Hostname: page-component-6bf8c574d5-gr6zb Total loading time: 0 Render date: 2025-02-20T14:53:08.983Z Has data issue: false hasContentIssue false
  • English
  • Français

Galena Crystallization and the Origin of Sulfur in the Oklo and Bangombé Natural Reactors: The Effects of a ca. 900 Ma Thermal Event

Published online by Cambridge University Press:  21 March 2011

Lena Zetterström  and
Torbjörn Sunde
Lena Zetterström
Affiliation:
Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden
Torbjörn Sunde
Affiliation:
Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden
Get access

Abstract

Galena in the ca. 1950 Ma old natural fossil fission reactors in Gabon crystallized sometime between 980 Ma and 750 Ma during a period of regional extension and the intrusion of a dolerite dyke swarm. The S isotopic composition of galena, containing radiogenic Pb from uraninite, gives information about the origin of the S. Results from ion microprobe analyses of galena from the reactor zones indicate that S mainly originates from the surrounding sediment. Galena in a thin, altered dolerite dyke also contains non-magmatic S. The presented data gives no positive evidence for the involvement of magmatic S during the ca. 900 Ma galena crystallisation, however, the possibility cannot be ruled out.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 663: Symposium – Scientific Basis for Nuclear Waste management XXIV , 2000 , 953
Copyright
Copyright © Materials Research Society 2001

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

REFERENCES

1. Ruffenach, J.-C., in Natural Fission Reactors, edited by IAEA (IAEA, Vienna, 1978) pp. 441–471.Google Scholar
2. Gauthier-Lafaye, F., Holliger, P. and Blanc, P.-L., Geochim. Cosmochim. Acta 60, 4831–4852 (1996).Google Scholar
3. Janeczek, J. and Ewing, R.C., Geochim. Cosmochim. Acta 59, 1917–1931 (1995).Google Scholar
4. Hidaka, H., Shinotsuka, K. and Holliger, P., Radiochim. Acta 63, 19–22 (1993).Google Scholar
5. Zetterström, L. and Jensen, K.A., GSA Abstracts with Programs 31(7), A–68, (1999).Google Scholar
6. Nielsen, H., in Lectures in Isotope Geology, edited by Jäger, E. and Hunziker, J.C., (Springer- Verlag, Berlin Heidelberg New York, 1979) pp.283–312.Google Scholar
7. Eldridge, C.S., Compston, W., Williams, I.S. and Walshe, J.L., U.S. Geol. Surv. Bull. 1890, 163–174 (1989).Google Scholar
8. Chaussidon, M., PhD. Thesis, Institut National Polytechnique de Lorraine, 1988.Google Scholar
9. Hoefs, J., Stable Isotope Geochemistry 4th ed.(Springer, Berlin Heidelberg, 1997) pp.60, 97–103.Google Scholar
10. Ohmoto, H. and Rye, R.O., in Geochemistry of hydrothermal ore deposits, edited by Barnes, H. L. (Rinehart and Winston, New York, 1979) pp.509–567.Google Scholar
11. Kakegawa, T. and Ohmoto, H., Precambrian Res. 96, 209–224 (1999).Google Scholar
12. Stetter, K.O., Huber, R., Bloechl, E., Kurr, M., Eden, R.D., Fielder, M., Cash, H. and Vance, I.S.O., Nature 365, 743–745 (1993).Google Scholar
13. Savary, V. and Pagel, M., in OKLO Working Group - Fourth joint EC-CEA progress and final meeting held in Saclay, France, on 22 and 23 June 1995, edited by Blanc, P.L. and Maravic, H.von, (Nuclear Science and Technology Report EUR 16704 EN), pp. 65–74 (1996).Google Scholar
14. Michaud, V. and Mathieu, R., CEA-DCC-DESD Rapport Technique 98/176 (1998)Google Scholar
15. Ohmoto, H., Econ. Geol. 67, 551–578 (1972).Google Scholar
16. Ludwig, K.R., Berkeley Geochronology Center Special Publication No.2 (1999).Google Scholar
17. Gauthier-Lafaye, F. and Weber, F., Econ. Geol. 84, 2267–2285 (1989).Google Scholar
18. Strauss, H., Precambrian Res. 63, 225–246 (1993)Google Scholar