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Diagenetic chlorite formation in some Mesozoic shales from the Sleipner area of the North Sea

Published online by Cambridge University Press:  09 July 2018

A. Hurst*
Affiliation:
Statoil, Forus, Postboks 300, N-4001 Stavanger, Norway

Abstract

Diagenetic chlorite is forming as a result of temperature-controlled burial diagenesis in shales from the Sleipner area of the North Sea. Accompanying chlorite diagenesis, kaolinite and illite-smectite decrease in abundance, and illite increases in abundance. These clay mineral transformations occur between 122–126°C at temperatures higher than normally expected for chlorite diagenesis. Kaolinite and ordered illite-smectite are largely unaffected by diagenesis below 100°C. It is proposed that chlorite diagenesis is thus delayed due to the absence of a source of ions resulting from smectite decomposition. Clay mineralogy is of no lithostratigraphic use in the Jurassic sediments of the Sleipner area. However, the zone of chlorite diagenesis is a reliable indicator of maximum burial temperature.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1985

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References

April, R.H. (1981) Clay petrology of the Upper Triassic/Lower Jurassic terrestrial strata of the Newark Supergroup, Connecticut Valley U.S.A. Sed. Geol. 29, 283307.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
Caballero, M.A. & Martin-Vivaldi, J.L. (1972) Distribution of clay minerals in the Spanish Triassic sedimentary basins. Proc. Int. Clay Conf. Madrid, 259268.Google Scholar
Cooper, B.S., Coleman, S.H., Barnard, P.C. & Butterworth, J.S. (1975) Palaeotemperatures in the Northern North Sea Basin, 59-62 °N. Pp. 487492 in: Petroleum Geology of the Continental Shelf of North-WestEurope (Woodland, A.W., editor). Applied Science Publishers, Barking, Essex.Google Scholar
Dypvik, H. (1983) Clay mineral transformation in Tertiary and Mesozoic sediments from North Sea. Am. Assoc. Petrol. Geol. Bull. 67, 160165.Google Scholar
Eberl, D. & Hower, J. (1976) Kinetics of illite formation. Geol. Soc. Amer. Bull. 87, 13261330.2.0.CO;2>CrossRefGoogle Scholar
Frey, M. (1978) Progressive low-grade metamorphism of a black shale formation, Central Swiss Alps, with special references to pyrophyllite and margafite hearing assemblages. J. Petrol. 19, 93135.Google Scholar
Gretner, P.E. (1981) Geothermics: Using Temperature in Hydrocarbon Exploration. AAPG Education Short Course Note Series 17, 170 pp.Google Scholar
Hallam, A. (1981) Facies Interpretation and the Stratigraphic Record. W. H. Freeman, Oxford & San Francisco.Google 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. 5580 in: Aspects of Diagenesis (Scholle, P. A. & Schluger, P. R., editors). SEPM Spec. PubL 26.Google Scholar
Hower, J., Eslinger, E.V., Hower, M.E. & Perry, E.A. (1976) Mechanism of burial metamorphism of argillaceous sediments: I. Mineralogical and chemical evidence. Geol. Soc. Amer. Bull. 87, 725737.Google Scholar
Hurst, A. (1982) The clay mineralogy of Jurassic shales from Brora, NE Scotland. Proc. Int. Clay Conf. Bologna & Pavia, 677684.Google Scholar
Karlsson, W., Vollset, J., Bjørlykke, K. & Jørgensen, P. (1979) Changes in mineralogy composition of Tertiary sediments from North Sea wells. Proc. Int. Clay Conf. Oxford, 281289.Google Scholar
Larsen, R.M. & Jaarvlk, L.J. (1981) The geology of the Sleipner field complex. Norwegian Syrup. Explor. Norsk Petroleumsforening. Paper 15, 31 pp.Google Scholar
Pearson, M.J., Watkins, D. & Small, J.S. (1982) Clay diagenesis and maturation in Northern Sea sediments. Proc. Int. Clay Conf. Bologna & Pavia, 665675.Google Scholar
Pearson, M.J., Watkins, D., Pittion, J.-L., Caston, D. & Small, J.S. (1983) Aspects of burial diagenesis, organic maturation and palaeothermal history of an area in the South Viking Graben, North Sea. pp. 161173 in: Petroleum Geochemistry and Exploration of Europe (Brooks, J., editor). Geological Society Special Publication 12, Blackwell, Oxford.Google Scholar
Perry, E. & Hower, J. (1970) Burial diagenesis in Gulf coast pelitic sediments. Clays Clay Miner. 18, 165177.CrossRefGoogle Scholar
Velde, B. (1977) Clays and Clay Minerals in Natural and Synthetic Systems. Elsevier, Amsterdam.Google Scholar
Weir, A.H., Ormerod, E.C. & El-Mansey, I.M.I. (1975) Clay mineralogy of sediments of the Western Nile Delta. Clay Miner. 10, 369386.CrossRefGoogle Scholar