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Isotope studies of granitoids from the Bangenhuk Formation, Ny Friesland Caledonides, Svalbard

Published online by Cambridge University Press:  01 May 2009

Å. Johansson ,
D. G. Gee ,
L. Björklund  and
P. Witt-Nilsson
Å. Johansson
Affiliation:
Laboratory for Isotope Geology, Swedish Museum of Natural History, Box 50 007, S-104 05 Stockholm, Sweden
D. G. Gee
Affiliation:
Department of Geophysics, Uppsala University, Box 556, S-751 22, Uppsala, Sweden
L. Björklund
Affiliation:
Department of Geology, University of Göteborg, S-412 96 Göteborg, Sweden
P. Witt-Nilsson
Affiliation:
Department of Geology, University of Lund, Sölvegatan 13, S-223 62 Lund, Sweden
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Abstract

The Caledonian Hecla Hoek succession in Ny Friesland, eastern Svalbard has been interpreted, for many decades, to be a continuous stratigraphic sequence. Early Palaeozoic and Neoproterozoic strata in its upper parts pass more or less conformably down into amphibolite facies rocks (Stubendorffbreen Supergroup) at depth. Recent isotopic age-determination and structural studies have indicated that the Stubendorffbreen succession is tectonostratigraphic and made up of at least three major thrust sheets. This paper provides new data from two meta-igneous units within the succession, the Bangenhuk and Instrumentberget gneisses. Both are granitoid sheets, consisting mainly of red, strongly lineated gneisses of monzogranitic composition; the Bangenhuk unit also contains some lenses of little deformed granitoids, as well as cross-cutting aplite dykes, amphibolitized dolerites and subordinate metasedimentary rocks. The latter are locally cut by granitoids. U—Pb zircon dating of six samples of variably deformed Bangenhuk granitoids, including one cross-cutting aplitic dyke, has yielded ages between 1720 and 1770 Ma, the higher values generally from the less deformed samples. The Instrumentberget gneissic granite yielded an age of 1737+46−41 Ma. These ages are interpreted to date the time of intrusion of the granitoids at around 1750 Ma; the younger ages may have been slightly lowered by Caledonian deformation, particularly those from specimens located close to a major fracture (the Billefjorden Fault Zone) in Wijdefjorden—Austfjorden. U—Pb dating of titanite from the least deformed granitoid also yields comparable Palaeoproterozoic ages; in the more deformed rocks, however, titanites give evidence of Caledonian ductile deformation at c. 410 Ma. The Rb—Sr system of the corresponding whole rock samples has been disturbed and yields an errorchron age of about 1650 Ma and, for some samples, an impossibly low initial Sr ratio. The Sm—Nd system may be more intact and yields initial εNd values of −2 to −3, suggesting some contribution from older crustal material to the granitoid magmas. The results indicate the presence of extensive units of Palaeoproterozoic granitic basement within the Lower Hecla Hoek succession of Ny Friesland, supporting the hypothesis that the latter is composed of tectonically intercalated basement and cover units.

Type
Articles
Information
Geological Magazine , Volume 132 , Issue 3 , May 1995 , pp. 303 - 320
Copyright
Copyright © Cambridge University Press 1995

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References

Balashov, Yu. A., Larionov, A. N., Gannibal, L. F., Sirotkin, A. N., Tebenkov, A. M., Ryungenen, G. I., & Ohta, Y., 1993. An Early Proterozoic U—Pb zircon age from an Eskolabreen Formation gneiss in southern Ny Friesland, Spitsbergen. Polar Research 12, 147–52.Google Scholar
Bayly, M. B., 1957. The Lower Hecla Hoek of Ny Friesland, Spitsbergen. Geological Magazine 94, 377–92.CrossRefGoogle Scholar
Blomstrand, C. W., 1864. Geognostiska iaktagelser under en resa till Spetsbergen år 1861 (Geognostical observations during a voyage to Spitsbergen in the year 1861). Kungliga Svenska Vetenskapsakademiens Handlingar 4 (6), 1–46.Google Scholar
Carlsson, P., Johansson, Å., & Gee, D. G., In press. Geochemistry of the Paleoproterozoic Bangenhuk granitoids, Ny Friesland, Svalbard. Geologiska Föreningens i Stockholm Fürhandlingar.Google Scholar
Debon, F., & Le Fort, P., 1982. A chemical—mineralogical classification of common plutonic rocks and associations. Transactions of the Royal Society of Edinburgh: Earth Sciences 73, 135–49.CrossRefGoogle Scholar
de Geer, G., 1909. Some leading lines of dislocation in Spitzbergen. Geologiska Föreningens i Stockholm Förhandlingar 31, 199–208.CrossRefGoogle Scholar
De Paolo, D. J., 1981. Neodymium isotopes in the Colorado Front Range and crust—mantle evolution in the Proterozoic. Nature 291, 193–6.Google Scholar
Fairbairn, P. E., 1933. The petrology of the Hecla Hook Formation in central Spitsbergen. Geological Magazine 70, 437–54.Google Scholar
Gayer, R. A., 1969. The geology of the Femilsjøen region of northwestern Ny Friesland, Spitsbergen. Norsk Polarinstitutt Skrifter 145, 1–45.Google Scholar
Gayer, R. A., & Wallis, R. H., 1966. The petrology of the Harkerbreen Group of the Lower Hecla Hoek of Ny Friesland and Olav V Land, Spitsbergen. Norsk Polarinstitutt Skrifter 140, 1–32.Google Scholar
Gee, D. G., 1986. Svalbard’s Caledonian terranes reviewed. Geologiska Föreningens i Stockholm Förhandlingar 108, 284–6.CrossRefGoogle Scholar
Gee, D. G., 1994. Svalbard’s Caledonian Terranes. In Swedish Research in Svalbard — A Cruise Report (eds Karlqvist, A. and Carlsson, M. Lönnroth), pp. 92–117. Stockholm: Swedish Polar Research Secretariat.Google Scholar
Gee, D. G., Björklund, L., & Stølen, L.-K., 1994. Early Proterozoic basement in Ny Friesland — implications for the Caledonian tectonics of Svalbard. Tectonophysics 231, 171–82.CrossRefGoogle Scholar
Gee, D. G., & Page, L., 1994. Caledonian terrane assembly on Svalbard: new evidence from Ar/Ar dating in Ny Friesland. American Journal of Science 294, 1166–86.CrossRefGoogle Scholar
Gee, D. G., Schouenborg, B., Peucat, J. J., Abakumov, S. A., Krasil’scikov, A. A., & Tebenkov, A. M., 1992. New evidence of basement in the Svalbard Caledonides: early Proterozoic zircon ages from Ny Friesland granites. Norsk Geologisk Tidsskrift 72, 181–90.Google Scholar
Harland, W. B., 1941. Geological notes on the Stubendorff Mountains, West Spitsbergen. Proceedings of the Royal Society of Edinburgh B51 (10), 119–29.Google Scholar
Harland, W. B., 1959. The Caledonian sequence in Ny Friesland, Spitsbergen. Quarterly Journal of the Geological Society of London 114, 307–43.Google Scholar
Harland, W. B., 1985. Caledonide Svalbard. In The Caledonide Orogen — Scandinavia and Related Areas (eds Gee, D. G. and Sturt, B. A.), pp. 999–1016. Chichester: Wiley.Google Scholar
Harland, W. B., Scott, R. A., Auckland, K. A., & Snape, I., 1992. The Ny Friesland orogen, Spitsbergen. Geological Magazine 129, 679–708.CrossRefGoogle Scholar
Harland, W. B., Wallis, R. H., & Gayer, R. A., 1966. A revision of the lower Hecla Hoek succession in central north Spitsbergen and correlation elsewhere. Geological Magazine 103, 70–97.Google Scholar
Jacobsen, S. B., & Wasserburg, G. J., 1984. Sm—Nd isotopic evolution of chondrites and achondrites. II. Earth and Planetary Science Letters 67, 137–50.CrossRefGoogle Scholar
Kober, B., 1986. Whole-grain evaporation for 207Pb/206Pb age investigations on single zircons using a doublefilament thermal ion source. Contributions to Mineralogy and Petrology 93, 482–90.CrossRefGoogle Scholar
Krasil’scikov, A. A., 1973. Stratigraphy and palaeotectonics of the Precambrian and early Palaeozoic of Spitsbergen. Trudy Arkticheskogo Nauchno- Issledovatel’skogo Instituta 172, 1–120 (in Russian).Google Scholar
Krasil’scikov, A. A., 1979. Stratigraphy and tectonics of the Precambrian of Svalbard. Norsk Polarinstitutt Skrifter 167, 73–9.Google Scholar
Krogh, T. E., 1973. A low-contamination method for hydrothermal decomposition of zircon and extraction of U—Pb for isotopic age determination. Geochimica Cosmochimica Ada 37, 485–94.Google Scholar
Larionov, A. N., Johansson, Å., Tebenkov, A. M., & Sirotkin, A. N. In press. U-Pb zircon ages from the Eskolabreen Formation, southern Ny Friesland, Svalbard. Norsk Geologisk Tidsskrift.Google Scholar
Ludwig, K. R., 1991 a. PBDAT — A computer program for processing Pb—U—Th isotope data, version 1.20. U.S. Geological Survey Open-file Report 88–542.Google Scholar
Ludwig, K. R., 1991 b. ISOPLOT — A plotting and regression program for radiogenic-isotope data, version 2.56. U.S. Geological Survey Open-file Report 91–445.Google Scholar
Manby, G. M., 1990. The petrology of the Harkerbreen Group, Ny Friesland, Svalbard: protoliths and tectonic significance. Geological Magazine 127, 129–46.Google Scholar
Manby, G. M., & Lyberis, N., 1991. Contrasting tectonometamorphic terranes in the NE Svalbard: Sm/Nd—Rb/Sr isotopic and structural constraints. Terra Nova Abstracts Supplement 4, 22–3.Google Scholar
McCulloch, M. T., & Chappell, B. W., 1982. Nd isotopic characteristics of S- and I-type granites. Earth and Planetary Science Letters 58, 51–64.Google Scholar
Nathorst, A. G., 1910. Beiträge zur Geologie der Bären Insel, Spitzbergens und des König-Karls-Landes. Bulletin of the Geological Institution of the University of Uppsala 10, 261–415.Google Scholar
Nordenskiöld, A. E., 1863. Geografisk och geognostisk beskrifning över de nordöstra delarna af Spetsbergen och Hinlopen Strait. Kungliga Svenska Vetenskapsakademiens Handlingar 4 (7), 1–25.Google Scholar
Nordenskiöld, A. E., 1866. Utkast till Spetsbergens geologi. Kungliga Svenska Vetenskapsakademiens Handlingar 6 (7), 1–35.Google Scholar
Parrish, R. R., 1987. An improved micro-capsule for zircon dissolution in U—Pb geochronology. Chemical Geology (Isotope Geoscience Section) 66, 99–102.Google Scholar
Sokolov, V. N., Krasil’scikov, A. A., & Livshits, Y. Y., 1968. The main features of the tectonic structure of Spitsbergen. Geological Magazine 105, 95–115.CrossRefGoogle Scholar
Stacey, J. S., & Kramers, J. D., 1975. Approximation of terrestrial lead isotope evolution by a two-stage model. Earth and Planetary Science Letters 26, 207–21.Google Scholar
Steiger, R. H., & Jäger, E., 1977. Convention on the use of decay constants in geo- and cosmochronology. Earth and Planetary Science Letters 36, 359–62.Google Scholar
Streckeisen, A., 1976. To each plutonic rock its proper name. Earth Science Reviews 12, 1–33.Google Scholar
Wallis, R. H., 1969. The Planetfjella Group of the Lower Hecla Hoek of Ny Friesland, Spitsbergen. Norsk Polarinstitutt Årbok 1967, 80–108.Google Scholar
Welin, E., 1992. Isotopic results of the Proterozoic crustal evolution of south-central Sweden: review and conclusions. Geologiska Föreningens i Stockholm Förhandlingar 114, 299–312.Google Scholar
Welin, E., Kähr, A.-M., & Lundegårdh, P. H., 1980. Rb—Sr isotope systematics at amphibolite facies conditions, Uppsala region, Eastern Sweden. Precambrian Research 13, 87–101.Google Scholar
Welin, E., Vaasjoki, M., & Suominen, V., 1983. Age differences between Rb—Sr whole rock and U—Pb zircon ages of syn- and postorogenic Svecokarelian granitoids in Sottunga, SW Finland. Lithos 16, 297–305.Google Scholar
York, D., 1969. Least squares fitting of a straight line with correlated errors. Earth and Planetary Science Letters 5, 320–4.Google Scholar