Advertisement

Contributions to Mineralogy and Petrology

, Volume 98, Issue 1, pp 13–23 | Cite as

U/Pb ages of ophiolites and arc-related plutons of the Norwegian Caledonides: implications for the development of Iapetus

  • G. R. Dunning
  • R. B. Pedersen
Article

Abstract

U/Pb zircon ages are reported for four ophiolites and three crosscutting arc-related plutons from the Norwegian Caledonides. Plagiogranite differentiated from gabbro of the Karmøy ophiolite is dated at 493+7/-4 Ma whereas arc-related trondhjemite cutting this ophiolite crystallized at 485+/−2 Ma. A crosscutting clinopyroxene-phyric gabbro intrusion is dated at 470+9/−5 Ma by near concordant magmatic titanite (sphene) and discordant U-rich (2903–6677 ppm) zircon. Lower intercepts of 247+/−68 and 191+/−70 Ma defined by the plagiogranite and clinopyroxene-phyric gabbro best-fit lines may reflect a real low-T alteration/rift-related event.

A plagiogranite differentiate of the Gullfjellet ophiolite complex is dated at 489+/−3 Ma and a crosscutting arc-related tonalite is 482+6/−4 Ma. Both of these ages overlap with those of the correlative rocks at Karmøy suggesting that they are parts of one ophiolitic terrane with a common history.

Trondhjemite associated with the Leka ophiolite is dated at 497+/−2 Ma, indicating that supra-subduction zone magmatism there may be coeval with spreading which formed the Karmøy axis sequence.

The U/Pb zircon ages of Norwegian ophiolites reported here, combined with ages of other Appalachian-Caledonian ophiolite complexes in Britain and Canada, indicate a narrow age range for the generation of at least two marginal basins in the Tremadoc-Arenig. Two spreading episodes documented at Karmøy are separated in time by intrusion of arc-related trondhjemite magmas at 485+/−2 Ma and may correlate with two separate spreading events documented in other ophiolites.

The Solund/Stavfjorden ophiolite, at 443+/−3 Ma, is the only late Ordovician ophiolite yet documented in the entire Appalachian-Caledonian Orogen and it probably represents a small, short-lived marginal basin late in the history of the Iapetus Ocean. It is correlative with Caradocian ensialic marginal basin magmatism in Wales and the Trondheim region, and with tholeiitic gabbro-diorite plutons that intruded Newfoundland ophiolites in a tensional regime after emplacement of the ophiolites over the continental margin.

Keywords

Zircon Ordovician Continental Margin Titanite Marginal Basin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Austrheim A, Griffin Wl (1985) Shear deformation and eclogite formation within granulite-facies anorthosites of the Bergen Arcs, western Norway. In: Smith DC, Franz G, Gebauer D (eds) Chemistry and petrology of Ecklogites. Chem Geol Spec Iss 50:267–281Google Scholar
  2. Birkeland T (1981) The geology of Jaeren and adjacent districts. A contribution to the Caledonian nappe tectonics of Rogaland, southwest Norway. Norsk Geol Tidsskr 61:213–235Google Scholar
  3. Bluck BJ, Halliday AN, Aftalion M, Macintyre RM (1980) Age and origin of Ballantrae ophiolite and its significance to the Caledonian orogeny and Ordovician time scale. Geology 8:492–495Google Scholar
  4. Brekke H, Solberg PO (in press) The geology of Atløy. Nor Geol TidsskrGoogle Scholar
  5. Brekke H, Furnes H, Nordås J, Hertogen J (1984) Lower Palaeozoic convergent plate margin volcanism on Bømlo, SW Norway, and its bearing on the tectonic environments of the Norwegian Caledonides. J Geol Soc London 141:1015–1032Google Scholar
  6. Claesson S, Klingspor I, Stephens MB (1983) U-Pb and Rb-Sr isotopic data on an Ordovician volcanic-subvolcanic complex from the Tjopasi Group, Køli Nappes, Swedish Caledonides. Geol Foeren Stockholm Foerh 105:9–15Google Scholar
  7. Dallmeyer RD (1977) Diachronous ophiolite obduction in western Newfoundland: evidence from 40Ar/39Ar ages of the Hare Bay metamorphic aureole. Am J Sci 277:61–72Google Scholar
  8. Dallmeyer RD, Gee DG (1986) 40Ar/39Ar mineral dates from retrogressed eclogites within the Baltoscandian miogeocline: implications for a polyphase Caledonian orogenic evolution. Geol Soc Am Bull 97:26–34Google Scholar
  9. Davis DW (1982) Optimum linear regression and error estimation applied to U-Pb data. Can J Earth Sci 19:2141–2149Google Scholar
  10. Dunning GR (1987) U/Pb geochronology of the Coney Head Complex, Newfoundland. Can J Earth Sci 24:1072–1075Google Scholar
  11. Dunning GR, Chorlton LB (1985) The Annieopsquotch ophiolite belt of southwest Newfoundland: geology and tectonic significance. Geol Soc Am Bull 96:1466–1476Google Scholar
  12. Dunning GR, Krogh TE (1985) Geochronology of ophiolites of the Newfoundland Appalachians. Can J Earth Sci 22:1659–1670Google Scholar
  13. Dunning GR, Krogh TE, Kean BF, O'Brien S, Swinden HS (1986a) U/Pb zircon ages of volcanic groups from the central mobile belt, Newfoundland. Geol Assoc Can, Ann Meet 11:66Google Scholar
  14. Dunning GR, Krogh TE, Pedersen RB (1986b) U/Pb zircon ages of Appalachian-Caledonian ophiolites. Terra Cognita 6:155Google Scholar
  15. Dunning GR, Kean BF, Thurlow JG, Swinden HS (1987) Geochronology of the Buchans, Roberts Arm and Victoria Lake Groups and Mansfield Cove Complex, Newfoundland. Can J Earth Sci 24:1175–1184Google Scholar
  16. Faerseth RB, MacIntyre RM, Naterstad J (1976) Mesozoic alkaline dykes in the Sunnhordaland region, western Norway: ages, geochemistry and regional significance. Lithos 9:331–345Google Scholar
  17. Furnes H (1974) Structural and metamorphic history of the Lower Palaeozoic metavolcanics and associated sediments in the Solund area, Sogn. Nor Geol Unders 302:33–74Google Scholar
  18. Furnes H, Skjerlie FJ, Tysseland M (1976) Plate tectonic model based on greenstone geochemistry in the Late Precambrian-Lower Paleozoic sequence in the Solund-Stavfjorden areas, west Norway. Nor Geol Tidsskr 56:161–186Google Scholar
  19. Furnes H, Roberts D, Sturt BA, Thon A, Gale GH (1980) Ophiolite fragments in the Scandinavian Caledonides. Ophiolites. Proc Int Ophiolite Symp Cyprus, pp 582–600Google Scholar
  20. Furnes H, Mitchell JG, Robins B, Ryan P, Skjerlie FJ (1982) Petrography and geochemistry of peralkaline, ultrapotassic syenite dykes of Middle Permian age, Sunnfjord, west Norway, Nor Geol Tidsskr 62:147–159Google Scholar
  21. Furnes H, Austrheim H, Amaliksen KG, Nordås J (1983) Evidence for an incipient early Caledonian (Cambrian) orogenic phase in southwestern Norway. Geol Mag 120:607–612Google Scholar
  22. Furnes H, Thon A, Nordås J, Garmann LB (1983) Trace element geochemistry of metabasalts from some Norwegian ophiolite fragments: evidence of mineralogical and chemical mantle heterogeneity. Contrib Mineral Petrol 79:295–307Google Scholar
  23. Furnes H, Ryan PD, Grenne T, Roberts D, Sturt BA, Prestvik T (1985) Geological and geochemical classification of the ophiolitic fragments in the Scandinavian Caledonides. In: Gee DG, Sturt BA (eds) The Caledonian Orogen — Scandinavia and related areas. Wiley, New York, pp 657–670Google Scholar
  24. Gebauer D, Lappin MA, Grunenfelder M, Koestler A, Wyttenbach A (1982) Age and origin of some Norwegian eclogites: a U-Pb zircon and REE study. Terra Cognita 2:233Google Scholar
  25. Gebauer D, Lappin MA, Grunenfelder M, Wyttenbach A (1985) The age and origin of some Norwegian eclogites: a U-Pb zircon and REE study. Chem Geol 52:227–247Google Scholar
  26. Gee DG, Zachrisson E (1979) The Caledonides in Sweden. Sver Geol Unders C769:1–33Google Scholar
  27. Grenne T, Roberts D (1980) Geochemistry and volcanic setting of the Ordovician Forbordfjell and Jonsvatn greenstones, Trondheim region, central Norwegian Caledonides. Contrib Mineral Petrol 74:374–386Google Scholar
  28. Griffin WL (1972) Formation of eclogites and the coronas in an orthosites, Bergen Arcs, Norway. Geol Soc Am Mem 135:37–63Google Scholar
  29. Griffin WL, Brueckner HK (1980) Caledonian Sm-Nd ages and a crustal origin for Norwegian eclogites. Nature 285:319–321Google Scholar
  30. Griffin WL, Brueckner HK (1985) REE, Rb-Sr and Sm-Nd studies of Norwegian eclogites. Chem Geol 52:249–271Google Scholar
  31. Gustavson M, Prestvik T (1979) The igneous complex of Hortavaer, Nord-Trondelag, Central Norway. Nor Geol Unders 348:73–92Google Scholar
  32. Heier KS, Naterstad J, Bryhni I (1972) A Rb-Sr whole-rock isochron date from the Stavanger area, south Norway. Nor Geol Tidsskr 52:377–383Google Scholar
  33. Henningsmoen G (1952) Early Middle Cambrian fauna from Rogaland, SW Norway. Nor Geol Tidsskr 30:13–21Google Scholar
  34. Ingdahl SE (1985) Stratigraphy, structural geology and metamorphism in the Os area, Major Bergen Arc. Cand Real thesis, University of Bergen, NorwayGoogle Scholar
  35. Karig DE, Sarewitz DR, Haeck GD (1986) Role of strike-slip faulting in the evolution of allochthonous terranes in the Philippines. Geology 14:852–855Google Scholar
  36. Kokelaar BP, Howells MF, Bevins RE, Roach RA, Dunkley PN (1984) The Ordovician marginal basin of Wales. In: Kokelaar BP, Howells MF (eds) Marginal basin geology: volcanic and associated sedimentary and tectonic processes in modern and ancient marginal basins. Geol Soc London Spec Publ 16:245–269Google Scholar
  37. Krogh TE (1973) A low contamination method for hydrothermal decomposition of zircon and extraction of U an Pb for isotopic age determinations. Geochim Cosmochim Acta 37:485–494Google Scholar
  38. Krogh TE (1982) Improved accuracy of U-Pb zircon ages by the creation of more concordant systems using an air abrasion technique. Geochim Cosmochim Acta 46:637–649Google Scholar
  39. Krogh TE, Davis GL (1975) The production and preparation of 205Pb for use as a tracer for isotope dilution analyses. Carnegie Inst Washington Year 74:416–417Google Scholar
  40. Krogh TE, Mysen BO, Davis GL (1974) A Paleozoic age for the primary minerals of a Norwegian eclogite. Ann Rep Geophys Lab 73:575–576Google Scholar
  41. Kvale A (1960) The nappe area in the Caledonides on western Norway, Excursion Guide. Nor Geol Unders 212e:43Google Scholar
  42. Leat PT, Thorpe RS (1986) Ordovician volcanism in the Welsh Borderland. Geol Mag 123:629–640Google Scholar
  43. Leat PT, Jackson SE, Thorpe RS, Stillman CJ (1986) Geochemistry of bimodal basalt-subalkaline/alkaline rhyolite provinces within the southern British Caledonides. J. Geol Soc London 143:259–273Google Scholar
  44. Løvlie R, Mitchell JG (1982) Complete remagnetization of some Permian dykes from western Norway induced during burial/uplift. Phys Earth Planet Inter 30:415–421Google Scholar
  45. Ludwig KR (1980) Calculation of uncertainties of U-Pb isotope data. Earth Planet Sci Lett 46:212–220Google Scholar
  46. Mørk MBE, Mearns EW (1986) Sm-Nd isotopic systematics of a gabbro-eclogite transition. Lithos 19:255–267Google Scholar
  47. Nordås J, Amaliksen KG, Brekke H, Suthren R, Furnes H, Sturt BA, Robins B (1985) Lithostratigraphy and petrochemistry of Caledonian rocks on Bømlo, SW. Norway. In: Sturt BA, Gee D (eds) The Caledonide Orogen — Scandinavia and related areas. Wiley, New York, pp 679–692Google Scholar
  48. Pedersen RB (1982) The Karmøy ophiolite plutonic suite. Cand Real thesis, University of Bergen, NorwayGoogle Scholar
  49. Pedersen RB, Malpas J (1985) The origin of oceanic plagiogranites from the Karmøy ophiolite, Western Norway. Contrib Mineral Petrol 88:36–52Google Scholar
  50. Prestvik T (1980) The Caledonian ophiolite complex of Leka, north central Norway. In: Proc Int Ophiolite Symp Cyprus pp 555–566Google Scholar
  51. Priem HNA, Boelrijk NAIM, Hebeda EH, Verdurmen EAT, Verschure RH (1975) Isotopic dating of the Caledonian Bindal and Svenningdal granitic massifs, central Norway. Nor Geol Unders 319:29–36Google Scholar
  52. Pringle IR, Kvale A, Anonsen LB (1975) The age of the Hernes granite, Lower Bergsdalen Nappe, western Norway. Nor Geol Tidsskr 55:191–195Google Scholar
  53. Riis F, Ramberg IB (1981) The Uppermost Allochthon, the Rodingfjaellet and the Helgeland Nappe Complexes in a segment south of Ranafjorden, Norway. Terra Cognita 1:69Google Scholar
  54. Roberts D, Grenne T, Ryan PD (1984) Ordovician marginal basin development in the central Norwegian Caledonides. In: Kokelaar BP, Howells MF (eds) Marginal basin geology. Geol Soc London Spec Publ 16:233–244Google Scholar
  55. Ryan PD, Skevington D, Williams DM (1980) A revised interpretation of the Ordovician stratigraphy of Sor Trondelag and its implications for the evolution of the Scandinavian Caledonides. Proc IGCP Cal Orogen Symp Virginia Poly Inst Mem 2:99–103Google Scholar
  56. Searle MP, Malpas J (1980) Structure and metamorphism of rocks beneath the Semail ophiolite of Oman and their significance in ophiolite obduction. Trans R Soc Edinburgh Earth Sci 71:247–262Google Scholar
  57. Sigmond EM (1978) Description of the geological map sheet Sauda. Nor Geol Unders 343:73–85Google Scholar
  58. Sigmond EM, Andresen A (1976) A Rb-Sr isochron age of metaandesites from Skorpehei, Suldal, south Norway. Nor Geol Tidsskr 56:315–319Google Scholar
  59. Skjerlie FJ, Pringle IR (1978) A Rb/Sr whole-rock isochron date from the lowermost gneiss complex of the Gaula area, west Norway and its regional implications. Nor Geol Tidsskr 58:259–265Google Scholar
  60. Solli T (1981) The geology of the Torvastad Group, the cap rocks to the Karmøy ophiolite. Cand Real thesis, University of Bergen, NorwayGoogle Scholar
  61. Stacey JS, Kramers JD (1975) Approximation of terrestrial lead isotope evolution by a two-stage model. Earth Planet Sci Lett 26:207–221Google Scholar
  62. Stephens MB, Gustavson M, Ramberg IB, Zachrisson E (1985) The Caledonides of Central-north Scandinavia — a tectonostratigraphic overview. In: Gee DG, Sturt BA (eds) The Caledonide Orogen — Scandinavia and related areas. Wiley, New York, pp 135–162Google Scholar
  63. Størmer L (1940) Dictyonema shales outside the Oslo region. Nor Geol Tidsskr 20:161–175Google Scholar
  64. Stukas V, Reynolds PH (1974) 40Ar/39Ar dating of the Long Range dykes, Newfoundland. Earth Planet Sci Lett 22:256–266Google Scholar
  65. Sturt BA, Roberts D, Furnes H (1984) A conspectus of Scandinavian Caledonian Ophiolites. In: Gass IG, Lippard SJ, Shelton AW (eds) Ophiolites and oceanic lithosphere. Geol Soc London Spec Publ 13:381–391Google Scholar
  66. Sturt BA, Thon A (1978) Caledonides of southern Norway. Geol Surv Canada Pap 78-13, 39–47Google Scholar
  67. Sturt BA, Thon A, Furnes H (1979) The Karmøy ophiolite, southwest Norway. Geology 7:316–320Google Scholar
  68. Sturt BA, Thon A, Furnes H (1980) The geology and preliminary geochemistry of the Karmøy ophiolite, S.W. Norway. Proc Int Ophiolite Symp Cyprus pp 538–554Google Scholar
  69. Thon A (1980) Steep shear zones in the basement and associated deformation in the cover sequence on Karmøy. SW Norwegian Caledonides. J Structural Geol 2:78–80Google Scholar
  70. Thon A (1985) The Gullfjellet ophiolite complex and the structural evolution of the Major Bergen Arc, west Norwegian Caledonides. In: Sturt BA, Gee D (eds) The Caledonide Orogen — Scandinavia and related areas. Wiley, New York, pp 671–677Google Scholar
  71. Trettin HP, Loveridge WD, Sullivan RW (1982) U-Pb ages on zircon from the M'Clintock West massif and the Markham Fiord pluton, northernmost Ellesmere Island Geological Survey of Canada Paper 82-1c, pp 161–166Google Scholar
  72. Tucker RD, Raheim A, Krogh TE, Corfu F (1987) Uranium-lead zircon and titanite ages from the northern portion of the Western Gneiss Region, south central Norway. Earth Planet Sci Lett 81:203–211Google Scholar
  73. van Eysinga FWB (1975) Geological time table, 3rd edn. Elsevier Publishing Company 1978Google Scholar
  74. Whalen JB, Currie KL, van Breeman O (1987) Episodic Ordovician-Silurian plutonism in the Topsails Igneous Terrane, western Newfoundland. Trans R Soc Edinburgh Earth Sci 78:17–28Google Scholar
  75. Williams H, Dallmeyer RD, Wanless RK (1976) Geochronology of the Twillingate Granite and Herring Neck Group, Notre Dame Bay, Newfoundland. Can J Earth Sci 13:1591–1601Google Scholar

Copyright information

© Springer-Verlag 1988

Authors and Affiliations

  • G. R. Dunning
    • 1
  • R. B. Pedersen
    • 2
  1. 1.Department of GeologyRoyal Ontario MuseumTorontoCanada
  2. 2.Geologisk Institutt Avd. AUniversitetet I BergenBergenNorway

Personalised recommendations