Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-23T01:17:03.508Z Has data issue: false hasContentIssue false

Formation of Authigenic Illite in Palaeocene Mudrocks from the Central North Sea: a Study by High Resolution Electron Microscopy

Published online by Cambridge University Press:  28 February 2024

Jennifer M. Huggett*
Affiliation:
Department of Geology, Imperial College, London, SW7 2BP, U.K.
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.

The mode of growth of authigenic, lath-shaped illitic particles has been investigated using field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). Two types of clay lath have been identified: overgrowths on platelets of illite or illite-smectite and discrete particles. Both are neoformed and show a slight increase in abundance with depth over the 70 m depth interval sampled. Interpretation of lattice fringe data is not unambiguous but indicates that the clay is either illite or illite-smectite with R1 structure. The formation of discrete particles of authigenic illite, or even R1 illite-smectite, is compatible with present burial depths and a regional geothermal gradient of approximately 40°C/km. This illite also differs from many previous reported occurrences of authigenic illite in mudrocks in that it appears to have formed, without being preceded by progressive illitization of illite-smectite.

Type
Research Article
Copyright
Copyright © 1995, The Clay Minerals Society

References

Ahn, J. H., and Peacor, D. R. 1986. Transmission and analytical electron microscopy of the smectite-to-illite transition. Clays & Clay Miner. 34: 165179.Google Scholar
Amouric, M., and Olives, J. 1991. Illitization of smectite as seen by high-resolution electron microscopy. Eur. J. Mineral. 3: 831835.Google Scholar
Baños, J. O., Amouric, M., Fouquet, C. De, and Baronnet, A. 1983. Interlayering and interlayer slip in biotite as seen by HRTEM. Amer. Mineral. 68: 754758.Google Scholar
Bautier, M. D., Peacor, D. R., and O'Niel, J. R. 1992. Smectite-illite transition in Barbados accretionary wedge sediments: TEM and AEM evidence for dissolution/crystallisation at low temperature. Clays & Clay Miner. 38: 3346.Google Scholar
Boles, J. R., and Franks, S. G. 1979. Clay diagenesis in Wilcox sandstones of southwest Texas. J. Sed. Petrol. 49: 5570.Google Scholar
Bruce, C. H., 1984. Smectite dehydration—Its relation to structural development and hydrocarbon accumulation in the Northern Gulf of Mexico basin. Amer. Assoc. Petrol. Geol. Bull. 68: 673683.Google Scholar
Burton, W. K., Cabrera, N., and Frank, F. C. 1951. The growth of crystals and the equilibrium structure of their faces. Phil. Trans. Royal Soc. 243: 299358.Google Scholar
Buseck, P. R., and Ijima, S. 1974. High resolution electron microscopy of silicates. Amer. Mineral. 59: 121.Google Scholar
Eberl, D. D., and Sródon, J. 1988. Ostwald ripening and interparticle diffraction effects for illite crystals. A mer. Mineral. 73: 13351345.Google Scholar
Ehrenberg, S. N., and Nadeau, P. H. 1989. Formation of diagenetic illite in sandstones of the Garn Formation, Haltenbanken area, mid-Norwegian continental shelf. Clay Miner. 24: 233253.Google Scholar
Freed, R. L., 1981. Shale mineralogy and burial diagenesis of the Frio and Vicksburg Formations in two geopressured wells, McAllen Ranch area, Hidalgo County, Texas. Trans. Gulf Coast Assoc. Geol. Soc. 31: 189293.Google Scholar
Glassman, J. R., 1992. The fate of feldspars in the Brent Group reservoirs, North Sea: a regional synthesis of diagenesis in shallow, intermediate and deep burial environments. In Geology of the Brent Group. Morton, A. C., Haszeldine, R. S., Giles, M. R., and Brown, S., eds. London: The Geological Society, 329350.Google Scholar
Guthrie, G. D. Jr., and Veblen, D. R. 1989. High resolution transmission electron microscopy of mixed layer illite/smectite: Computer simulations. Clays & Clay Miner. 37: 111.Google Scholar
Guthrie, G. D. Jr., and Veblen, D. R. 1990. Interpreting one-dimensional, high-resolution transmission electron micrographs of sheet silicates by computer simulation. Amer. Mineral. 75: 276288.Google Scholar
Hoffman, J., and Hower, J. 1979. Clay mineral assemblages as low grade metamorphic geothermometers: Application to the thrust faulted disturbed belts of Montana. U.S.A. SEPM Special Publication. 26: 5579.Google Scholar
Hower, J., Eslinger, E. V., Hower, M. E., and Perry, E. A. 1976. Mechanisms of burial metamorphism of argillaceous sediments: 1 Mineralogical and chemical evidence. Geol. Soc. Amer. Bull. 897: 725737.Google Scholar
Huang, W. L., 1990. Experimental illitization of illite and recrystallization of illite. In Programme and Abstracts, Research Conference on Phyllosilicates as Indicators of Very Low Grade Metamorphism and Diagenesis. Manchester: IGCP, 10.Google Scholar
Huggett, J. M., 1989. Scanning electron microscope and X-ray diffraction investigations of mudrock fabrics, textures and mineralogy. Scanning Microscopy 3: 99109.Google Scholar
Huggett, J. M., 1992. Petrography, mineralogy and diagenesis of overpressured Tertiary and Late Cretaceous mudrocks from the East Shetland Basin. Clay Miner. 27: 487506.Google Scholar
Huggett, J. M., Diagenesis in a Tertiary sandstone-mudrock sequence from the Central North Sea, U.K. (in press).Google Scholar
Inoue, A., Kohyama, H., Kitagawa, R., and Watanabe, T. 1987. Chemical and morphological evidence for the conversion of smectite to illite. Clays & Clay Miner. 35: 111120.Google Scholar
Inoue, A., Velde, B., Meunier, A., and Touchard, G. 1988. Mechanism of illite formation during smectite-to-illite conversion in a hydrothermal system. Amer. Mineral. 73: 13251334.Google Scholar
Jennings, S., and Thompson, G.R. 1986. Diagenesis in Plio-Pleistecene sediments in the Colorado River delta, southern California. J. Sed. Petrol. 56: 8998.Google Scholar
Keller, W. D., Reynolds, R. C., and Inoue, A. 1986. Morphology of clay minerals in the smectite-to-illite conversion series by scanning electron microscopy. Clays & Clay Miner. 34: 187197.Google Scholar
Lee, J. H., Ahn, J. H., and Peacor, D. R. 1985. Textures in layered silicates: Progressive changes through diagenesis and low-temperature metamorphism. J. Sed. Petrol. 55: 532540.Google Scholar
Murakami, T., Sato, T., and Watanabe, T. 1993. Micro-structure of interstratified illite/smectite at 123 K: a new method for HRTEM examination. Amer. Mineral. 78: 465468.Google Scholar
Nadeau, P. H., Tait, J. M., McHardy, W. J., and Wilson, M. J. 1984. Interstratified XRD characteristics of physical mixtures of elementary clay particles. Clay Miner. 19: 6776.Google Scholar
O'Brien, N. E., and Slatt, R. M. 1990. Argillaceous Rock Atlas. New York: Springer Verlag, 141 pp.Google Scholar
Peacor, D. R., 1992. Diagenesis and low-grade metamorphism of shales and slates. In Reviews in Mineralogy 27 Mineral Reactions at the Atomic Scale: Transmission Electron Microscopy. Buseck, P. R., ed. Washington: Miner. Soc. Amer., 335379.Google Scholar
Pearson, M., and Small, J. S. 1988. Illite-smectite diagenesis and palaeotemperatures in Northern North Sea Quaternary to Mesozoic shale sequences. Clay Miner. 23: 109132.Google Scholar
Pollastro, R. M., 1985. Mineralogical and morphological evidence for the formation of illite at the expense of illite/smectite. Clays & Clay Miner. 33: 265274.Google Scholar
Pollastro, R. M., 1990. The illite/smectite geothermometer—Concepts, methodology and application to basin history and hydrocarbon generation. In Applications of Thermal Maturity Studies to Energy Exploration. Nuccio, V. F., and Barker, C. E., eds. Denver: Rocky Mountain Section, SEPM, 118.Google Scholar
Reynolds, R. C. Jr., and Hower, J. 1970. The nature of interlayering in mixed layer illite-montmorillonites. Clays & Clay Miner. 18: 165177.Google Scholar
Reynolds, R. C. Jr. 1985. NEWMOD© A Computer Program for the Calculation of One-Dimensional Diffraction Patterns of Mixed-Layer Clays. R. C. Reynolds Jr. 8 Brook Drive, Hanover, New Hampshire.Google Scholar
Roberson, H. E., and Lahann, R. W. 1981. Smectite to illite conversion states: Effects of solution chemistry. Clays & Clay Miner. 29: 129135.Google Scholar
Rosenberg, P. E., Kittrick, J. A., and Aja, S. U. 1990. Mixed-layer illite/smectite: A multiphase model. Amer. Mineral. 75: 11821185.Google Scholar
Small, J. S., 1993. Experimental determination of the rates of precipitation of authigenic illite and kaolinite in the presence of aqueous oxalate and comparison to the K/Ar ages of authigenic illite in reservoir sandstone. Clays & Clay Miner. 41: 191208.Google Scholar
Środón, J., 1980. Precise identification of illite/smectite interstratifications by X-ray powder diffraction. Clays & Clay Miner. 28: 401411.Google Scholar
Sródon, J., Andreoli, C., Elsass, F., and Robert, M. 1990. Direct high resolution electron microscopic measurement of expandability of mixed layer illite/smectite in bentonite rock. Clays & Clay Miner. 38: 373379.Google Scholar
Vali, H., and Köster, H. M. 1986. Expanding behaviour, structural disorder, regular and random irregular interstratification of 2: 1 layer-silicates studied by high resolution images of transmission electron microscopy. Clay Miner. 21: 827859.Google Scholar
Veblen, D. R., Guthrie, G. D., Livi, K. J. T., and Reynolds, R. C. Jr. 1990. High resolution transmission electron microscopy and electron diffraction of mixed layer illite/smectite: Experimental results. Clays & Clay Miner. 38: 113.Google Scholar
Velde, B., Suzuki, T., and Nicot, E. 1986. Pressure-temperature-composition of illite/smectite mixed-layer minerals: Niger Delta mudstones and other examples. Clays & Clay Miner. 34: 435441.Google Scholar
Yau, Y.-C., Lee, J. H., Peacor, D. R., and McDowell, S. D. 1983. TEM study of illite diagenesis in shale of Salton Sea geothermal field, California. In Program and Abstracts, 20th Annual Meeting Clay Minerals Society, 42.Google Scholar
Yau, Y-C., Peacor, D. R., and McDowell, S. D. 1987. Smectite-to-illite reactions in Salton Sea shales: A transmission and analytical electron microscopy study. J. Sed Petrol. 57: 335342.Google Scholar