Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-30T21:38:23.189Z Has data issue: false hasContentIssue false

Modelling of chalk diagenesis (Eldfisk Field, Norwegian North Sea) using whole rock and laser ablation stable isotopic data

Published online by Cambridge University Press:  01 May 2009

R. G. Maliva
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, United Kingdom
J. A. D. Dickson
Affiliation:
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, United Kingdom
A. Råheim
Affiliation:
Institute for Energy Technology, P.O. Box 40, 2007 Kjeller, Norway

Abstract

Laser ablation techniques permit the determination of the stable isotopic ratios of finely crystalline calcite cements in chalks for the first time. Modelling of fluid–rock interaction using whole rock and laser ablation stable isotopic data indicates that carbonate mineral diagenesis in the Eldfisk Field consisted largely of the dissolution and reprecipitation of calcite with little associated loss of porosity. Cementation by calcite derived from stylolites apparently occurred throughout the Eldfisk Field chalk, but had only a subsidiary effect on whole rock isotopic ratios. Oxygen isotopic data indicates a pore water temperature of 50–80 °C during the bulk of chalk recrystallization. Increases in whole rock δ13C values with depth are likely the result of bacterial methanogenesis during chalk recrystallization.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1991

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

Banner, J. L., Hanson, G. N. & Meyers, W. J. 1988. Water–rock interaction history of regionally extensive dolomites of the Burlington-Keokuk Formation (Mississippian): isotope evidence. In Sedimentology and Geochemistry of Dolostones (eds Shukla, V. and Baker, P. A.), pp. 97113. Tulsa: Society of Economic Paleontologists and Mineralogists, Special Publication 43.CrossRefGoogle Scholar
Brewster, J. & Dangerfield, J. A. 1984. Chalk fields along the Lindesnes Ridge, Eldfisk. Marine and Petroleum Geology 1, 239–78.CrossRefGoogle Scholar
Buchardt, B. & Jorgensen, N. O. 1979. Stable isotope variations at the Cretaceous/Tertiary boundary in Denmark. In Cretaceous/Tertiary Boundary Events Symposium. II. Proceedings (ed. Christensen, W. K. and Birkelund, T.), pp. 5461. University of Copenhagen.Google Scholar
Carothers, W. W. & Kharaka, Y. K. 1978. Aliphatic acid anions in oil field waters – implications for the origin of natural gas. American Association of Petroleum Geologists Bulletin 62, 2441–53.Google Scholar
Carothers, W. W. & Kharaka, Y. K. 1980. Stable carbon isotopes of HCO3 in oilfield waters – implications for the origin of CO2. Geochimica et Cosmochimica Acta 44, 323–32.CrossRefGoogle Scholar
D'Heur, M. 1984. Porosity and hydrocarbon distribution in North Sea chalk reservoirs. Marine and Petroleum Geology 1, 211–37.CrossRefGoogle Scholar
Fischer, A. G. & Arthur, M. A. 1977. Secular variations in the pelagic realm. In Deep-water Carbonate Environments (ed. Cook, H. E. and Enos, P.), pp. 1950. Tulsa: Society of Economic Paleontologists and Mineralogists, Special Publication 25.CrossRefGoogle Scholar
Hancock, J. M. & Scholle, P. A. 1975. Chalk of the North Sea. In Petroleum and the Continental Shelf of NorthWest Europe, vol. 1 (ed. Woodward, A. W.), pp. 413–25, New York: Wiley & Sons.Google Scholar
Jensenius, J. & Munksgaard, N. C. 1989. Large scale hot water migration around salt diapirs in the Danish Central Trough and their impact on diagenesis of chalk reservoirs. Geochimica et Cosmochimica Acta 52, 988.Google Scholar
Jorgensen, N. O. 1987. Oxygen and carbon isotopic composition of Upper Cretaceous chalk from the Danish sub-basin and the North Sea Central Graben. Sedimentology 34, 559–70.CrossRefGoogle Scholar
Land, L. S. 1980. The isotopic and trace element geochemistry of dolomite: The state of the art. In Concepts and Models of Dolomitization (ed. Zenger, D. H., Dunham, J. B. and Ethington, R. L.), pp. 87110. Tulsa: Society of Economic Paleontologists and Mineralogists, Special Publication 28.CrossRefGoogle Scholar
Lawerence, J. R. 1973. Interstitial water studies, Leg 15 – Stable oxygen and carbon isotope variations in water, carbonates, and silicates from the Venezuela Basin (Site 149) and the Aves Rise (Site 148). Initial Reports of the Deep Sea Drilling Project 20, 891–9.Google Scholar
Michaud, F. 1987. Eldfisk. In Geology of the Norwegian Oil and Gas Fields (ed. Spencer, A. H. et al. ), pp 89105. London: Graham & Trotman.Google Scholar
O'Neil, J. R., Clayton, R. N. & Mayeda, T. D. 1969. Oxygen isotope fractionation in divalent metal carbonates. Journal of Chemical Physics 51, 5547–8.CrossRefGoogle Scholar
Savin, S. 1977. The history of the Earth's surface temperature during the past 100 million years. Annual Review of Earth and Planetary Science 5, 319–55.CrossRefGoogle Scholar
Scholle, P. A. 1977. Chalk diagenesis and its relation to petroleum exploration: Oil from chalks, a modern miracle. American Association of Petroleum Geologists Bulletin 61, 9821009.Google Scholar
Scholle, P. A. & Arthur, M. A. 1980. Carbon isotope fluctuations in Cretaceous pelagic limestones: potential stratigraphic and petroleum exploration tool. American Association of Petroleum Geologists Bulletin 64, 6787.Google Scholar
Smalley, P. C, Stijfthoorn, D. E., Råheim, A., Johansen, H. & Dickson, J. A. D. 1989. The laser microprobe and its application to the study of C and O isotopes in calcite and aragonite. Sedimentary Geology 65, 211–22.CrossRefGoogle Scholar
Taylor, H. P. 1979. Oxygen and hydrogen isotope relationships in hydrothermal mineral deposits. In Geochemistry of Hydrothermal Ore Deposits, 2nd ed. (ed. Barnes, H. L.), pp. 236–77. New York: Wiley & Sons.Google Scholar
Taylor, S. R. & Lapre, J. F. 1987. North Sea chalk diagenesis: its effect on reservoir location and properties. In Petroleum Geology of North West Europe (ed. Brooks, J. and Glennie, K.), pp. 483–95, London: Graham & Trotman.Google Scholar