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Combined Sr–O isotope relationships and petrogenesis of Andean volcanics of South America

Naturevolume 302pages814816 (1983) | Download Citation

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Abstract

Active andesitic-type volcanism in the southern Andes (lat. 42–36° S) is characterized by low Sr- and O-isotopic compositions which fall in the range 87Sr/86Sr = 0.7036–0.7043, δ18O = 5.2–6.8‰. In contrast, volcanic centres in the Central Andes (lat. 24–21° S) are significantly enriched in both 87Sr and 18O. We present the first combined Sr- and O-isotope study of the southern volcanic zone (SVZ) in Chile (crustal thickness <40 km)1 and of the southern part of the central volcanic zone (CVZ) in the borderlands of Bolivia, Chile and Argentina (crustal thickness 60–70 km)1. Only one of 13 volcanic centres studied (Lascar) exhibits a correlated increase in both 87Sr and 18O parallel with the basalt–andesite–rhyolite compositional change, indicative of contamination by upper crust through a fractional crystallization–assimilation mechanism. The other centres of the CVZ, for which there is an overall Sr–O correlation, document the variable contamination of mantle-derived magmas at depth in the lower crust which had been thickened by Mesozoic and earlier plutonism.

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References

  1. 1

    Cummings, D. & Schiller, G. I. Earth-Sci. Rev. 7, 97–125 (1971).

  2. 2

    Francis, P. W., Moorbath, S. & Thorpe, R. S. Earth planet. sci. Lett. 37, 197–202 (1977).

  3. 3

    Francis, P. W., Thorpe, R. S., Moorbath, S., Kretzschmar, G. A. & Hammill, M. Earth planet. sci. Lett. 48, 257–267 (1980).

  4. 4

    Magaritz, M., Whitford, D. J. & James, D. E. Earth planet. sci. Lett. 40, 220–230 (1978).

  5. 5

    Harmon, R. S., Thorpe, R. S. & Francis, P. W. Nature 290, 396–399 (1981).

  6. 6

    Briqueu, L. & Lancelot, J. R. Earth planet. sci. Lett. 43, 385–396 (1979).

  7. 7

    De Paolo, D. J. Earth planet. sci. Lett. 53, 189–202 (1981).

  8. 8

    James, D. E. Earth planet. sci. Lett. 57, 47–62 (1982).

  9. 9

    Thorpe, R. S. & Francis, P. W. Tectonophysics 57, 53–70 (1979).

  10. 10

    Coulon, C. & Thorpe, R. S. Tectonophysics 77, 79–93 (1981).

  11. 11

    Stern, C. R. & Futa, K. EOS 63, 456 (1982).

  12. 12

    Hickey, R. L., Frey, F. A., Lopez-Escobar, L. & Munizaga, F. Geol. Soc. Am. Abstr. (1982).

  13. 13

    Chivas, A. R., Andrews, A. S., Sinha, A. K. & O'Neil, J. R. Nature 300, 139–143 (1982).

  14. 14

    Taylor, H. P. Earth planet. sci. Lett. 47, 243–254 (1980).

  15. 15

    Klerkx, J., Deutsch, S., Pichler, H. & Zeil, W. J. Volcan. geotherm. Res. 2, 49–71 (1977).

  16. 16

    Hawkesworth, C. J. et al. Earth planet. sci. Lett. 42, 45–57 (1979).

  17. 17

    Tilton, G. R. & Barreiro, B. A. Science 210, 1245–1247 (1980).

  18. 18

    Hawkesworth, C. J., Hammill, M., Gledhill, A. R., Calstéren, P. & Rogers, G. Earth planet. sci. Lett. 58, 240–254 (1982).

  19. 19

    Thorpe, R. S. & Francis, P. S. Origin of Granite Bathotiths—Geochemical Evidence (eds Atherton, M. P. & Tarney, J.) 65–75 (Shiva, Orpington, 1979).

  20. 20

    Wyllie, P. J. Tectonophysics 43, 41–71 (1977).

  21. 21

    Wyllie, P. J. Geol. Rdsch. 70, 128–153 (1981).

  22. 22

    Hawkesworth, C. J. Origin of Granite Batholithsmdash;Geochemical Evidence (eds Atherton, M. P. & Tarney, J.) 76–89 (Shiva, Orpington, 1979).

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Affiliations

  1. Department of Earth Sciences, Faculty of Science, University of Yaounde, BP 812, Yaounde, Cameroun

    • Bernard Déruelle
  2. Department of Geological Sciences, Southern Methodist University, Dallas, Texas, 75275, USA

    • Russell S. Harmon
  3. Department of Geology and Mineralogy, Oxford University, Parks Road, Oxford, OX1 3PR, UK

    • Stephen Moorbath

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https://doi.org/10.1038/302814a0

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