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Basement–cover relationships in the East Greenland Caledonides: evidence from the Eleonore Bay Supergroup at Ardencaple Fjord

Published online by Cambridge University Press:  03 November 2011

N. J. Soper
Affiliation:
Department of Earth Sciences, The University, Leeds LS2 9JT, UK
A. K. Higgins
Affiliation:
Grønlands Geologiske Undersøgelse, Østervoldgade 10, DK-1350, København K, Denmark

Abstract

The Eleonore Bay Supergroup (EBG) is a 16 km-thick shallow-water sequence of Neoproterozoic age that is preserved within the East Greenland Caledonides in several tracts, surrounded by crystalline gneisses and schistose supracrustal rocks. The apparent downward transition from non-metamorphic EBG into gneiss gave rise to the classic ‘stockwerke’ hypothesis, in which all the metamorphism was regarded as Caledonian, and differences in grade were ascribed to the ascent of a migmatite front to different levels within the orogen. Field and isotopic studies in the 1970s however revealed that the underlying gneisses and schists had undergone orogenic reworking in mid-Proterozoic time; the EBG–basement contact was then interpreted as an approximately bedding-parallel décollement with apparent lag geometry, that is with EBG cover rocks in its hangingwall.

Recent work in the northernmost EBG tract, at Ardencaple Fjord, has shed light on the problems posed by the basal relationships of the EBG, and together with regional structural and stratigraphic data leads to the following interpretation. There are two regionally important basement-cover interfaces within the East Greenland Caledonides. The earlier one is between Archaean/early Proterozoic gneisses and early Proterozoic supracrustal rocks, which were pervasively deformed in mid-Proterozoic time and form the basement to the Neoproterozoic Eleonore Bay cover sequence. This was deposited on a vast, continually subsiding shelf that is now preserved in East and NE Greenland and Svalbard, and contains Grenville detritus. EBG deposition was terminated by major extensional faulting of Vendian age; the succeeding Tillite Group is interpreted as a syn-rift sequence, presumably associated with the opening of Iapetus.

The EBG–basement contacts that are not late faults are inferred to be extensional shear zones of Vendian age. These were reactivated in compression during the Caledonian orogeny in the Silurian, with metamorphic and fabric convergence, which accounts for the apparent downward transition from sedimentary rocks through schists into gneisses. Caledonian shortening was not large; inversion of the Vendian grabens was incomplete, so that the marginal shear zones retained their lag geometry and large tracts of low grade Eleonore Bay sediments are preserved at the present erosion level, surrounded by Proterozoic basement rocks, within the Caledonian belt of East Greenland.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1993

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References

Bengaard, H.-J. 1989. Geometrical and geological analysis of photogrammetrically measured deformed sediments of the fjord zone, central East Greenland. GRØNLANDS GEOL UNDERS RAPP, Open File Series 89/6, 101 pp.Google Scholar
Bond, G. C., Nickeson, P. A. & Kominz, M. A. 1984. Breakup of a supercontinent between 625 Ma and 555 Ma: new evidence and implications for continental histories. EARTH PLANET SCI LETT 70, 325–45.CrossRefGoogle Scholar
Eha, S. 1953. The pre-Devonian sediments of Ymer Ø, Suess Land and Ella Ø (East Greenland) and their tectonics. MEDDELELSER OM GRØNLAND 111(2), 105 pp.Google Scholar
Fränkl, E. 1953a. Geologische Untersuchungen in Ost-Andrées Land (NE-Grönland). MEDDELELSER OM GRØNLAND 113(4), 160 pp.Google Scholar
Fränkl, E. 1953b. Die geologische Karte von Nord-Scoresby Land (NE Grönland). MEDDELELSER OM GRØNLAND 113(5), 56 pp.Google Scholar
Haller, J. 1953. Geologie und Petrographie von West-Andrées Land und Ost-Frænkels Land (NE-GRøNLAND). MEDDELELSER OM GRØNLAND 113(5), 196 pp.Google Scholar
Haller, J. 1955. Der ‘Zentrale Metamorphe Komplex’ von NE-Grönland. Teil I, Die Geologische Kart von Suess Land, Gletscher Land und Goodenoughs Land. MEDDELELSER OM GRØNLAND 73(1), 3, 174 pp.Google Scholar
Haller, J. 1970. Tectonic map of East Greenland (1:500,000). An account of tectonism, plutonism and volcanistn in East Greenland. MEDDELELSER OM GRØNLAND 171(5), 286 pp.Google Scholar
Haller, J. 1971. Geology of the East Greenland Caledonides. New York: Interscience Publishers.Google Scholar
Hambrey, M. J. 1989. The Late Proterozoic sedimentary evolution of East Greenland: its place in understanding the evolution of the Caledonide orogen. In Gayer, R. A. (Ed.) The Caledonide geology of Scandinavia, 257–62. London: Graham & Trotman.CrossRefGoogle Scholar
Hambrey, M. J. & Spencer, A. M. 1987. Late Precambrian glaciation of East Greenland. MEDDELELSER OM GRØNLAND GEOSCI 19, 50 pp.CrossRefGoogle Scholar
Harland, W. B., Scott, R. A., Auckland, K. A. & Snape, I. 1992. The Ny Friesland Orogen, Spitzbergen. GEOL MAG 129, 679708.CrossRefGoogle Scholar
Henriksen, N. 1985. The Caledonides of central East Greenland 70°-76°N. In Gee, D. G. & Sturt, B. A. (Eds) The Caledonide Orogen, Scandinavia and related areas, 1095–113. London: Wiley.Google Scholar
Henriksen, N. & Higgins, A. K. 1976. East Greenland Caledonian fold belt. In Escher, A. & Watt, W. S. (Eds) Geology of Greenland, 182246. Copenhagen: The Geological Survey of Greenland.Google Scholar
Henriksen, N., Friderichsen, J. D., Strachan, R. A., Soper, N. J. & Higgins, A. K. 1989. The Caledonian and pre-Caledonian geology of the region between Grandjean Fjord and Bessel Fjord (75°-76°N), North-East Greenland. GRØNLANDS GEOL UNDERS RAPP 145, 90–7.Google Scholar
Herrington, P. M. & Fairchild, I. J. 1989. Carbonate shelf and slope facies evolution prior to Vendian glaciation, central East Greenland. In Gayer, R. A. (Ed.) The Caledonide geology of Scandinavia, 263–73. London: Graham & Trotman.CrossRefGoogle Scholar
Higgins, A. K. 1976. Pre-Caledonian metamorphic complexes within the southern part of the East Greenland Caledonides. J GEOL SOC LONDON 132, 289305.CrossRefGoogle Scholar
Higgins, A. K. 1988. The Krummedal supracrustal sequence in East Greenland. In Winchester, J. A. (Ed.) Later Proterozoic stratigraphy of the North Atlantic Regions, 8696. London: Blackie.CrossRefGoogle Scholar
Higgins, A. K. & Phillips, W. E. A. 1979. East Greenland Caledonides—an extension of the British Caledonides. In Harris, A. L., Holland, C. H. & Leake, B. E. (Eds) The Caledonides of the British Isles—Reviewed. GEOL SOC LONDON SPEC PUBL 8, 1931.Google Scholar
Higgins, A. K., Friderichsen, J. D. & Thyrsted, T. 1981. Precambrian metamorphic complexes in the East Greenland Caledonides (72°-74°N)—their relationships to the Eleonore Bay Group, and Caledonian orogenesis. GRØNLANDS GEOL UNDERS RAPP 104, 546.Google Scholar
Jackson, J. A. 1987. Active normal faulting and crustal extension. In Coward, M. P., Dewey, J. F. & Hancock, P. L. (Eds) Continental extensional tectonics. GEOL SOC LONDON SPEC PUBL 28, 317.Google Scholar
Katz, H. R. 1952. Zur Geologie von Strindbergs Land (NE-GRØNLAND). MEDDELELSER OM GRØNLAND 111(1), 115 pp.Google Scholar
Knoll, A. H., Hayes, J. M., Kaufman, A. J., Swett, K. & Lambert, I. B. 1986. Secular variation in carbon isotope ratios from Upper Proterozoic successions of Svalbard and East Greenland. NATURE 321, 832–38.CrossRefGoogle ScholarPubMed
Larsen, P. H. & Bengaard, H.-J. 1991. Devonian basin initiation in East Greenland: a result of sinistral wrench faulting and Caledonian extensional collapse. J GEOL SOC LONDON 148, 355–68.CrossRefGoogle Scholar
Lenz, O. 1874. Spezielle Darstellung der geologischen Verhältnisse Ostgrönlands. In Koldeway, K. (Ed.) Die zweite Deutsche Nordpolfahrt in den Jahren 1869 und 1870 unter fiihrung des Kapitdn Karl Koldeway, Band II, Teil III, 481–96. Leipzig: E. A. Brockhaus.Google Scholar
Moncrieff, A. C. M. 1989. The Tillite Group and related rocks of East Greenland: implications for Late Proterozoic palaeogeography. In Gayer, R. A. (Ed.) The Caledonide geology of Scandinavia, 285–97. London: Graham & Trotman.CrossRefGoogle Scholar
Nathorst, A. G. 1901. Bidrag til nördostra Grönlands geologi. GEOL FOREN STOCKHOLM FÖRH 23, 275306.CrossRefGoogle Scholar
Odell, N. E. 1939. The structure of the Kejser Franz Josef Fjord region, North-East Greenland. MEDDELELSER OM GRØNLAND, 119(6), 53 pp.Google Scholar
Odell, N. E. 1944. The petrography of the Franz Josephs Fjord region, North-East Greenland, in relation to its structures. TRANS ROY SOC EDINBURGH 61, 221–46.CrossRefGoogle Scholar
Peucat, J. J., Tisserant, D., Caby, R. & Clauer, N. 1985. Resistance of zircons to resetting in a prograde metamorphic sequence of Caledonian age, East Greenland. CAN J EARTH SCI 22, 330–38.CrossRefGoogle Scholar
Rex, D. C. & Gledhill, A. R. 1974. Reconnaissance geochronology of the infracrustal rocks of Flyverfjord, Scoresby Sund, East Greenland. BULL GEOL SOC DENMARK 23, 4954.Google Scholar
Rex, D. C. & Gledhill, A. R. 1981. Isotopic studies in the East Greenland Caledonides (72°-74°N)—Precambrian and Caledonian ages. GRØNLANDS GEOL UNDERS RAPP 104, 4772.Google Scholar
Sommer, M. 1957a. Geologie von Lyells Land (NE-Gronland). MEDDELELSER OM GRØNLAND 155(2), 157 pp.Google Scholar
Sommer, M. 1957b. Geologische Unterschungen in den Praekam- brischen Sedimenten zwischen Grandjeans Fjord und Bessels Fjord (75°-76°n. Br.) in NE-Grönland. MEDDELELSER OM GRØNLAND 160(2), 56 pp.Google Scholar
Sønderholm, M. & Tirsgaard, H. 1993. Lithostratigraphic framework of the Upper Proterozoic Eleonore Bay Supergroup of East and North-East Greenland. GRØNLANDS GEOL UNDERS BULL 197.Google Scholar
Sønderholm, M., Coilinson, J. D. & Tirsgaard, H. 1989. Stratigraphic and sedimentological studies of the Eleonore Bay Group (Precambrian) between 73°30'N and 76°N in East Greenland. GRØNLANDS GEOL UNDERS RAPP 145, 97102.Google Scholar
Soper, N. J., Strachan, R. A., Holdsworth, R. E., Gayer, R. A. & Greiling, R. O. 1992. Sinistral transpression and the Silurian closure of Iapetus. J GEOL SOC LONDON 149, 871–80.CrossRefGoogle Scholar
Steiger, R. M., Harnik-Soptrajanova, G. & Zimmermann, E. 1976. Isotopic age and metamorphic history of the banded gneiss at Danmarkshavn, East Greenland. CONTRIB MINERAL PETROL 57, 124.CrossRefGoogle Scholar
Steiger, R. M., Hansen, B. T., Schuler, C., Bar, M. T. & Henriksen, N. 1979. Polyorogenic nature of the southern Caledonian fold belt in East Greenland. J GEOLOGY 87, 475–95.CrossRefGoogle Scholar
Strachan, R. A., Holdsworth, R. E., Friderichsen, J. D. & Jepsen, H. F. 1992. Regional Caledonian structure within an oblique convergence zone, Dronning Louise Land, NE Greenland. J GEOL SOC LONDON 149, 359–71.CrossRefGoogle Scholar
Teichert, C. 1933. Unterschungen zum Bau des Kaledonischen Gebirges in Ostgronland. MEDDELELSER OM GRØNLAND 95(1), 121 pp.Google Scholar
Toula, F. 1874. Allgemaine Uebersicht der geologischen Beschaffenheit Ostgrönlands. In Kellaway, K. (Ed.) Die zweite Deutsche Nordpolfahrt in den Jahren 1869 und 1870 unter führung des Kapitdn Karl Koldeway. Band II, Teil III, 475–80. Leipzig: E. A. Brockhaus.Google Scholar
Vidal, G. 1976. Late Precambrian acritarchs from the Eleonore Bay Group and Tillite Group in East Greenland. GRØNLANDS GEOL UNDERS RAPP 78, 19 pp.Google Scholar
Vidal, G. 1979. Acritarchs from the Upper Proterozoic and Lower Cambrian of East Greenland. GRØNLANDS GEOL UNDERS BULL 134, 40 pp.Google Scholar
Wegmann, C. E. 1935. Zur Deutung der Migmatite. GEOL RUNDSCH 26, 305–50.CrossRefGoogle Scholar
Wenk. E. & Haller, J. 1953. Geological explorations in the Petermann region, western part of Fraenkels Land, East Greenland. MEDDELELSER OM GRØNLAND 111(3), 48 pp.Google Scholar
Wordie, J. M. 1927. The Cambridge expedition to East Greenland 1926, V, Geology. GEOGRAPH J 70, 252–53.CrossRefGoogle Scholar
Wordie, J. M. & Whittard, W. F. 1930. A contribution to the geology of the country between Petermann Peak and Kjerulf Fjord, East Greenland. GEOL MAG 67, 145–58. pp.CrossRefGoogle Scholar