Abstract
Lead isotope data on whole rocks, feldspars and sulfides from the Ivrea zone indicate that the magmas which formed the Hercynian (?) mafic complex derived from an isotopically anomalous mantle with a lead isotope composition that resembled average continental crustal leads. Contamination during magma emplacement played a minor role and probably accounts for second order variations of the μ values. Similar leads were observed in Caledonian orthogneisses, late-Hercynian granites and volcanics of the near-by Ceneri zone. Metasediments of the kinzigitic series of the Ivrea zone as well as metasediments of the Ceneri zone contain lead with high μ values which indicates of prolonged crustal history in agreement with the mean ages of 1900 to 2500 my of their detrital zircon populations. Amphibolites of the kinzigitic series still contain MORB-type leads, and contamination by metasediments played only a minor role in spite of the regional metamorphism in upper amphibolite facies. The trace leads of stratiform sulfide ores are variable mixtures of mantle-derived and crustal leads depending on the host rock lithologies which are either amphibolites, amphibolites plus metasediments or metasediments.
Similar content being viewed by others
References
Ben Othman D, Polvé M, Allègre CJ (1984) Nd-Sr isotopic composition of granulites and constraints on the evolution of the lower continental crust. Nature 307:510–515
Bigioggero B, Brigo L, Ferrario A, Gregnanin A, Montrasio A, Zuffardi P (1979) Strona Valley (Fe-Ni-Cu and Fe-Ba) ore deposits: excursion book. Mem Sci Geol 33:33–39
Boriani A, Sacchi R (1974) The “Insubric” and other tectonic lines in the Southern Alps (NW Italy). Mem Soc Geol Ital 13:1–11
Boriani A, Colombo A, Giobbi EO, Pagliani GP (1974) The “Appinite suite” of Massiccio dei Laghi (Northern Italy) and its relationship to the regional metamorphism. Rend Soc Ital Mineral Petrol 30:983–917
Boriani A, Giobbi EO, del Moro A (1981) Composition, level of intrusion, and age of the “serie dei laghi” orthogneisses (northern Italy — Ticino, Switzerland). Rend Soc Ital Mineral Petrol 38:191–205
Buletti M (1983) Zur Geochemie und Entstehungsgeschichte der Granat-Amphibolit des Gambarognogebietes, Ticino, Südalpen. Schweiz Mineral Petrol Mitt 63:233–248
Cumming GL, Richards JR (1975) Ore lead isotope ratios in a continuously changing Earth. Earth Planet Sci Lett 28:155–171
Ferrario A, Garuti G, Sighinolfi GP (1982) Platinum and palladium in the Ivrea-Verbano basic complex, Western Alps, Italy. Econ Geol 77:1548–1555
Ferrario A, Garuti G, Rossi A, Sighinolfi GP (1983) Petrographic and metallogenetic outlines of the “La Balma — Monte Capio” ultramafic — mafic body (Ivrea-Verbano Basic Complex, NW Italian Alps). In: Schneider H-J (ed) Mineral deposits of the Alps and of the Alpine Epoch in Europe. Springer, Berlin Heidelberg New York, pp 28–40
Garuti G, Rinaldi R (1985) Mineralogy of melonite group PGM and other tellurides from the Ivrea-Verbano basic complex, western Italian Alps. Can Mineral 23:303
Garuti G, Rivalenti G, Rossi A, Siena F, Sinigoi S (1980) The Ivrea-Verbano nafic to ultramafic complex of the Italian western Alps: discussion of some petrologic problems and a summary. Red Soc Ital Mineral Petrol 36:717–749
Garuti G, Gorgoni C, Sighinolfi PG (1984) Sulfide mineralogy and chalcophile and siderophile element abundances in the Ivrea-Verbano mantle peridotites (Western Italian Alps). Earth Planet Sci Lett 70:69–87
Garuti G, Fiandri P, Rossi A (1986) Sulfide composition and phase relations in the Fe-Ni-Cu ore deposits of the Ivrea-Verbano basic complex (Western Alps, Italy). Miner Deposita 21:22–34
German Research Group of Explosion Seismology (1968) Topographie des Ivrea-Körpers abgeleitet aus seismischen und gravimetrischen Daten. Schweiz Mineral Petrol Mitt 48:235–246
Graeser S (1969) Isotopic composition of lead in some basic and ultrabasic rocks from the Alps. Earth Planet Sci Lett 6:491–497
Graeser S, Hunziker JC (1968) Rb-Sr and Pb-Isotopen-Bestimmungen an Gesteinen und Mineralien der Ivrea-Zone. Schweiz Mineral Petrol Mitt 48:189–204
Graeter P (1951) Geologie und Petrographie des Malcantone (südliches Tessin). Schweiz Mineral Petrol Mitt 31:3612–483
Grünenfelder M, Tilton GR, Bell K, Blenkinsop J (1986) Lead and Strontium isotope relationships in the Oka carbonatite complex, Quebec. Geochim Cosmochim Acta 50:461–475
Hamelin B, Dupre B, Allegre CJ (1984) The lead isotope systematics of ophiolite complexes. Earth Planet Sci Lett 67:351–366
Hart SR (1984) A large scale isotope anomaly in the Southern Hemisphere mantle. Nature 309:753–757
Hart WK (1984) Chemical and isotopic evidence for mixing between depleted and enriched mantle, northwestern USA. Geochim Cosmochim Acta 49:131–144
Heilmann H, Lensch G (1978) Some results about sulfur isotope distribution in the Ivrea zone. Mem Ist Geol Mineral Univ Padova 33:197–204
Hofmann AW, White WM (1982) Mantle plumes from ancient oceanic crust. Earth Planet Sci Lett 57:421–436
Hunziker JC, Zingg A (1980) Lower Palaeozoic amphibolite to granulite facies metamorphism in the Ivrea zone (Southern Alps, N. Italy). Schweiz Mineral Petrol Mitt 60:181–213
Hunziker JC, Zingg A (1982) Zur Genese der ultrabasischen Gesteine der Ivrea-Zone. Schweiz Mineral Petrol Mitt 62:483–486
Jaquemin H, Sheppard SMF, Vidal P (1982) Isotope geochemistry (O, Sr, Pb) of the Golda Zuelva and Mbouto anorogenic complexes, North Cameroun: mantle origin with evidence of crustal contamination. Earth Planet Sci Lett 61:97–111
Köppel V (1974) Isotopic U-Pb ages of monazites and zircons from the crustmantle transition and adjacent units of the Ivrea and Ceneri zones (Southern Alps, Italy). Contrib Mineral Petrol 43:55–70
Köppel V, Grünenfelder M (1971) A study of inherited and newly formed zircons from paragneisses and granitized sediments of the Strona-Ceneri zone (Southern Alps). Schweiz Mineral Petrol Mitt 51:385–409
Köppel V, Grünenfelder M (1978) Monazite and zircon U-Pb ages from the Ivrea and Ceneri zones. Mem Ist Geol Mineral Univ Padova 33:257
Kramers J (1977) Pb and Sr isotopes in cretaceous kimberlites and mantle derived xenoliths from southern Africa. Earth Planet Sci Lett 34:419–431
Kruhl JH, Voll G (1978) Excursion-guide to the western part of the Finero peridotite-metagabbro-complex of the Ivrea zone (N. Italy). Mem Ist Geol Mineral Univ Padova 33:17–26
Lancelot J, Allègre JC (1974) Origin of carbonatitic magma in the light of the Pb-U-Th isotope system. Earth Planet Sci Lett 22:233–238
Omenetto P, Brigo L (1974) Metallogenesi nel quadro dell'orogene ercinici delle Alpi. Mem Soc Geol Ital 13:339–362
Peretti A, Köppel V (1986) Geochemical and lead isotope evidence for a midocean ridge type mineralization within a polymetamorphic ophiolite complex (Monte del Forno, N-Italy — Switzerland). Earth Planet Sci Lett 80:252–264
Pin C (1986) Datation U-Pb sur zircons a 285 Ma du complexe gabbro-dioritique du V. Sesia — V. Mastallone et age tardihercynien du metamorphism granulitique de la zone Ivrea-Verbano (Italie). C R Acad Sci Paris 303/II/9:827–830
Pin C, Sills JD (1986) Petrogenesis of layered gabbros and ultramafics rocks from Val Sesia, the Ivrea zone, NW Italy: trace element and isotope geochemistry. In: Dawson JB (ed) The nature of the lower crust. Geol Soc Spec Publ 25:231–249
Polve M (1983) Les isotopes du Nd et du Sr dans les lherzolites orogeniques: Contribution à la determination de la structure et de la dynamique du manteau superieur. These, Université de Paris
Richards JR, Fletcher IR, Blockley JG (1981) Pilbara galenas: precise isotopic assey of the oldest Australian leads; model ages and growth-curve implications. Miner Deposita 16:7–30
Rivalenti G, Garuti G, Rossi A, Siena F, Sinigoi S (1981) Existence of different peridotite types and of a layered igneous complex in the Ivrea zone of the western Alps. J Petrol 22:127–153
Rivalenti G, Rossi A, Siena F, Sinigoi S (1984) The layered series of the Ivrea-Verbano igneous somplex, Western Alps, Italy. Tschermaks Mineral Petrol Mitt 33:77–99
Schmid R (1967) Zur Petrographie und Struktur der Zone Ivrea-Verbano zwischen Valle d'Ossola und Val Grande (Prov. Novara, Italien). Schweiz Mineral Petrol Mitt 47:935–1117
Shervais JW (1979) Thermal emplacement model for the Alpine lherzolite massif at Balmuccia, Italy. J Petrol 20:795–820
Sills JD, Tarney J (1984) Petrogenesis and tectonic significance of amphibolites interlayered with metasedimentary gneisses in the Ivrea zone, Southern Alps, NW Italy. Tectonophysics 107:187–206
Sills JD, Pin C, Greenwood PB (1986) Petrogenesis of meta-gabbros from Val Sesia, Ivrea zone, NW Italy: trace element and isotope evidence. Terra Cognita 6/2:184
Smith CB (1983) Pb, Sr, and Nd isotopic evidence for sources of southern African Cretaceous kimberlites. Nature 304:51–54
Stacey JS, Kramers JD (1975) Approximation of terrestrial lead isotope evolution by a two stage model. Earth Planet Sci Lett 26:207–221
Stille P, Unruh DM, Tatsumoto M (1983) Pb, Sr, Nd and Hf isotopic evidence of multiple sources for Oahu, Hawaii basalts. Nature 304 No. 5921:25–29
Süssli C (1985) Contributo alla conoscenza chimico-petrografica dele vulcaniti permiane del distretto eruttivo del Varesotto. Diplomarbeit, ETH-Zurich
Tilton GR (1979) Isotopic studies of Cenozoic Andean calc-alkaline rocks. Carnegie Inst Washington Yearb 78:298–304
Tilton GR, Barreiro BA (1980) Origin of Pb in Andean calc-alkaline lavas, southern Peru. Science 210:1245–1247
Wright JW, Shervais JW (1980) Emplacement age of the Balmuccia lherzolite massif, NW Italy. 26th Int Geol Congr Paris 2:804
Zartmann RE, Doe BR (1981) Plumbotectonics- the Model. Tectonophysics 75:135–162
Zingg A (1983) The Ivrea and Strona-Ceneri zones (Southern Alps, Ticino and N-Italy) — a review. Schweiz Mineral Petrol Mitt 63:361–392
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cumming, G.L., Köppel, V. & Ferrario, A. A lead isotope study of the northeastern Ivrea zone and the adjoining Ceneri zone (N-Italy): evidence for a contaminated subcontinental mantle. Contr. Mineral. and Petrol. 97, 19–30 (1987). https://doi.org/10.1007/BF00375211
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00375211