Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-29T12:32:10.676Z Has data issue: false hasContentIssue false
  • English
  • Français

Significance of K-Ar ages of authigenic illitic clay minerals in sandstones and shales from the North Sea

Published online by Cambridge University Press:  09 July 2018

J. C. Matthews ,
B. Velde  and
H. Johansen
J. C. Matthews
Affiliation:
Laboratorie de Géologie, Ur 1316 CNRS, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
B. Velde
Affiliation:
Laboratorie de Géologie, Ur 1316 CNRS, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
H. Johansen
Affiliation:
Laboratorie de Géologie, Ur 1316 CNRS, Ecole Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France Institutt for Energiteknikk, Instituttveien 18, Postboks 40, N-2007 Kjeller, Norway
Get access Rights & Permissions [Opens in a new window]

Abstract

Petrographic, X-ray diffraction, and microprobe analyses have been used to assess the significance of illite K-Ar ages from sandstones of two North Sea wells. Three closely spaced samples in one well from the upper Statfjord Formation yield similar ages (69-79 Ma) although the illites formed from different precursor minerals. Pore-filling illite in the upper Brent and the Upper Skagerrak Formations from a second well formed by replacing groundmass clays and other detrital minerals. The average layer charge and K+ content increase slightly with depth (0.69-0.80 K+) due to minor reaction and crystal growth during burial diagenesis. These K-Ar ages increase from 15 to 33 Ma within a 500 m depth interval. The K-Ar age vs. depth relationship for these samples corresponds to the burial rate during the middle Tertiary. In examples of extensive illitization of pore-filling clays in sandstones with little subsequent evolution of the clay minerals, the K-Ar ages indicate the age of diagenetic events.

In contrast, illitic minerals in shales from the Skagerrak Formation in the second well yield an age (108 Ma) that is much older than the clays in the sandstones, but is still younger than stratigraphic age. The K-Ar ages from illitic clay in shales reported in the literature can get younger, older, or remain essentially unchanged with increasing depth. These age vs. depth trends reflect the complex interplay of crystal growth and dissolution during diagenesis, as well as probable contamination by non-recrystallized detrital illites. The K-Ar ages of illitic clays, therefore, evolve in a different manner in shales than in sandstones.

Type
Research Article
Information
Clay Minerals , Volume 29 , Issue 3 , September 1994 , pp. 379 - 390
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1994

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

Aronson, J.L. & Hower, J. (1976) Mechanism of burial metamorphism of argillaceous sediment: 2. Radiogenic argon evidence. Geol. Soc. Am. Bull. 87, 738–74.2.0.CO;2>CrossRefGoogle Scholar
Bjørlykke, K., Aagaard, P., Dypvik, H., Hastings, D.S. & Harper, A.S. (1986) Diagenesis and reservoir properties of Jurassic sandstones from the Haltenbanken area, offshore mid-Norway. Pp. 275–386 in: Habitat of Hydrocarbons on the Norwegian Continental Shelf (Spencer, A.M., editor). Norwegian Petroleum Society, London.Google Scholar
Bjørlykke, K. & Aagaaard, P. (1992) Clay Minerals in North Sea Sandstones. Pp. 65-80 in: Origin, Diagenesis, and Petrophysics of Clay Minerals in Sandstones. SEPM Special Publication No. 47.CrossRefGoogle Scholar
Burley, S.D. & Flisch, M. (1989) K-Ar geochronology and the timing of detrital I/S clay illitization and authigenic illite precipitation in the Piper and Tartan Fields, Outer Moray Firth, UK North Sea. Clay Miner. 24, 285–315.CrossRefGoogle Scholar
Ehrenberg, S.N. & Nadeau, P.H. (1989) Formation of diagenetic illite in sandstones of the Garn Formation, Haltenbanken area, Mid-Norwegian continental shelf. Clay Miner. 24, 233–253.CrossRefGoogle Scholar
Ehrenberg, S.N., Aagaaro, P., Wilson, M.J., Fraser, A.R. & Duthie, D.M.L. (1993) Depth-dependent transformation of kaolinite to dickite in sandstones of the Norwegian continental shelf. Clay Miner. 28, 325–352.CrossRefGoogle Scholar
Glasmann, J.R., Lundegard, P.D., Clark, R.A., Penny, B.K. & Collins, I.D. (1989a) Geochemical evidence for the history of diagenesis and fluid migration: Brent Sandstone, Heather Field, North Sea. Clay Miner. 24, 255–284.CrossRefGoogle Scholar
Glasmann, J.R., Larter, S., Briedis, N.A. & Lundegard, P.D. (1989b) Shale diagenesis in the Bergen High area, North Sea. Clays Clay Miner. 37, 97–112.CrossRefGoogle Scholar
Hamilton, P.J., Fallick, A.E., Macintyre, R.M. & Elliot, S. (1987) Isotopic tracing of the provenance and diagenesis of Lower Brent Group sands, North Seal, Pp. 939–949 in: Petroleum Geology of North West Europe (Brooks, J. & Glennie, K., editors). Graham & Trotman, London.Google Scholar
Hamilton, P.J., Kelley, S. & Fallick, A.E. (1989) K-Ar dating of illite in hydrocarbon reservoirs. Clay Miner. 24, 215–231.CrossRefGoogle Scholar
Kantorowicz, J.D. (1990) The influence of variations in illite morphology on the permeability of Middle Jurassic Brent Group sandstones, Cormorant Field, UK North Sea. Mar. Petrol. Geol. 7, 66–74.CrossRefGoogle Scholar
Lanson, B. (1990) Mise en evidence des mecanismes de transformation des interstratifies illite/smectite au cours de las diageneses. These de Doctorat de l'universite Paris-6, Paris, France.Google Scholar
Lanson, B. & Besson, G. (1992) Characterization of the end of smectite-to-illite transformation: decomposition of X-ray patterns. Clays Clay Miner. 40, 40–52.CrossRefGoogle Scholar
Lanson, B. & Champion, D. (1991) The I/S-to-lllite reaction in the late stage of diagenesis. Am. J. Sci. 291, 473–506.CrossRefGoogle Scholar
Lee, M., Aronson, J.L. & Savin, S.M. (1985) K/Ar dating of time of gas emplacement in Rotliegends Sandstones, Netherlands. Am. Assoc. Petrol. Gol. Bull. 690, 1381–1385.Google Scholar
Lee, M., Aronson, J.L. & Savin, S.M. (1989) Timing and conditions of Permian Rotliegends Sandstone Diagnesis, Southern North Sea: K/Ar and oxygen isotopic data. Am. Assoc. Petrol. Geol. Bull. 73, 195–215.Google Scholar
Liewig, N., Clauer, N. & Sommer, F. (1987) Rb-Sr and K-Ar dating of clay diagenesis in Jurassic sandstone oil reservoir, North Sea. Am. Assoc. Pet. Geol. Bull. 71, 1467–1474.Google Scholar
Morton, J.P. (1985) Rb-Sr evidence for punctuated illite/smectite diagenesis in the Oligocene Frio Formation, Texas Gulf Coast. Geol. Soc. Am. Bull. 96, 114–122.2.0.CO;2>CrossRefGoogle Scholar
Mossmann, J.R., Clauer, N. & Liewig, N. (1992) Dating thermal anomalies in sedimentary basins: the diagenetic history of clay minerals in the Triassic sandstones of the Paris Basin, France. Clay Miner. 27, 211–226.CrossRefGoogle Scholar
Newman, A.C.D. & Brown, G. (1987) The chemical constitution of clays. Pp. 1–128 in: Chemistry of Clays and Clay Minerals (Newman, A.C.D., editor). Mineralogical Society, London.Google 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, NH 03755, USA.Google Scholar
Scotchman, I.C., Jones, L.H. & Miller, R.S. (1989) Clay diagenesis and oil migration in Brent sandstones of NW Hutton Field, UK, North Sea. Clay Miner. 24, 339–374.CrossRefGoogle Scholar
Środoń, J., Elsass, F., Mchardy, W.J. & Morgan, D.J. (1992) Chemistry of illite-smectite inferred from TEM measurements of fundamental particles. Clay Miner. 27, 137–158.CrossRefGoogle Scholar
Thomas, M. (1986) Diagenetic sequences and K-Ar dating in Jurassic sandstones, Central Viking Graben: effects on reservoir properties. Clay Miner. 21, 695–710.CrossRefGoogle Scholar