Evidence for a lost ocean in Variscan terranes of the western Massif Central, France

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Abstract

Plate tectonics is now commonly invoked to explain the Variscan orogeny1–3, but only the presence of ophiolites can provide real evidence for an early Variscan ocean. None has been described so far in south-western Europe, with the possible exception of a few scattered lenses4 within the low-grade Moeche unit in Cabo-Ortegal, Spain, and the Chamrousse ophiolite5,6, French Alps, which displays no clear relationships to documented Variscan terranes. To fill this gap, eclogites with mid-ocean-ridge-basalt (MORB) compositions have been tentatively ascribed to an oceanic origin7, and various serpentinites and amphibolites have been inferred to derive from ophiolites1–3, but many geologists are still reluctant to admit that the Variscan orogeny resulted from the closure of a true ocean. Here we describe the remains of an ophiolite found in high-grade crystalline rocks in the European Variscan fold belt, in Limousin, western French Massif Central. This ophiolite comprises diopside-bearing harzburgites, depleted harzburgites, dunites, wehrlites and MORB-type gabbros and has structural, petrological and geochemical characteristics typical of oceanic lithosphere, thereby providing evidence for a lower Palaeozoic ocean.

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References

  1. 1

    Burg, J.-P. & Matte, P. Z. Dt. Geol. Ges. 129, 429–460 (1978).

  2. 2

    Matte, P. Tectonophysics 126, 329–374 (1986).

  3. 3

    Burg, J.-P., Bale, P., Brun, J.-P. & Girareau, J. Geodinamica Acta 1, 71–87 (1987).

  4. 4

    Arenas, R. et al. Hercinica 7 (in the press).

  5. 5

    Bodinier, J. L., Dupuy, C., Dostal, J. & Carme, F. Contr. Miner. Petrol. 78, 379–388 (1981).

  6. 6

    Ménot, R. P., Peucat, J. J., Scarenzi, D. & Piboule, Earth planet. Sci. Lett. 88, 82–92 (1988).

  7. 7

    Montigny, R. & Allègre, C. J. C.R. Acad. Sci. Paris, 279D, 543–545 (1974).

  8. 8

    Floc'h, J.-P. thesis, Univ. Limoges (1983).

  9. 9

    Girardeau, J., Dubuisson, G. & Mercier, J.-C. C. Bull. Soc. geol. France 8 (II), 849–860 (1986).

  10. 10

    Dubuisson, G., Hirn, A., Girardeau, J., Mercier, J.-C. C. & Veinante, J.-L. Tectonophysics 147, 19–31 (1987).

  11. 11

    Chenevoy, M., Forestier, F. H. & Gay, M. C.R. Carte géol. France (Bureau de Recherche Geologique et Minière, Orléans, France, 1962).

  12. 12

    Santallier, D. thesis, Univ. Orléans (1981).

  13. 13

    Lafon, J.-M. thesis, Univ. Montpellier (1986).

  14. 14

    Mercier, J.-C. C. J. geophys. Res. 85, 6293–6303 (1980).

  15. 15

    Mercier, J.-C. C. in Preferred orientation of minerals and rocks: an introduction to modern textural analysis (ed. Wenk, H. R.) 407–430 (Academic, New York, 1985).

  16. 16

    Bertrand, P. & Mercier, J.-C. C. Earth planet. Sci. Lett. 76, 109–122 (1985).

  17. 17

    Mercier, J.-C. C., Benoit, V. & Girardeau, J. Contr. Miner. Petrol. 85, 391–403 (1984).

  18. 18

    Kornprobst, J., Vidal, Ph. & Malod, J. C.R. Acad. Sci. Paris 306, Sér. II, 1359–1364 (1988).

  19. 19

    Prinzhofer, A. thesis, IPGP & Univ. Paris (1987).

  20. 20

    Cabanis, B. et al. Bull. Soc. geol. France 1 (XXV), 563–574 (1983).

  21. 21

    Nicolas, A. et al. Nature 294, 414–417 (1981).

  22. 22

    Lafon, J.-M. & Lancelot, J. R. Terra Cognita 6, 156 (1986).

  23. 23

    Girardeau, J., Mercier, J.-C. C. & Zao Yougong Tectonophysics 119, 407–433 (1986).

  24. 24

    Nicolas, A. Rev. Geophys. 24 (4), 875–895 (1986).

  25. 25

    Boudier, F. & Nicolas, A. Earth planet. Sci. Lett. 76, 84–92 (1985).

  26. 26

    Lemoine, M., Tricart, P. & Boillot, G. Geology 15, 622–625 (1987).

  27. 27

    Bernard-Griffiths, J. A. Fac. Sci. Univ. Clermont 55 (27), 243 (1975).

  28. 28

    Ducrot, J., Lancelot, J.-R. & Marchand, J. Earth planet. Sci. Lett. 62, 385–394 (1983).

  29. 29

    Peucat, J.J., Vidal, Ph., Godard, G. & Postaire, B. Earth planet. Sci. Lett. 60, 70–78 (1982).

  30. 30

    Ballard, J.F., Brun, J.-P. & Durand, J. C.R. Acad. Sci. Paris 303, 1227–1232 (1986).

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