol, Queen's Road, Bristol BS8 1RJ

Abstract

Mixed-layer clay minerals of illite-smectite, having smectite contents ∼25% and IS ordering, kaolinite-smectite, and a three-component variety with kaolinite-smectite-chlorite-like material are described from a Carboniferous paleosol in South Wales. The clays, which are restricted to particular horizons, are unusual occurrences in a pedogenic sediment and pose particular problems as to their genesis. Positive geological evidence, principally in the form of mineralogical and organic thermal maturation data, demonstrates that the rocks of the region cannot have reached diagenetic temperatures > 100°C. This would appear to suggest a pedogenic rather than a diagenetic origin for these clays. In these sediments the only plausible mechanism of illitization to produce the illite-smectite would be by repeated wetting and drying cycles causing irreversible K fixation. Such cycles would be entirely realistic for a vertisol-like paleosol formed on overbank deposits in a floodplain environment subject to strong seasonal moisture contrasts. If this interpretation is correct, this illite-smectite represents the most illitic yet recorded from a non-burial or non-hydrothermal environment.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1987

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

April, R.H. (1980) Regularly interstratified chlorite vermiculite in contact metamorphosed red beds. Newark Group, Connecticut Valley. Clays Clay Miner. 28, 111.CrossRefGoogle Scholar
Brown, G. & Brindley, G. W. (1980) X-ray diffraction procedures for clay mineral identification. Pp. 305359 in: Crystal Structures of Clay Minerals and their X-ray Identification (Brindley, G. W. & Brown, G., editors). Mineralogical Society, London.CrossRefGoogle Scholar
Buol, S.W., Hole, F.D. & McCraken, R.J. (1980) Soil Genesis and Classification. Iowa State Univ. Press, Ames, Iowa. 404 pp.Google Scholar
Burst, J.F. (1959) Post diagenetic clay mineral environmental relationships in the Gulf Coast Eocene. Clays Clay Miner. 6, 327341.CrossRefGoogle Scholar
Cradwick, P.D. & Wilson, M.J. (1972) Calculated X-ray diffraction profiles for interstratified kaolinite-montmorillonite. Clay Miner. 9, 395405.CrossRefGoogle Scholar
Fitzpatrick, E.A. (1983) Soils: their Formation, Classification and Distribution. Longman, London. 353 pp.Google Scholar
Gill, W.D., Khalaf, F.I. & Massoud, M.S. (1977) Clay minerals as an index of the degree of metamorphism of the carbonate and terrigeneous rocks in the South Wales coalfield. Sedimentology 24, 675691.CrossRefGoogle Scholar
Gill, W.D., Khalaf, F.I. & Massoud, M.S. (1979) Organic matter as indicator of the degree of metamorphism of the Carboniferous rocks in the South Wales Coalfield. J. Petrol. Geol. 1, 3662.CrossRefGoogle Scholar
Herbillon, A.J., Frankart, R. & Vielvoye, L. (1981) An occurrence of interstratified kaolinite-smectite minerals in a red-black soil toposequence. Clay Miner. 16, 195201.CrossRefGoogle Scholar
Hoffman, J. & Hower, J. (1979) Clay mineral assemblages as low grade metamorphic geothermometers: Application to the thrust faulted Disturbed Belt of Montana U.S.A. Pp. 5579 in: SEPM Spec. Publ. 26 (Scholle, P. A. & Schluger, P. R., editors).CrossRefGoogle Scholar
Hower, J. (1981) X-ray identification of mixed-layer clay minerals. Pp. 3959 in: Clays and the Resource Geologist (Longstaffe, F. J., editor). Mineral. Assoc. Canada, Short Course Handbook 7.Google Scholar
Hower, J., Eslinger, E.V., Hower, M.E. & Perry, E.A. (1976) Mechanisms of burial metamorphism of argillaceous sediment. 1, mineralogical and chemical evidence. Bull. geol. Soc. Am. 87, 725737.2.0.CO;2>CrossRefGoogle Scholar
Leeder, M.R. (1975) Pedogenic carbonates and flood plain sediment accretion rates: a quantitative model for alluvial arid-zone lithofacies. Geol. Mag. 112, 257270.CrossRefGoogle Scholar
MacEwan, D.M.C. (1950) Some notes on the recording and interpretation of X-ray diagrams of soil clays. J. Soil Sci. 1, 90103.CrossRefGoogle Scholar
Mamy, J. & Gaultier, J.P. (1975) Etude de l'evolution de l'orde cristallin dans la montmorillonite en relation avec la diminution d'echangeabilite du potassium. Proc. Int. Clay Conf. Mexico City, 149155.Google Scholar
McDowell, S.D. & Elders, W.A. (1980) Authigenic layer silicate minerals in borehole Elmore 1, Salton Sea Geothermal Field, California U.S.A. Contr. Miner. Petr. 74, 293310.CrossRefGoogle Scholar
Nadeau, P.H., Wilson, M.J., McHardy, W.J. & Tait, J.M. (1984) Interparticle diffraction: a new concept for interstratified clays. Clay Miner. 19, 757769.CrossRefGoogle Scholar
Nadeau, P.H., Wilson, M.J., McHardy, W.J. & Tait, J.M. (1985) The conversion of smectite to illite during diagenesis: evidence from some illitic clays from bentonites and sandstones. Mineral. Mag. 49, 393400.CrossRefGoogle Scholar
Norrish, K. & Pickering, J.G. (1983) Clay minerals. Pp. 281308 in: Soils: an Australian Viewpoint. CSIRO Melbourne/Academic Press, London.Google Scholar
Pawluk, S. (1963) Characteristics of 14 A clay minerals in the B horizons of podzolised soils of Alberta. Clays Clay Miner. 11, 7482.CrossRefGoogle Scholar
Perry, E.A. & Hower, J. (1970) Burial diagenesis in Gulf Coast pelitic sediments. Clays Clay Miner. 18, 165177.CrossRefGoogle Scholar
Peterson, M.N.A. (1961) Expandable chloritic clay minerals from Upper Mississippian carbonate rocks of the Cumberland Plateau in Tennessee. Am. Miner. 46, 12451269.Google Scholar
Poncelet, G.M. & Brindley, G.W. (1967) Experimental formation of kaolinite from montmorillonite at low temperatures. Am. Miner. 52, 11611173.Google Scholar
Reynolds, R.C. (1980) Interstratified clay minerals. Pp. 249303 in: Crystal Structures of Clay Minerals and their X-ray Identification (Brindley, G. W. & Brown, G., editors). Mineralogical Society, London.CrossRefGoogle Scholar
Rich, C.I. (1968) Hydroxy interlayers in expansible layer silicates. Clays Clay Miner. 16, 1530.CrossRefGoogle Scholar
Rimmer, S.M. Eberl, D.D. (1982) Origin of an underclay as revealed by vertical variations in mineralogy and chemistry. Clays Clay Miner. 30, 422430.CrossRefGoogle Scholar
Schultz, L.G. (1978) Mixed-layer clay in the Pierre Shale and equivalent rocks, Northern Plains Regions. U.S.G.S. Prof. Paper 1064-A.CrossRefGoogle Scholar
Schultz, L.G., Shepard, A.O., Blackmon, P.D. & Starkey, H.C. (1971) Mixed-layer kaolinite-montmorillonite from the Yucatan Peninsula. Mexico. Clays Clay Miner. 19, 137150.CrossRefGoogle Scholar
Środoń, J. (1980) Precise identification of illite smectite interstratifications by X-ray powder diffraction. Clays Clay Miner. 28, 401411.CrossRefGoogle Scholar
Środoń, J. (1984a) Illite/smectite in low-temperature diagenesis: data from the Miocene of the Carpathian Foredeep. Clay Miner. 19, 205215.CrossRefGoogle Scholar
Środoń, J. (1984b) X-ray identification of illitic materials. Clays Clay Miner. 32, 337349.CrossRefGoogle Scholar
Środoń, J. & Eberl, D.D. (1984) Illite. Pp. 495544: Reviews in Mineralogy, 13 Micas (Bailey, S. W., editor). Mineralogical Society of America, Washington.Google Scholar
Straub, J.R. & Cohen, A.D. (1978) Kaolinite-enrichment beneath coals; a modern analog, Snuggedy Swamp, South Carolina. J. Sedim. Petrol. 48, 203210.Google Scholar
Suchecki, R.K., Perry, E.A. & Hubert, J.F. (1977) Clay petrology of Cambro-Ordovician continental margin, Cow Head Klippe, Western Newfoundland. Clays Clay Miner. 25, 163170.CrossRefGoogle Scholar
Watts, N.L. (1980) Quaternary pedogenic calcretes from the Khalahari (southern Africa): mineralogy, genesis and diagenesis. Sedimentology 27, 661686.CrossRefGoogle Scholar
Wieder, M. & Yaalon, D.H. (1974) Effect of matrix composition on carbonate nodule crystallization. Geoderma 11, 95121.CrossRefGoogle Scholar
Wilson, M.J. (1986) Soil smectites and associated interstratified minerals: Recent developments. Proc. Int. Clay Conf. Denver (in press).Google Scholar
Wilson, M.J. & Cradwick, P.D. (1972) Occurrence of interstratified kaolinite-montmorillonite in some Scottish soils. Clay Miner. 9, 435437.CrossRefGoogle Scholar
Wilson, M.J. & Nadeau, P.H. (1985) Interstratified clay minerals and weathering processes. Pp. 71118 in: The Chemistry of Weathering (Drever, J. I., editor). D. Reidel, Dordrecht. Holland.Google Scholar
Wright, V.P. (1980) Climatic fluctuations in the Lower Carboniferous. Naturwissensehaften 67, 252253.CrossRefGoogle Scholar
Wright, V.P. (1982) Calcrete palaeosols from the Lower Carboniferous Llanelly Formation, South Wales. Sedim. Geology 33, 133.CrossRefGoogle Scholar
Yerima, B.P.K., Calhoun, F.G., Senkaji, A.L. & Dixon, J.B. (1985) Occurrence of interstratified kaolinitesmectite in E1 Salvador Vertisols. Soil Sci. Soc. Am. J., 49, 462466.CrossRefGoogle Scholar