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U-Pb zircon, Rb-Sr and Sm-Nd geochronology of high- to very-high-pressure meta-acidic rocks from the western Alps

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Abstract

Three meta-acidic rocks from the western Italian Alps, a magnesiochloritoid-bearing “metapelite” from the Monte Rosa massif, a coesite-pyrope-“quartzite” from the Dora Maira massif and the Monte Mucrone granite in the Sesia Zone, have been studied by U-Pb zircon, Rb-Sr on whole-rock, apatite and phengite and Sm-Nd wholerock methods. The mineral parageneses of the investigated rocks indicate high- to very-high-pressure and medium-to-high-temperature metamorphism. This combined isotopic study has enabled us to constrain the ages of magmatic and metamorphic events and also to compare the behaviour of U-Pb zircon systems in three intensely metamorphosed areas of the Pennine domain. The U-Pb zircon data have yielded a magmatic age for the Monte Mucrone granite at 286±2 Ma. This result confirms the occurence of late-Hercynian magmatism in the Sesia Zone, as in other Austro-Alpine units and in other areas of the European crystalline basement. In the Monte Rosa massif, a geologically meaningless lower intercept age of 192±2 Ma has been interpreted as an artefact due to a complex evolution of the U-Pb zircon system. The magmatic shape of the zircons implies a magmatic or volcano-sedimentary protolith for this rock, originally considered as a metasediment. The very-high-pressure metamorphism in the Dora Maira “quartzite” has produced an opening of the U-Pb zircon system at 121+12−29 Ma. The Rb-Sr data support the occurence of high-grade metamorphism during Cretaceous times. Phengites model ages are slightly younger than the U-Pb zircon lower intercept ages due to cooling phenomena or possible response of the phengites to a later deformation. The Nd model ages from the whole-rock samples, as well as the U-Pb upper intercept ages from zircons of all three investigated rocks, indicate the presence of Proterozoic crustal components inherited from the precursors of these meta-acidic rocks. The studied zircon populations and their U-Pb systems apparently showed open-system behaviour only when affected by extreme metamorphic conditions (700–750° C, > 28 kbar), whereas eclogite-facies conditions of 500–550° C and 14–16 kbar were not enough to disturb significantly the U-Pb zircon evolution. It is also probable that the sedimentary or magmatic origin of the protoliths of these meta-acidic rocks, which involved different characteristics such as grain-size and fluid phase concentration and composition, could be another important factor controlling the U-Pb zircon system behaviour during metamorphic events.

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References

  • Bearth P (1952) Geologie und Petrographie der Monte-Rosa. Beitr Geol Karte Schweiz, NF 96, 94

  • Bernard-Griffiths J, Peucat JJ, Sheppard S, Vidal P (1985) Petrogenesis of Hercynian leucogranites from the southern Armorican Massif: contribution of REE and isotopic (Sr, Nd, Pb and O) geochemical data to the study of source rock characteristics and ages. Earth Planet Sci Lett 74:235–250

    Google Scholar 

  • Chappell BW, White AJR (1974) Two contrasting granite types. Pacific Geology 8:173–174

    Google Scholar 

  • Chopin C (1984) Coesite and pure pyrope in high-grade blueschists of the western Alps: a first record and some consequences. Contrib Mineral Petrol 86:107–118

    Google Scholar 

  • Chopin C (1986) Phase relationships of ellenbergerite, a new highpressure Mg-Al-Ti silicate in coesite-pyrope-quartzite from the western Alps. In Blueschists and related eclogites. In: BW Evans, EH Brown (ed) Geol Soc Am Mem 164:31–42

  • Chopin C (1987) Very-high-pressure metamorphism in the western Alps: implications for subduction of continental crust. Phil Trans R Soc Lond A321:183–197

    Google Scholar 

  • Chopin C, Maluski H (1980) 40Ar-39Ar dating of high-pressure metamorphic micas from the Gran Paradiso area (Western Alps): evidence against the blocking temperature concept. Contrib Mineral Petrol 74:391–394

    Google Scholar 

  • Chopin C, Monié P (1984) A unique magnesiochloritoid-bearing high-pressure assemblage from the Monte-Rosa, western Alps: petrologic and 40Ar-39Ar radiometric study. Contrib Mineral Petrol 87:388–398

    Google Scholar 

  • Chopin C, Klaska R, Medenbach O, Dron D (1985) Ellenbergerite a new high-pressure Mg-Al(Ti-Zr)-silicate with a novel structure based on face-sharing octahedra. Contrib Mineral Petrol 92:316–321

    Google Scholar 

  • Cliff RA (1981) Pre-Alpine history in the Pennine zone in the Tauern Window, Austria, U-Pb and Rb-Sr geochronology. Contrib Mineral Petrol 77:262–266

    Google Scholar 

  • Cocherie A, Rossi P, Le Bel L (1984) The Variscan calc-alkalic plutonism of western Corsica: mineralogy and major and trace element chemistry. Phys Earth Planet Inter 35:145–178

    Google Scholar 

  • Compagnoni R, Maffeo B (1973) Jadeite-bearing metagranites and related rocks in the mount Mucrone area (Sesia-Lanzo zone, Western Italian Alps). Schweiz. Mineral Petrol Mitt 54:355–378

    Google Scholar 

  • Compagnoni R, Dal Piaz GV, Hunziker JC, Gosso G, Lombardo B, Williams PF (1977) The Sesia-Lanzo zone, a slice of continental crust with Alpine high-pressure-low-temperature assemblage in the Western Italian Alps. Rend Soc Ital Mineral Petrol 33:281–334

    Google Scholar 

  • Dal Piaz GV, Lombardo B (1986) Early eclogite metamorphism in the Penninic Monte-Rosa-Gran Paradiso basement nappes of the northwestern Alps. In blueschists and related eclogites. In: BW Evans, EH Brown (ed) Geol Soc Am Mem 164:249–265

  • Dumont T, Lemoine M, Tricart P (1984) Pérénité de la sédimentation pélagique du Jurassique supérieur jusque dans le Crétacé supérieur au-dessus de la croûte océanique Téthysienne Ligure: La série supra-ophiolitique du lac des Cordes (zone Piémontaise des Alpes occidentales au sud-est de Briancon). CR Acad Sci Paris II 299:1069–1072

    Google Scholar 

  • Frey M, Hunziker JC, O'Neil JR, Schwander HW (1976) Equilibrium-desequilibrium relations in the Monte-Rosa granite, western Alps: petrological, Rb-Sr and stable isotope data. Contrib Mineral Petrol 55:147–179

    Google Scholar 

  • Gebauer D, Grünenfelder M (1979) U-Pb zircon and Rb-Sr mineral dating of eclogites and their country rocks. Example: Münchberg gneiss massif, Northeast Bavaria. Earth Planet Sci Lett 42:35–44

    Google Scholar 

  • Gebauer D, Bernard-Griffiths J, Grünenfelder M (1981) U-Pb zircon and monazite dating of a mafic-ultramafic complex and its country rocks. Example: Sauviat-sur-Vige, French Central Massif. Contrib Mineral Petrol 76:292–300

    Google Scholar 

  • Gebauer D, Lappin MA, Grünenfelder M, Wittenbach A (1985) The age and origin of some Norwegian eclogites: a U-Pb and REE study. Chem Geol (Isot Geos Sect) 52:227–247

    Google Scholar 

  • Gebauer D (1989) Isotopic systems — geochronology of eclogites. In: DA Carswell (ed) Eclogite-facies rocks. Blacki and Son, Glasgow, in press

    Google Scholar 

  • Goldstein SL, O'Nions RK, Hamilton PJ (1984) A Sm-Nd isotopic study of atmospheric dusts and particulates from major river systems. Earth Planet Sci Lett 70:221–236

    Google Scholar 

  • Hawkesworth CJ (1976) Rb/Sr geochronology in the Eastern Alps. Contrib Mineral Petrol 54:225–244

    Google Scholar 

  • Heinrich CA (1982) Kyanite-eclogite to amphibolite facies evolution of hydrous mafic and pelitic rocks, Adula nappe, Central Alps. Contrib Mineral Petrol 81:30–38

    Google Scholar 

  • Hoppe G (1966) Zirkone aus Granuliten. Ber Dtsch Ges Geol Wiss Reihe B 11:47–81

    Google Scholar 

  • Hunziker JC (1970) Polymetamorphism in the Monte-Rosa, Western Alps. Eclogae Geol Helv 63/1:151–161

    Google Scholar 

  • Hunziker JC (1974) Rb-Sr and K-Ar age determination and the Alpine tectonic history of the Western Alps. Mem Ist Geol Mineral Univ Padova 31:1–55

    Google Scholar 

  • Hunziker JC, Zingg A (1980) Lower Paleozoic amphibolite to granulite facies metamorphism in the Ivrea zone. Schweiz Mineral Petrogr Mitt 60:181–213

    Google Scholar 

  • Hurford AJ, Hunziker JC (1985) Alpine cooling history in the Monte Mucrone eclogites (sesia-Lanzo zone): fission-track evidence: Schweiz Mineral Petrogr Mitt 65:325–334

    Google Scholar 

  • Hy C (1984) Métamorphisme polyphasé et évolution tectonique dans la croûte continentale éclogitisée: les séries granitiques et pélitiques du Mont Mucrone (zone Sésia-Lanzo, Alpes Italiennes). Thèse, Université de Paris VI, pp 224

  • Jaffrey AH, Flynn KF, Glendenin LE, Bentle EC, Essling AM (1971) Precision measurement of half lives and specific activities of 235U and 238U. Phys Rev C4:1889–1906

    Google Scholar 

  • Jahn BM, Bernard-Griffiths J, Charlot R, Cornichet J, Vidal P (1980) Nd and Sr isotopic compositions and R.E.E. abundances of Cretaceous MORB (hole 417 D and 418A, legs 51, 52 and 53). Earth Planet Sci Lett 48:171–184

    Google Scholar 

  • Köppel V (1974) Isotopic U-Pb age of monazites and zircons from the crust-mantle transition and adjacent units of the Ivrea and Ceneri zones (Southern Alps, Italy). Contrib Mineral Petrol 43:55–70

    Google Scholar 

  • Krogh TE (1973) A low contamination method for decomposition of zircon and the extraction of U and Pb for isotopic age determinations. Geochim Cosmochim Acta 37:485–494

    Google Scholar 

  • Liew TC, Hoffmann AW (1988) Precambrian crustal components, plutonic associations, plate environment of the Hercynian fold belt of central Europe: indications from a Nd and Sr isotopic study. Contrib Mineral Petrol 98:129–138

    Google Scholar 

  • Marthaler M, Fudral D, Deville E, Rampnoux JP (1986) Mise en évidence du Crétacé supérieur dans la couverture septentrionale de Dora Maira, région de Suse, Italie (Alpes occidentales). Conséquences paléogéographiques et structurales. CR Acad Sci Paris II 302:91–96

    Google Scholar 

  • Michard A (1965) Une nappe de socle dans les Alpes cottiennes internes? Implications paléogéographiques et rôle éventuel des mouvements Crétacés. CR Acad Sci Paris 260:4012–4015

    Google Scholar 

  • Monié P (1984) Etude par la méthode 39Ar/40Ar de la redistribution de l'argon dans les minéraux des socles anciens repris par l'orogenèse Alpine. Application à la géochronologie des Massifs de L'Argentera-Mercantour, du Mont-Rose et de la Grande Kabylie. Thèse, Université de Montpellier, pp 206

  • Nakamura N (1974) Determination of REE, Ba, Fe, Mg, Na and K in carbonaceous and ordinary chondrites. Geochim Cosmochim Acta 38:757–775

    Google Scholar 

  • Oberhänsli R, Hunziker JC, Martinotti G, Stern WB (1985) Geochemistry, geochronology and petrology of Monte Mucrone: an example of eo-alpine eclogitization of Permian granitoids in the Sesia-Lanzo zone, Western Alps, Italy. Chem. Geol (Isot Geos Sect) 52:165–184

    Google Scholar 

  • Paquette JL, Peucat JJ, Bernard-Griffiths J, Marchand J (1985) Evidence for Precambrian relics shown by U-Pb zircon dating of eclogites and associated rocks in the Hercynian belt of South Brittany, France. Chem Geol (Isot Geos Sect) 52:203–216

    Google Scholar 

  • Paquette JL, Balé P, Ballèvre M, Georget Y (1987) Géochronologie et géochimie des éclogites du Léon: nouvelles contraintes sur l'évolution géodynamique du NW du Massif Armoricain. Bull Mineral 110:683–696

    Google Scholar 

  • Peucat JJ, Vidal P, Godard G, Postaire B (1982) Precambrian U-Pb zircon ages in eclogites and garnet-pyroxenites from South Brittany (France): an old oceanic crust in the West European Hercynian belt? Earth Planet Sci Lett 60:70–78

    Google Scholar 

  • Peucat JJ, Jégouzo P, Vidal P, Bernard-Griffiths J (1988) Continental crust formation seen through the Sr and Nd isotope systematics of S-type granites in the Hercynian belt of Western Europe. Earth Planet Sci Lett 88:60–68

    Google Scholar 

  • Pin C (1986) Datation U-Pb sur zircons à 285 Ma du complexe gabbro-dioritique du Val Sésia-Val Mastallone et âge tardiHercynien du métamorphisme granulitique de la zone IvreaVerbano (Italie). CR Acad Sci Paris 303 II 9:827–830

    Google Scholar 

  • Pin C, Lancelot JR (1982) U-Pb dating of an early Paleozoic bimodal magmatism in the French Massif Central and of its further metamorphic evolution. Contrib Mineral Petrol 79:1–12

    Google Scholar 

  • Pognante U (1989) Lawsonite, blueschist and eclogite formation in the southern Sesia zone, western Alps, Italy. Eur J Mineral 1 (in press)

  • Pupin JP (1976) Signification des caractères morphologiques du zircon commun des roches en pétrologie. Base de la méthode typologique. Applications. Thèse d'état, Nice, pp 394

  • Stacey JS, Kramers JD (1975) Approximation of terrestrial lead isotope evolution by a two stage model. Earth Planet Sci Lett 26:207–221

    Google Scholar 

  • Steiger RH, DePaolo DJ (1986) Genealogy of the basement of the central Alps. Terra Cognita 6 (abstr):127

    Google Scholar 

  • Stille P, Buletti M (1987) Nd-Sr isotopic characteristics of the Lugano volcanic rocks and constraints on the continental crust formation in the South Alpine domain (N Italy-Switzerland). Contrib Mineral Petrol 96:140–150

    Google Scholar 

  • Stöckhert B, Jäger E, Voll G (1986) K-Ar age determinations on phengites from the internal part of the Sesia zone, western Alps, Italy. Contrib Mineral Petrol 92:456–470

    Google Scholar 

  • Taylor SR, Mac Lennan SM (1985) The continental crust: its composition and evolution. Blackwell, Oxford pp 312

    Google Scholar 

  • Tilton GR, Schreyer W, Schertl HP (1989) Pb-Sr-Nd isotopic behaviour of deeply subducted crustal rocks from the Dora Maira massif, western Alps, Italy. Geochim Cosmochim Acta (in press)

  • Vialon P (1966) Etude géologique du massif cristallin Dora Maira, Alpes cottiennes internes, Italie. Thèse d'état, Université de Grenoble, mém 4, travaux du laboratoire de géologie de la Faculté des Sciences de Grenoble

  • Vocke RD, Hanson GN, Grünenfelder M (1987) Rare earth element mobility in the Roffna gneiss, Switzerland. Contrib Mineral Petrol 95:145–154

    Google Scholar 

  • York D (1966) Least-square fitting of a straight line. Can J Phys 44:1079–1086

    Google Scholar 

Download references

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  1. Jean-Louis Paquette

    Present address: Laboratory for Isotope Geochemistry and Mass Spectrometry, Swiss Federal Institute of Technology, E.T.H. Zentrum, CH-8092, Zürich, Switzerland

Authors and Affiliations

  1. Laboratoiré de Géochimie isotopique, C.A.E.S.S., Avenue du Général Leclerc, Campus de Beaulieu, F-35042, Rennes Cedex, France

    Jean-Louis Paquette & Jean-Jacques Peucat

  2. Département de Géologie, Ecole normale supérieure, 24 rue Lhomond, F-75005, Paris, France

    Christian Chopin

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Paquette, JL., Chopin, C. & Peucat, JJ. U-Pb zircon, Rb-Sr and Sm-Nd geochronology of high- to very-high-pressure meta-acidic rocks from the western Alps. Contr. Mineral. and Petrol. 101, 280–289 (1989). https://doi.org/10.1007/BF00375313

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