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Particle Morphological Evolution During the Conversion of I/S to Illite in Lower Cretaceous Shales from Sergipe-Alagoas Basin, Brazil

Published online by Cambridge University Press:  28 February 2024

Angélica Varajão
Affiliation:
DEGEO Escola de Minas, UFOP, Campus Morro do Cruzeiro, 35400 Ouro Preto MG, Brazil L.P.A.H, UA 721 C.N.R.S. University of Poitiers, 40 Avenue du Recteur Pineau 86022 POITIERS Cedex, France
Alain Meunier
Affiliation:
L.P.A.H, UA 721 C.N.R.S. University of Poitiers, 40 Avenue du Recteur Pineau 86022 POITIERS Cedex, France
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Abstract

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The illitic end of mixed-layer illite-smectite series (I/S) in shales from Lower Cretaceous Barra de Itiúba Formation, Sergipe-Alagoas basin, was examined with X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). A mathematical decomposition of XRD patterns shows different I/S and illite populations. All the samples contain ordered (R = 1) I/S, poorly crystallized illite (PCI) and well crystallized illite (WCI). A randomly interstratified (R = 0) I/S was also identified in a fractured zone at 1020 m. The percentage of expandable layers in ordered I/S decrease progressively from 20% to 10%. TEM observations show a continuous change in morphology between two basic particle shapes: elongated (lath) and isometric. The size and morphology of particles change with increasing depth. The proportion of laths decreases while isometric particles become predominant. However, both particle types continuously grow and enrich the larger size fraction. The growth process is driven by a mass transfer from the dissolving small particles of predominantly I/S (R = 1) composition to the larger (more illitic) lath and isometric ones. The proportion of lath-shaped particles decreases with depth indicating that the more stable population upon increased burial is the isometric well crystallized illite (WCI) particles. Very large laths are observed in the fault zone where conditions may favor faster growth processes.

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

References

Awwiller, D. N., 1993. Illite/smectite formation and potassium mass transfer during burial diagenesis of mudrocks: A study from the Texas Gulf Coast Paleocen-Eocen. Journal of Sedimentary Petrology 63: 501512.Google Scholar
Baronnet, A., 1982. Ostwald ripening in solution. The case of calcite and mica. Estudios Geologicos 38: 185198.Google Scholar
Boles, J. R., and Franks, S. G. 1979 . Clay diagenesis in Wilcox Sandstone of Southwest Texas: Implications of smectite diagenesis on Sandstone cementation. Journal of Sedimentary Petrology 49: 5570.Google Scholar
Burst, J. F., 1969. Diagenesis of Gulf Coast clayed sediments and its possible relation to petroleum migration. Amer. Assoc. Petrol. Geol. Bull. 53: 7393.Google Scholar
Chai, B. H. T., 1974. Mass transfer of calcite during hydrothermal recrystallization. In Geochemical Transport and Kinetics. Hoffmann, A. W., Giletti, B. J., Yoder, H. S. Jr., and Yund, R. A., eds. 205–218. Carnegie Institute, Washington, D.C.Google Scholar
Champion, D., 1989. Etude des mécanismes de transformation des interstratifiés illite-smectite au cours de la diagenèse: Ph.D. thesis. Université de Paris-Sud, Centre D'Orsay, 204 pp.Google Scholar
Eberl, D. D., and Środoń., J., 1988. Ostwald ripening and interparticle-diffraction effects for illite crystals. Amer. Miner. 73: 13351345.Google Scholar
Eberl, D. D., Środoń, J., Kralik, M., Taylor, B. E., and Peterman, Z. E. 1990 . Ostwald ripening of clays and metamorphic minerals. Science 248: 474477.CrossRefGoogle Scholar
Fernandes, G. J. F., Matos, Z. V., Figueiredo, A. M. F., Fisher, W. L., and Brown, L. F. Jr. 1981 . Basin analysis of the rift phase and oil and gas play analysis, Sergipe-Alagoas Basin, Brasil: PETROBRAS/DEPEX. (internal report).Google Scholar
Freed, R. L., and Peacor, D. R. 1989 . Variability in temperature of the smectite/illite reaction in Gulf Coast sediments. Clay Miner. 1: 171180.CrossRefGoogle Scholar
Glassmann, J. R., Larter, S., Brieds, N., and Lundegard, P. D. 1989 . Shale diagenesis in the Bergen High Area, North Sea. Clays & Clay Miner. 37: 97112.CrossRefGoogle Scholar
Hay, R. L., 1970. Silicate reactions in three lithofacies of a semi-arid basin, Olduvai Gorge, Tanzania. Mineralogical Society of America Special Paper 3, 237255.Google Scholar
Hay, R. L., and Moiola, R. J. 1963 . Authigenic silicate minerals in Searles Lake, California. Sedimentology 2: 312332.CrossRefGoogle Scholar
Hoffman, J., and Hower, J. 1979 . Clay mineral assemblages as low grade metamorphic geothermometers: Application to the thrust faulted disturbed belt of Montana, USA. Soc. Econ. Paleontol. Miner. Spec. Publ. 26: 5579.Google Scholar
Hower, J., Eslinger, E. V., Hower, M. E., and Perry, E. A. Jr. 1976 . Mechanism of burial metamorphism of argilaceous sediments: Mineralogical and chemical evidence. Geol. Soc. Amer. Bull. 87: 725737.2.0.CO;2>CrossRefGoogle Scholar
Inoue, A., 1986. Morphological change in a continuous smectite to illite conversion series by scanning and transmission electron microscopies. Journal of College of Arts and Sciences, Chiba University, B–19, 2333.Google Scholar
Inoue, A., Kohyama, N., Kitagawa, R., and Watanabe, T. 1987 . Chemical and morphological evidence for the conversion of smectite to illite. Clays & Clay Miner. 35: 111120.CrossRefGoogle 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. Miner. 73: 13251334.Google Scholar
Jackson, M. L., 1974. Soil Chemical Analysis—Advanced Course, 2nd ed. Madison, Wisconsin: Published by the author, 895 pp.Google Scholar
Keller, W. D., Reynolds, R. C., and Inoue, A. 1986 . Morphology of clay minerals in the conversion series by scanning electron microscopy. Clays & Clay Miner. 34: 187197.CrossRefGoogle Scholar
Lanson, B., 1990. Mise en évidence des mécanismes de transformation des interstratifiés illite/smectite au cours de la diagenèse: Ph.D. thesis. Université de Paris-Sud, Centre D'Orsay, France, 366 pp.Google Scholar
Lanson, B., and Besson, G. 1992 . Characterization of the end of smectite-to-illite transformation: Decomposition of X-ray patterns. Clays & Clay Miner. 40: 4052.CrossRefGoogle Scholar
Lanson, B., and Champion, D. 1991 . The I/S-to-illite reaction in the late stage diagenesis. Amer. J. of Sci. 291: 473506.CrossRefGoogle Scholar
Lanson, B., and Velde, B. 1992 . Decomposition of X-ray diffraction patterns: A convenient way to describe complex I/S diagenetic evolution. Clays & Clay Miner. 40: 629643.CrossRefGoogle Scholar
Meunier, A., and Velde, B. 1989 . Solid solutions in illite/smectite mixed layer minerals and illite. Amer. Miner. 74: 11061112.Google Scholar
Nadeau, P. H., 1985. The physical dimension of fundamental clay particles. Clays & Clay Miner. 20: 499514.CrossRefGoogle Scholar
Nadeau, P. H., and Reynolds, R. C. 1981 . Burial contact metamorphism in the Mancos Shale. Clays & Clay Miner. 29: 249259.CrossRefGoogle Scholar
Perry, E., and Hower, J. 1970 . Burial diagenesis in Gulf Coast pelitic sediments. Clays & Clay Miner. 18: 165177.CrossRefGoogle 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.CrossRefGoogle Scholar
Ponte, F. C., and Asmus, H. E. 1976 . The Brazilian marginal basins: Current state of knowledge. Acad. Bras. Cienc., São Paulo, Brasil, 48: 215240.Google Scholar
Remy, R. R., and Ferrell, R. 1989 . Distribution and origin of analcime in marginal lacustrine mudstone of the Green River Formation, South-Central Uinta Basin, Utah. Clays & Clay Miner. 37: 419432.CrossRefGoogle Scholar
Reynolds, R. C., 1985. NEWMOD: A computer program for the calculation of one-dimensional patterns of mixed-layered clays. R. C. Reynolds, 8 Brook Rd., Hanover, New Hampshire 03755.Google Scholar
Sato, T., Watanabe, T., and Otsuka, R. 1992 . Effects of layer charge, charge location, and energy change on expansion properties of dioctahedral smectites. Clays & Clay Miner. 40: 103113.CrossRefGoogle Scholar
Środoń, J., Elsass, F., McHardy, W. J., and Morgan, D. J. 1992 . Chemistry of illite-smectite inferred from TEM measurements of fundamental particles. Clay Miner. 27: 137158.CrossRefGoogle Scholar
Touchard, G., Velde, B., Cailleu, L., Badri, H., and Borzeix, J. 1993 . Form analysis software by image processing. Applications to clay particles and soil structure. Proceedings of 6ECS, Prague, 12: 263268.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.CrossRefGoogle Scholar
Velde, B., and Vasseur, G. 1992 . Estimation of the diagenetic smectite to illite transformation in time-temperature space. Amer. Miner. 77: 967976.Google Scholar
Whitney, G., and Velde, B. 1993 . Changes in particle morphology during illitization: An experimental study. Clays & Clay Miner. 41: 209218.CrossRefGoogle Scholar