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Mineralium Deposita

, Volume 19, Issue 4, pp 249–255 | Cite as

Isotopic composition of phanerozoic ore leads from the Swedish segment of the Fennoscandian Shield

  • Åke Johansson
  • David Rickard
Article

Abstract

95 analyses of ore lead isotope ratios from 23 Phanerozoic ore deposits from the Swedish segment of the Fennoscandian Shield form a marked linear trend on a 207Pb/204Pb versus 206Pb/204Pb diagram. The line may be interpreted in a two-stage model, the lead being derived from 1.8±0.15 Ga old Svecokarelian basement and mineralization occurring at 0.4±0.15 Ga. The initial composition of the Svecokarelian rock lead was similar to the lead in early Proterozoic volcanogenic sulfide ores in Sweden. — The large spread in the isotope ratios was caused by a combination of selective leaching of different minerals in the source rocks, mixing with less radiogenic Caledonian lead, and local or regional variations in the U, Th and Pb contents of the basement. As a consequence, conventional methods of identifying source rocks from lead isotopic data (e.g. mu-values, Th/U ratios) may not be directly applicable. Phanerozoic ore lead development in the Swedish section of the Fennoscandian Shield was ensialic. That is, the ore lead was almost entirely derived from the Precambrian basement, although this basement does not appear to be anomalously enriched in Pb. No juvenile or mantle lead was apparently contributed to this section of the crust after the Precambrian, except for that mechanically transported onto the western edge of the Shield by the Caledonian nappes. However, some of Europe's largest lead deposits are included in these Swedish Phanerozoic mineralizations, suggesting that it was the nature of the processes involved rather than the richness of the source, that determined their formation.

Keywords

Isotope Ratio Source Rock Lead Isotope Lead Development Precambrian Basement 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Björlykke, A., Sangster, D.F.: An overview of sandstone lead deposits and their relation to red-bed copper and carbonatehosted lead-zinc deposits. Econ. Geol. 75th anniversary volume, 179–213 (1981)Google Scholar
  2. Björlykke, A., Thorpe, R.I.: The source of lead in the Osen sandstone lead deposit on the Baltic Shield, Norway. Econ. Geol. 77:430–440 (1982)Google Scholar
  3. Christofferson, H.C., Wallin, B., Selkman, S., Rickard, D.T.: Mineralization controls in the sandstone lead-zinc deposit at Vassbo, Sweden. Econ. Geol. 74:1239–1249 (1979)Google Scholar
  4. Grip, E.: The lead deposits of the eastern border of the Caledonides in Sweden. Int. Geol. Congr., XXI Session, Part XVI, 149–159 (1960)Google Scholar
  5. Grip, E.: On the genesis of the lead ores of the eastern border of the Caledonides in Scandinavia. Econ. Geol. Monograph 3:208–218 (1967)Google Scholar
  6. Grip, E.: Sulfidmalm i fjällkedjan och i det baltiska kambriska flackhavsområdet. In: Malm i Sverige 2, Norra Sverige, E. Grip and R. Frietsch, pp. 10–66. Stockholm: Almqvist & Wiksell 1973Google Scholar
  7. Grip, E.: Sweden. In: Mineral deposits of Europe, Vol. I, Northwest Europe, S.H.U. Bowie, A. Kvalheim, H.W. Haslam, Eds., pp. 93–198. London: The Institution of Mining and Metallurgy and The Mineralogical Society, 1978Google Scholar
  8. Johansson, Å.: Occurrence and deformation of some sulphide-bearing quartz veins in the Nasafjället area, Swedish Caledonides. Norges Geol. Unders. 360:113–122 (1980)Google Scholar
  9. Johansson, Å.: Isotopic composition of lead from the Boda and Sollerön deposits, Siljan Ring area, Central Sweden. In: ORG 81 — Annual Report of the Ore Research Group, Stockholm University, D.T. Rickard, Ed., pp. 199–218. Stockholm, 1981Google Scholar
  10. Johansson, Å.: Descriptions of Caledonian sulfide-bearing veins in Sweden. In: ORG 83 — Annual Report of the Ore Research Group, Stockholm University, S. Lindblom, Ed., pp. 151–166. Stockholm, 1983aGoogle Scholar
  11. Johansson, Å.: Lead isotope composition of Caledonian sulfide-bearing veins in Sweden. Econ. Geol. 78:1674–1688 (1983b)Google Scholar
  12. Johansson, Å., Rickard, D.T.: The Variscan lead-zinc-fluorite veins of southern Sweden. Bull. du BRGM (2) II 2, 133–142 (1982)Google Scholar
  13. Johansson, Å., Rickard, D.T.: Some new lead isotope determinations from the Proterozoic sulfide ores of central Sweden. Mineral. Deposita (in press)Google Scholar
  14. Lundqvist, Th.: The Precambrian of Sweden. Sver. Geol. Unders. Ser. C no. 768:1–87 (1979)Google Scholar
  15. Moorbath, S., Vokes, F.M.: Lead isotope abundance studies on galena occurrences in Norway. Norsk Geol. Tidsskr. 43:283–343 (1963)Google Scholar
  16. Rickard, D.T., Willdén, M.Y., Marinder, N.-E., Donnelly, T.H.: Studies on the genesis of the Laisvall sandstone lead-zinc deposit, Sweden. Econ. Geol. 74:1255–1285 (1979)Google Scholar
  17. Rickard, D.T., Coleman, M., Swainbank, I.: Lead and sulfur isotopic compositions of galena from the Laisvall sandstone lead-zinc deposit, Sweden. Econ. Geol. 76:2042–2046 (1981)Google Scholar
  18. Rickard, D.T., Svensson, S.-Å.: Ore lead isotope variations in the Proterozoic massive pyrite deposit at Näsliden, Skellefte district, Sweden. Mineral. Deposita 19, No. 2: 145–151 (1984)Google Scholar
  19. Rickard, D.T., Wallin, B.: Geochemistry of the Vassbo sandstone lead deposit. (in preparation)Google Scholar
  20. Schweda, P.: Preliminary report on the isotopic composition of ore lead in the Pb-Zn deposits of the Dorotea district, central Swedish Caledonides. In: ORG 83 — Annual Report of the Ore Research Group, Stockholm University, S. Lindblom, Ed., pp. 53–59. Stockholm, 1983Google Scholar
  21. Stacey, J.S., Kramers, J.D.: Approximation of terrestrial lead isotope evolution by a two-stage model. Earth Planet. Sci. Lett. 26:207–221 (1975)Google Scholar
  22. Sundblad, K., Stephens, M.B.: Lead isotope systematics of stratabound sulphide deposits in the higher nappe complexes of the Swedish Caledonides. Econ. Geol. 78:1090–1107 (1983)Google Scholar
  23. Tegengren, F.R.: Vassbo blymalmsfyndighet i Idre och dess geologiska intramming. Srev. Geol. Unders. Ser. C no. 586:1–61 (1962)Google Scholar
  24. Wedepohl, K.H.: Lead: abundance in common magmatic rock types; crustal abundance. In: Handbook of geochemistry, K.H. Wedepohl, Ed., Vol. II-5, section 82-E. Berlin-Heidelberg-New York: Springer 1974Google Scholar
  25. Welin, E.: Till kännedomen om sulfidmalmerna och de zonerade zinkbländena i Boda och Solleröns kommuner, Kopparbergs län. Geol. Fören. Stockh. Förh. 81:495–513 (1959)Google Scholar
  26. Wickman, F.E.: Displacements of the Siljan ring structure. Geografiska Annaler 63A:313–317 (1981)Google Scholar
  27. Wickman, F.E., Blomqvist, N.G., Geijer, P., Parwel, A., von Ubisch, H., Welin, E.: Isotopic constitution of ore lead in Sweden. Ark. Mineral. Geol. 3(11):193–257 (1963)Google Scholar
  28. Williamson, J.H.: Least squares fitting of a straight line. Can. J. Phys. 76:1845–1847 (1968)Google Scholar

Copyright information

© Springer-Verlag 1984

Authors and Affiliations

  • Åke Johansson
    • 1
  • David Rickard
    • 2
  1. 1.Ore Research Group, Geological InstitutionStockholm UniversityStockholmSweden
  2. 2.Department of Mineral ExploitationUniversity CollegeCardiffUK

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