Abstract
Ion microprobe U-Th-Pb analyses of residual cores and metamorphic mantles of zircons from three high grade paragneisses from the Seve Nappe Complex, north-western Sweden, show that: 1) The sediments comprising the protolith of the Seve Nappes gneisses over a distance of 250 km were probably derived from similarly-aged source terranes. 2) Those source terranes were dominated by rocks with ages in the range 1400 to 1730 Ma, with minor components at least as young as 1000 Ma. The oldest component identified is 1730±12 Ma old. 3) Those rocks had U and Th contents normal for felsic igneous rocks. 4) The gneiss protolith was metamorphosed to granulite grade during the Caledonian. There is evidence to suggest that the peak of metamorphism may not have been synchronous throughout the Nappes. 5) The metamorphism probably included a reduction of about a factor of ten in the gneisses' Th/U.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Black LP, Williams IS, Compston W (1986) Four zircon ages from one rock: the history of a 3930 Ma-old granulite from Mount Sones, Enderby Land, Antarctica. Contrib Mineral Petrol 94:427–437
Claesson S (1982) Caledonian metamorphism of Proterozoic Seve rocks on Mt. Åreskutan, southern Swedish Caledonides. Geol Foeren Stockholm Foerh 103:291–304
Claesson S (1987) Isotopic evidence for the Precambrian provenance and Caledonian metamorphism of high grade paragneisses from the Seve Nappes, Scandinavian Caledonides. I. Conventional U-Pb data on zircons and Sm-Nd whole rock data. Contrib Mineral Petrol 97:196–204
Compston W, Williams IS, Meyer C (1984) U-Pb geochronology of zircons from lunar breccia 73217 using a sensitive high mass-resolution ion microprobe. J Geophys Res 89:B525-B534
Cumming GL, Richards JR (1975) Ore lead isotope ratios in a continuously changing earth. Earth Planet Sci Lett 28:155–171
Dewey JF (1969) Evolution of the Appalachian/Caledonian orogen. Nature 222:124–129
Falkum T, Petersen JS (1980) The Sveconorwegian orogenic belt, a case of late-Proterozoic plate-collision. Geol Rundsch 69:622–647
Gebauer D, Lappin MA, Grünenfelder M, Wyttenbach A (1985) The age and origin of some Norwegian eclogites: a U-Pb zircon and REE study. Chem Geol 52:227–247
Gee DG (1975) A tectonic model for the central parts of the Scandinavian Caledonides. Am J Sci 275A:468–515
Gorbatschev R (1980) The Precambrian development of southern Sweden. Geol Foeren Stockholm Foerh 102:129–136
Gray CM (1977) The geochemistry of central Australian granulites in relation to the chemical and isotopic effects of granulite facies metamorphism. Contrib Mineral Petrol 65:79–89
Griffin WL, Brueckner HK (1980) Caledonian Sm-Nd ages and a crustal origin for Norwegian eclogites. Nature 285:319–321
Heier KS, Compston W (1969) Interpretation of Rb-Sr age patterns in high-grade metamorphic rocks, north Norway. Nors Geol Tidsskr 49:257–283
Jacobsen SB, Heier KS (1978) Rb-Sr isotope systematics in metamorphic rocks, Kongsberg sector, south Norway. Lithos 11:257–276
Jacobsen SB, Wasserburg GJ (1978) Interpretation of Nd, Sr and Pb isotope data from Archaean migmatites in Lofoten-Vesterålen, Norway. Earth Planet Sci Lett 41:245–253
Kalsbeek F (1981) The northward extent of the Archaean basement of Greenland — A review of Rb-Sr whole rock ages. Precambrian Res 14:203–219
Lambert IB, Heier KS (1967) The vertical distribution of uranium, thorium and potassium in the continental crust. Geochim Cosmochim Acta 31:377–390
Le Pichon X, Sibuet JC, Francheteau J (1977) The fit of the continents around the North Atlantic Ocean. Tectonophysics 38:169–209
Lundqvist T (1979) The Precambrian of Sweden. Sver Geol Unders Ser C768:1–87
Patchett PJ, Bylund G, Upton BGJ (1978) Palaeomagnetism and the Grenville Orogeny: new Rb-Sr ages from dolerites in Canada and Greenland. Earth Planet Sci Lett 40:349–364
Peucat JJ, Tisserant D, Caby R, Clauer N (1985) Resistance of zircons to U-Pb resetting in a prograde metamorphic sequence of Caledonian age in East Greenland. Can J Earth Sci 22:330–338
Priem HNA, Verschure RH (1982) Review of the isotope geochronology of the high-grade Precambrian of SW Norway. Geol Rundsch 71:81–84
Saxena SK (1966) Evolution of zircons in sedimentary and metamorphic rocks. Sedimentology 6:1–33
Silver LT, Williams IS, Woodhead JA (1980) Uranium in granites from the southwestern United States: actinide parent-daughter systems, sites and mobilization. Report of the Department of Energy DOE-GJBX-45(81), California Institute of Technology, pp 379
Stearn JEF, Piper JDA (1984) Palaeomagnetism of the Sveconorwegian Mobile Belt of the Fennoscandian Shield. Precambrian Res 23:201–246
Steiger RH, Jäger E (1977) Subcommission on geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet Sci Lett 36:359–362
Weaver BL, Tarney J (1981) Lewisian gneiss geochemistry and Archaean crustal development models. Earth Planet Sci Lett 55:171–180
Welin E, Gorbatschev R, Kähr AM (1982) Zircon dating of polymetamorphic rocks in southwestern Sweden. Sver Geol Unders Ser C797:1–34
Wilson MR, Hamilton PJ, Fallick AE, Aftalion M, Michard A (1985) Granites and early Proterozoic crustal evolution in Sweden: evidence from Sm-Nd, U-Pb and O systematics. Earth Planet Sci Lett 72:376–388
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Williams, I.S., Claesson, S. Isotopic evidence for the Precambrian provenance and Caledonian metamorphism of high grade paragneisses from the Seve Nappes, Scandinavian Caledonides. Contr. Mineral. and Petrol. 97, 205–217 (1987). https://doi.org/10.1007/BF00371240
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00371240