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A Variscan slow-spreading ridge (MOR-LHOT) in Limousin (French Massif Central): magmatic evolution and tectonic setting inferred from mineral chemistry

Published online by Cambridge University Press:  05 July 2018

J. Berger ,
O. Féménias ,
J.C.C. Mercier  and
D. Demaiffe
J. Berger*
Affiliation:
Section de Géologie Isotopique, Africa Museum, Leuvensteenweg 13, B-3080 Tervuren, Belgium Laboratoire de Géologie Isotopique et Géodynamique Chimique, DSTE, Université Libre de Bruxelles (CP 160/02), 50 Avenue Roosevelt, B-1050 Brussels, Belgium
O. Féménias
Affiliation:
Laboratoire de Géologie Isotopique et Géodynamique Chimique, DSTE, Université Libre de Bruxelles (CP 160/02), 50 Avenue Roosevelt, B-1050 Brussels, Belgium
J.C.C. Mercier
Affiliation:
CLDG, Université de La Rochelle, av. Crépeau, F-17402 La Rochelle cedex 1, France
D. Demaiffe
Affiliation:
Laboratoire de Géologie Isotopique et Géodynamique Chimique, DSTE, Université Libre de Bruxelles (CP 160/02), 50 Avenue Roosevelt, B-1050 Brussels, Belgium
*
*E-mail: [email protected]
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Abstract

The Limousin ophiolite (French Massif Central) occurs as elongate bodies forming a (nearly) continuous suture zone between two major lithotectonic units of the French Variscan belt. The mantle section of the ophiolite is made of diopside-bearing harzburgite, harzburgite and dunite characteristic of a lherzolite-harzburgite ophiolite type (LHOT). The plutonic section is essentially composed of troctolites, wehrlites and gabbros locally intruded by ilmenite-rich mafic dykes. All the rocks were strongly affected by an ocean-floor hydrothermal metamorphism. The composition and evolution of primary magmatic phases (olivine, clinopyroxene, plagioclase and spinel) throughout the lowermost magmatic sequence correspond to those described in oceanic cumulates (ODP data). The Limousin ophiolite is thus of MOR type instead of SSZ type. The whole lithological section, the mineral chemistry, the extensive hydrothermal oceanic alteration and the relatively thin crustal section are typical of a slow-spreading ridge ocean (i.e. Mid-Atlantic ridge). Comparison of the Limousin ophiolite with other ophiolites from European Variscides suggests that the oceanic domain was actively spreading during the Late Palaeozoic and extended from the Armorican massif to the Polish Sudetes.

Keywords

LHOTMORslow-spreading ridgeVariscanLimousinFrance
Type
Research Article
Information
Mineralogical Magazine , Volume 70 , Issue 2 , April 2006 , pp. 175 - 185
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2006

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References

Beard, J.S. (1986) Characteristic mineralogy of arc-related cumulate gabbros: Implications for the tectonic setting of gabbroic plutons and for andesitegenesis. Geology, 14, 848–851.2.0.CO;2>CrossRefGoogle Scholar
Beard, B.L., Medaris, L.G., Johnson, C.M., Brueckner, H.K., Misar, Z. (1992) Petrogenesis of Variscan high-temperature Group A eclogites from the Moldanubian Zone of the Bohemian Massif, Czechoslovakia. Contributions to Mineralogy and Petrology, 111, 468–483.CrossRefGoogle Scholar
Berger, J., Féménias, O., Merrier, J.-C.C. and Demaiffe, D. (2005) Ocean-floor hydrothermal metamorphism in the Limousin ophiolite (Western French Massif Central): Evidence of a rare preserved Variscan oceanic marker. Journal of Metamorphic Geology, 23, 795–812.Google Scholar
Bosse, V., Feraud, G., Ruffet, G., Ballévre, M., Peucat, J.J. and De Jong, K. (2000) Late Devonian subduction and early-orogenic exhumation of eclo-gite-facies rocks from the Champtoceaux Complex (Variscan belt, France). Geological Journal, 35, 1–29.CrossRefGoogle Scholar
Brueckner, H.K., Medaris, L.G. and Bakun-Czubarov, N. (1991) Nd and Sr age and isotope pattern from Variscan eclogites of the eastern Bohemian massif. Neues Jahrbuch fiir Mineralogie Abhandlungen, 163, 169–196.Google Scholar
Burkhard, D.J.M. (1993) Accessory chromium spinels: their coexistence and alteration in serpentinites. Geochimica et Cosmochimica Acta, 57, 1297–1306.CrossRefGoogle Scholar
Cannat, M., Mevel, C. Maia, M., Deplus, C. Durand, C., Gente, P., Agrinier, P., Belarouchi, A., Dubuisson, G., Humler, E. and Reynolds, J. (1995) Thin crust, ultramafic exposures, and rugged faulting patterns at the Mid-Atlantic Ridge (22 degrees-24 degrees N). Geology, 23, 49–52 2.3.CO;2>CrossRefGoogle Scholar
Cannat, M., Chatin, F., Whitechurch, H. and Ceuleneer, G. (1997) Gabbroic rocks trapped in the upper mantle at Mid Atlantic ridge. Proceedings of the Ocean Drilling Program, Scientific Results, 153, 243–264.Google Scholar
Church, W.E. and Riccio, L. (1977) Fractionation trends in the Bay of islands ophiolite of Newfoundland: polycyclic cumulate sequences in ophiolites and their classifications. Canadian Journal of Earth Science, 14, 1156–1165.CrossRefGoogle Scholar
Dick, H.J.B. and Bullen, T. (1984) Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas. Contributions to Mineralogy and Petrology, 86, 54–76.CrossRefGoogle Scholar
Dubuisson, G. (1988) Etude d'un segment d'orogène ancien et de ses marqueurs ophiolitiques: approche tectonique, géophysique et pétrologique. Unpublished PhD thesis, Universite Paris VII, 323 pp.Google Scholar
Dubuisson, G., Him, A., Girardeau, J., Merrier, J.-C.C. and Veinante, J.L. (1988) Multiple Variscan nappes in Limousin, western Massif Central, France: geophysical constraints to the geological model and geodynamic implications. Tectonophysics, 147, 19–31.CrossRefGoogle Scholar
Dubuisson, G., Mercier, J.-C.C, Girardeau, J. and Frison, J.Y. (1989) Evidence for a lost ocean in Variscan terranes of the western Massif Central, France. Nature, 337, 729–732.CrossRefGoogle Scholar
Egal, E., Santallier, D., Maillet, N. and Piboule, M. (1985) Evolution métamorphique des lherzolites manteliques et des cumulats basiques et ultrabasi-ques en Limousin. Documents du BRGM, 95–3, 7–34.Google Scholar
Elthon, D., Stewart, M. and Ross, D.K. (1992) Compositional trends of minerals in oceanic cumulates. Journal of Geophysical Research, 97, 15189–15200.CrossRefGoogle Scholar
Faryad, S.W., Melcher, F., Hoinkes, G., Puhl, J., Meisel, T. and Frank, W. (2002) Relicts of eclogite-facies metamorphism in the Austroalpine basement Hochgrössen (Speik complex), Austria. Mineralogy and Petrology, 74, 49–73.Google Scholar
Gόmez-Pugnaire, M.T., Azor, A., Fernandez-Soler, J.M. and Lόpez Sánchez-Vizcaíno, V. (2003) The amphibolites from the Ossa-Morena/Central Iberian Variscan suture (Southwestern Iberian Massif): geochemistry and tectonic interpretation. Lithos, 68, 23–42.CrossRefGoogle Scholar
Hébert, R. and Laurent, R. (1990) Mineral chemistry of the plutonic section of the Troodos ophiolite: new constraints for genesis of arc-related ophiolites. Pp. 149–163 in: Ophiolites: Ocean Crustal Analogues(Malpas, J., Moores, E., Panayotiou, A., and Xenophontos, C., editors). Proceedings of the Troodos Ophiolite Symposium 1987, Ministry of Agriculture and Natural Resources, Nicosia.Google Scholar
Hébert, R., Serri, G. and Hekinian, R. (1989) Mineral chemistry of ultramafic tectonites and ultramafic to gabbroic cumulates from the major oceanic basins and Northern Apennines ophiolites (Italy) – A comparison. Chemical Geology, 77, 183–208.CrossRefGoogle Scholar
Kalt, A., Hanel, M., Schleicher, H. and Kramm, U. (1994) Petrology and geochronology of eclogites from the Variscan Schwarzwald (F.R.G.). Contributions to Mineralogy and Petrology, 115, 287–302.CrossRefGoogle Scholar
Lafon, J.M. (1986) Geochronologie U-Pb appliquee a deux segments du Massif Central franqais: le Rouerge oriental et le Limousin central. Unpublished PhD thesis, Universite de Montpellier, France 152 pp.Google Scholar
Ledru, P., Lardeaux, J.M., Santallier, D., Autran, A., Quenardel, J.M., Floc'h, J.-P., Lerouge, G., Maillet, N., Marchand, J. and Ploquin, A. (1989) Ou sont les nappes dans le Massif Central francais. Bulletin de la Societe Geologique de France, 8, 605–618.CrossRefGoogle Scholar
Leloix, C., Faure, M. and Feybesse, J-L. (1999) Hercynian polyphase tectonics in north-east French Massif Central: the closure of the Brevenne Devonian-Dinantian rift. International Journal of Earth Sciences, 88, 409–421.CrossRefGoogle Scholar
Malpas, J. (1990) Crustal accretionary processes in the Troodos ophiolite, Cyprus: evidence from field mapping and deep crustal drilling. Pp. 65–74.in. Ophiolites: Ocean Crustal Analogues(Malpas, J., Moores, E., Panayotiou, A., and Xenophontos, C., editors). Proceedings of the Troodos Ophiolite Symposium 1987, Ministry of Agriculture and Natural Resources, Nicosia.Google Scholar
Matte, P. (2001) The Variscan collage and orogeny (480-290 Ma) and the tectonic definition of the Armorica microplate: a review. Terra Nova, 13, 122–128.CrossRefGoogle Scholar
Medaris, G., Ducea, M., Ghent, E. and Iancu, V. (2003) Conditions and timing of high-pressure Variscan metamorphism in the South Carpathians, Romania. Lithos, 70, 141–161.CrossRefGoogle Scholar
Ménot, R.P., Peucat, J.J., Scarenzi, D. and Piboule, M. (1988) 496 My age of plagiogranites in the Chamrousse ophiolite complex (external crystalline massifs in the French Alps): evidence of a Lower Paleozoic oceanization. Earth and Planetary Science Letters, 88, 82–92.CrossRefGoogle Scholar
Miller, C. and Thoni, M. (1995) Origin of eclogites from the Autroalpine Otztal Basement (Tirol, Austria): geochemistry and Sm-Nd vs Rb-Sr isotope systema-tics. Chemical Geology, 122, 199–225.CrossRefGoogle Scholar
Miyashiro, A. (1975) Classification, characteristics and origin of ophiolites. Journal of Geology, 83, 249–281.CrossRefGoogle Scholar
Nicolas, A. and Boudier, F. (2003) Where ophiolites come from and what they tell us. Pp. 137–152.in: Ophiolite Concept and the Evolution of Geological Thought(Dilek, Y. and Newcomb, S., S. editors). Special Paper, 373, Geological Society of America, Boulder, Colorado.Google Scholar
Niu, Y., Gilmore, T., Mackie, S., Greig, A. and Bach, W. (2002) Mineral chemistry, whole-rock compositions, and petrogenesis of Leg 176 gabbros: data and discussion. Proceedings of the Ocean Drilling Program, Scientific Results, 176, 1–56.Google Scholar
Ordéñez Casado, B., Gebauer, D., Schaffer, H.J., Ibarguchi, J.I.G. and Peucat, JJ. (2001) A single Devonian subduction event for the HP-HT metamorphism of the Cabo Ortegal complex within the Iberian Massif. Tectonophysics, 332, 359–385.CrossRefGoogle Scholar
Paquette, J.L., Monchoux, P. and Couturier, M. (1995) Geochemical and isotopic study of a norite–eclogite transition in European Variscan belt: implications for U-Pb zircon systematics in metabasic rocks. Geochimica et Cosmochimica Acta, 56, 1611–1622.CrossRefGoogle Scholar
Parlak, O., Höck, V. and Delaloye, M. (2002) The supra-subduction zone Pozanti-Karsanti ophiolite, southern Turkey: evidence for high pressure crystal fractiona-tion of ultramafic cumulates. Lithos, 65, 205–221.CrossRefGoogle Scholar
Pearce, J.A. (2003) Supra-subduction zone ophiolites: the search for modern analogues. Pp. 269–293 in. Ophiolite Concept and the Evolution of Geological Thought(Dilek, Y. and Newcomb, S., S. editors). Special Paper, 373, Geological Society of America, Boulder, Colorado.Google Scholar
Pin, C. (1990) Variscan oceans: ages origins and geodynamic implications inferred from geochemical and radiometric data. Tectonophysics, 177, 215–227.CrossRefGoogle Scholar
Pin, C. and Carme, F. (1987) A Sm-Nd isotopic study of 500Ma old oceanic crust in the Variscan belt of Western Europe: the Chamrousse ophiolite complex, Western Alps (France). Contributions to Mineralogy and Petrology, 96, 406–413.CrossRefGoogle Scholar
Pin, C. and Paquette, J.L. (2002) Sr-Nd isotope and trace element evidence for a late Devonian active margin in northern Massif Central (France). Geodynamica Acta, 15, 63–77.Google Scholar
Pin, C. and Peucat, J.J. (1986) Ages des épisodes de métamorphisme paleozoi'ques dans le Massif Central et le Massif Armoricain. Bulletin de la Societe Géologique de France, 3, 461–469.CrossRefGoogle Scholar
Pin, C., Majerowicz, A. and Wojciechowska, I. (1988) Upper Paleozoic oceanic crust in the Polish Sudetes: Nd-Sr isotope and trace elements evidence. Lithos, 21, 195–209.CrossRefGoogle Scholar
Rodríguez, J., Cosca, M.A., Gil Ibarguchi, J.I. and Dallmeyer, R.D. (2003) Strain partitioning and preservation of 40Ar/39Ar ages during Variscan exhumation of a subducted crust (Malpica–Tui complex, NW Spain). Lithos, 70, 111–139.CrossRefGoogle Scholar
Santallier, D. (1995) A reply: another way of considering the ophiolite question. Pp. 354–358 in: Pre-Mesozoic Geology in France and Related Area. (Keppie, J.D., editor). Springer Verlag, Berlin.Google Scholar
Schaltegger, U., Gebauer, D. and von Quadt, A. (2002) The mafic-ultramafic rock association of Loderio-Biasca (lower Pennine nappes, Ticino, Switzerland): Cambrian oceanic magmatism and its bearing on early Paleozoic paleogeography. Chemical Geology, 186, 265–279.CrossRefGoogle Scholar
Schmídicke, E., Mezger, K., Cosca, M.A. and Okrusch, M. (1995) Variscan Sm-Nd and Ar-Ar ages of eclogite facies rocks from the Erzgebirge, Bohemian Massif. Journal of Metamorphic Geology, 13, 537–552.CrossRefGoogle Scholar
Serri, G. (1981) The petrochemistry of ophiolitic gabbroic complexes: a key for the classification of ophiolites into low-Ti and high-Ti types. Earth and Planetary Science Letters, 52, 203–212.CrossRefGoogle Scholar
Sisson, T.W. and Grove, T.L. (1993) Experimental investigations of the role of H2O in calc-alkaline differentiation and subduction zone magmatism. Contributions to Mineralogy and Petrology, 113, 143–166.CrossRefGoogle Scholar
Stosch, H.G. and Langmuir, G.W. (1990) Geochemistry and evolution of MORB-type eclogites from the Münchberg Massif, southern Germany. Earth and Planetary Science Letters, 99, 230–249.CrossRefGoogle Scholar
Svojtka, M., Kosler, J. and Venera, Z. (2002) Dating granulite-facies structures and the exhumation of lower crust in the Moldanubian Zone of the Bohemian Massif. International Journal of Earth Sciences, 91, 373–385.CrossRefGoogle Scholar
von Quadt, A. and Gebauer, D. (1993) Sm-Nd and U-Pb dating of eclogites and granulites from the Oberpfalz, NE Bavaria, Germany. Chemical Geology, 109, 317–339.CrossRefGoogle Scholar
von Raumer, J.F., Stampfli, G.M., Borel, G. and Bussy, F. (2002) Organization of pre-Variscan basement areas at the north-Gondwana margin. International Journal of Earth Sciences, 91, 35–52.CrossRefGoogle Scholar