Abstract
An approximately 7 km thick, continuous sequence of granulite-facies rocks from the lower crust, which contains a lower granulite-pyriclasite unit and an upper metapelite unit, occurs in the NW Serre of the Calabrian massif. The lower crustal section is overlain by a succession of plutonic rocks consisting of blastomylonitic quartz diorite, tonalite, and granite, and is underlain by phyllonitic schists and gneisses.
Discordant apparent zircon ages, obtained from granulites and aluminous paragneisses, indicate a minimum age of about 1,900 m.y. for the oldest zircon populations. The lower intersection point of the discordia with the concordia at 296±2 m.y. is also marked by concordant monazites. Therefore, the age of 296±2 m.y. is interpreted as the minimum age of granulite-facies metamorphism.
Concordant zircon ages were obtained from a metamorphic quartz monzogabbronorite sill (298±5 m.y.) and an unmetamorphosed tonalite (295±2 m.y.); they are interpreted as the intrusion ages.
Discordant zircon ages from a blastomylonitic quartz diorite gneiss, situated between the lower crustal unit and the non-metamorphosed tonalite, reveal recent or geologically young lead loss by diffusion. The 207Pb/206Pb ages of the two analysed size-fractions point to an intrusion age similar to that of the overlying tonalite.
Rb-Sr mineral ages are younger in the granulite-pyriclasite unit than in the overlying metapelite unit. Feldspars from the granulite-pyriclasite unit yield ages of about 145 m.y. and those from the metapelite unit 176±5 m.y. In the same way, the biotite cooling ages range between 108 and 114 m.y. in the granulitepyriclasite and between 132 and 135 m.y. in the metapelite unit and the tonalite. Some still younger biotite ages are explained by the influence of tectonic shearing on the Rb-Sr systems. A muscovite from a postmetamorphic aplite in the metapelite unit yields a cooling age of 203±4 m.y.
The Rb-Sr isotopic analyses from migmatite bands do not lie on an isochron, perhaps due to limited isotopic exchange between the small scale layers during the long cooling period after the peak of metamorphism.
In the phyllonitic gneisses and schists a Hercynian metamorphism is indicated by a muscovite age of 268±4 m.y., whereas the biotite age of 43±1 m.y. from the same sample can be correlated with an Alpine greenschist-facies metamorphism.
On the basis of the radiometric dates and of the P-T path of the lower crustal section deduced petrologically, the following model is presented: the end of the Hercynian granulite-facies metamorphism was accompanied by an uplift of the lower crustal rocks into intermediate crustal levels and by synchronous plutonic intrusions into the lower crust and higher crustal levels, but essentially into the latter. Substantial further uplift did not occur until after cooling from the temperature of the granulite-facies metamorphism to the biotite closing temperature. This cooling lasted for about 185 m.y. in the lower part and for about 160 m.y. in the upper part of the lower crust section.
A comparison between the geologic evolutions of the NW Serre of Calabria and the Ivrea Zone of the Alps demonstrates striking similarities. The activity of deep seated faults in both areas at least since late Hercynian time raises the possibility that a fault precursor of the boundary of the Adriatic microplate already existed at this time.
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References
Alvarez, W.: A former continuation of the Alps. Geol. Soc. Am. Bull. 87, 891–896 (1976)
Amodio-Morelli, L., Bonardi, G., Colonna, V., Dietrich, D., Giunta, G., Ippolito, F., Liguori, V., Lorenzoni, S., Paglionico, A., Perrone, V., Piccarreta. G., Russo, M., Scandone, P., Zanettin-Lorenzoni, E., Zupetta, A.: L'arco Calabro-Peloritano nel-l'orogeneApenninico-Maghrebide. Mem. Soc. Geol. It. (in press)
Arnold, A., Scharbert, H.G.: Rb-Sr Altersbestimmungen an Granuliten der südlichen Böhmischen Masse in Österreich. Schweiz. Mineral. Petrogr. Mitt. 53, 61–78 (1973)
Behr, HJ.: Subfluenz-Prozesse im Grundgebirgs-Stockwerk Mitteleuropas. Z. dt. geol. Ges. 129, 283–318 (1978)
Bernoulli, D.: North Atlantic and Mediterranean Mesozoic facies: a comparison. In: Initial reports of the Deep Sea Drilling Project Vol. 11, pp. 801–871. Washington: US Government Print ing Office 1972 (quoted from Hunziker, 1974)
Borsi, S., Dubois, R.: Données géochronologiques sur l'histoire hercynienne et alpine de la Calabre Centrale. C.R. Acad. Sci. [D] (Paris), 266, 72–75 (1968)
Borsi S., Hieke-Merlin, O., Lorenzoni, S., Paglionico, A., Zanet-tin-Lorenzoni, E.: Stilo unit and “dioritic-kinzigitic” unit in le Serre (Calabria, Italy). Geological, petrological, geochronological characters. Boll. Soc. Geol. It. 95, 219–245 (1976)
Cameron, A.E., Smith, D.H., Walker, R.L.: Mass spectrometry of nanogram-size samples of lead. Anal. Chem. 41, 525–526 (1969)
Ergenzinger, P., Görler, K., Ibbeken, H., Obenauf, P., Rumohr, J.: Calabrian arc and Ionian sea: vertical movements, erosional and sedimentary balance. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, and K. Schmidt, eds.), pp. 359–373. Stuttgart: Schweizerbart 1978
Ferrara, G., Longinelli, A.: Età di due rocce granitiche della zona delle Serre in Calabria. Boll. Geol. Soc. It. 80, 25–36 (1961)
German research group for explosion seismology: Topographie des ‘Ivrea-Körpers’ abgeleitet aus seismischen und gravimetrischen Daten. Schweiz. Mineral. Petrogr. Mitt. 48, 235–246 (1968)
Giese, P., Görler, H.: Zur Stellung Kalabriens im geodynamischen Bauplan Italiens. Nachr. dt. geol. Ges. 9, 67–77 (1974)
Giese, P., Reutter, K.-J.: Crustal and structural features of the margins of the Adria microplate. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder and K. Schmidt, eds.), pp. 565–588. Stuttgart: Schweizerbart 1978
Görler, K.: Critical review of postulated nappe structures in Southern Calabria. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, and K. Schmidt, eds.), pp. 349–354. Stuttgart: Schweizerbart 1978
Görler, K., Giese, P.: Aspects of the evolution of the Calabrian arc. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, and K. Schmidt, eds.), pp. 374–388. Stuttgart: Schweizerbart 1978
Graeser, S., Hunziker, J.C.: Rb-Sr and Pb Isotopen Bestimmungen an Gesteinen und Mineralien der Ivrea Zone. Schweiz. Mineral. Petrogr. Mitt. 48, 189–204 (1968)
Grauert, B.: U-Pb systematics in heterogeneous zircon populations from the Precambrian basement of the Maryland Piedmont. Earth Planet. Sci. Lett. 23, 238–248 (1974)
Grauert, B., Arnold, A.: Deutung diskordanter Zirkonalter der Silvretta und des Gotthardmassivs (Schweizer Alpen). Contrib. Mineral. Petrol. 20, 34–56 (1968)
Grauert, B., Hänny, R., Soptrajanova, G.: Geochronology of a polymetamorphic and anatectic gneiss region: the Moldanubicum of the area Lam-Deggendorf, Eastern Bavaria, Germany. Contrib. Mineral. Petrol. 45, 37–63 (1974)
Grauert, B., Wagner, M.E.: Age of the granulite-facies metamorphism of the Wilmington complex, Delaware-Pennsylvania Piedmont. Am. J. Sci. 275, 683–691 (1975)
Green, D.H., Ringwood, A.E.: An experimental investigation of the gabbro to eclogite transformation and its petrological applications. Geochim. Cosmochim. Acta 31, 767–833 (1967)
Haccard, D., Lorenz, C., Grandjacquet, C.: Essai sur l'évolution tectonogenétique de la liaison Alpes-Apennides (de la Ligurie à la Calabre). Mem. Soc. Geol. It. 11, 309–341 (1972)
Herzberg, C.T.: Clinopyroxene compositions in spinel-lherzolites. In: Progress in experimental petrology Vol. 3 (G.M. Biggar, ed.), pp. 241–242. London: NERS, Ser. D, No. 6, 1975
Holdaway, M.J.: Stability of andalusite and the aluminium silicate phase diagram. Am. J. Sci. 271, 97–131 (1971)
Holdaway, M.J., Lee, S.M.: Fe-Mg Cordierite stability in highgrade pelitic rocks based on experimental, theoretical, and natural observations. Contrib. Mineral. Petrol. 63, 175–198 (1977)
Hunziker, J.C.: Rb-Sr and K-Ar age determination and the alpine tectonic history of the Western Alps. Mem. Ist. Geol. Min. Univ. Padova 31, 1–55 (1974)
Jäger, E., Niggli, E., Wenk, E.: Rb-Sr Altersbestimmungen an Glimmern der Zentralalpen. Beitr. Geol. Karte Schweiz N.F. 134, 76 S. (1967)
Jäger, E., Watznauer, A.: Einige Rb-Sr Datierungen an Granuliten des sächsischen Granulitgebirges. Mber. dtsch. Akad. Wiss. 11, 420–426 (1969)
Kerrick, D.M.: Experimental determination of muscovite+quartz stability with \(P_{{\text{H}}_{\text{2}} {\text{O}}} < P_{{\text{total}}} \). Am. J. Sci. 272, 946–958 (1972)
Köppel, V.: Isotopic U-Pb ages 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 (1974)
Köppel, V., Grünenfelder, M.: Concordant U-Pb ages of monazites from the central Alps and the timing of the high temperature Alpine metamorphism, a preliminary report. Schweiz. Mineral. Petrogr. Mitt. 55, 129–132 (1975)
Krogh, T.E.: A low-contamination method for hydrothermal decomposition of zircon and extraction of U and Pb for isotopic age determination. Geochim. Cosmochim. Acta 37, 485–494 (1973)
Obata, M.: The solubility of Al2O3 in orthopyroxene in spinel and plagioclase peridotites and spinel pyroxenites. Am. Mineral. 61, 804–816 (1976)
Pidgeon, R.T., Aftalion, M.: The geochronological significance of discordant U-Pb ages of oval-shaped zircons from a Lewisian gneiss from Harris, Outer Hebrides. Earth Planet. Sci. Lett. 17, 269–274 (1972)
Quitzow, H.W.: Der Deckenbau des kalabrischen Massivs und seiner Randgebiete. Abhand. Gesell. der Wissensch. zu Göttingen, III. Folge 13, 63–179 (1935)
Richardson, S.W., Gilbert, M.C., Bell, P.M.: Experimental determination of kyanite-andalusite and andalusite-sillimanite equilibria: the aluminium silicate triple point. Am. J. Sci. 267, 259–272 (1969)
Schenk, V.: Metamorphe Entwicklung des Altkristallins in der NW-Serre, kalabrisches Massiv, Süd-Italien. Nachr. dt. geol. Ges. 17, 28–29 (1977)
Schenk, V.: Granulitfazielle Metamorphose in der nordwestlichen Serre, kalabrisches Massiv (Süd-Italien): Geologie und Petrologie. Diss., Ruhr-Universität Bochum, 262 S. (1978)
Schenk, V., Schreyer, W.: Granulite-facies metamorphism in the Northern Serre, Calabria, Southern Italy. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, and K. Schmidt, eds.), pp. 341–346. Stuttgart: Schweizerbart 1978
Schmid, R.: Zur Petrographie und Struktur der Zone Ivrea-Verbano zwischen Valle d'Ossola und Val Grande (Prov. Novara, Italien). Schweiz. Mineral. Petrogr. Mitt. 47, 935–1118 (1967)
Schütte, K.-G.: Crustal structure of Southern Italy. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, and K. Schmidt, eds.), pp. 315–320. Stuttgart: Schweizerbart 1978
Schwarz, G.: Magnetic measurements in Northern Calabria. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, and K. Schmidt, eds.). pp. 321–323. Stuttgart: Schweizerbart 1978
Steiger, R.H., Jäger, E.: Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36, 359–362 (1977)
Wagner, G.A., Reimer, G.M., Jäger, E.: Cooling ages derived by apatite fission-track, mica Rb-Sr and K-Ar dating. The uplift and cooling history of the central Alps. Mem. Ist. Geol. Min. Univ. Padova 30, 27 pp. (1977)
Wetherhill, G.W.: Discordant Uranium-Lead ages. Trans. Am. Geophys. Union 37, 320–326 (1956)
York, D.: Least-squares fitting of a straight line with correlation errors. Earth Planet. Sci. Lett. 5, 320–324 (1969)
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Schenk, V. U-Pb and Rb-Sr radiometric dates and their correlation with metamorphic events in the granulite-facies basement of the serre, Southern Calabria (Italy). Contr. Mineral. and Petrol. 73, 23–38 (1980). https://doi.org/10.1007/BF00376258
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DOI: https://doi.org/10.1007/BF00376258