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The geological significance of some Triassic microfossils from the South Orkney Islands, Scotia Ridge

Published online by Cambridge University Press:  01 May 2009

I. W. D. Dalziel ,
D. H. Elliot ,
D. L. Jones ,
J. W. Thomson ,
M. R. A. Thomson ,
N. A. Wells  and
W. J. Zinsmeister
I. W. D. Dalziel
Affiliation:
Lamont Doherty Geological Observatory, Columbia University, New York, NY 10027
D. H. Elliot
Affiliation:
Institute of Polar Studies and Department of Geology and Mineralogy, The Ohio State University, Columbus, Ohio 43210
D. L. Jones
Affiliation:
US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025
J. W. Thomson
Affiliation:
British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge CB3 0ET, U.K.
M. R. A. Thomson
Affiliation:
British Antarctic Survey, Natural Environment Research Council, Madingley Road, Cambridge CB3 0ET, U.K.
N. A. Wells
Affiliation:
Institute of Polar Studies and Department of Geology and Mineralogy, The Ohio State University, Columbus, Ohio 43210
W. J. Zinsmeister
Affiliation:
Institute of Polar Studies and Department of Geology and Mineralogy, The Ohio State University, Columbus, Ohio 43210
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Summary

Late Triassic Radiolaria have been recovered from a bedded chert collected early in 1977 in the South Orkney islands. This is the first reliable palaeontological evidence for the age of the so-called basement complex that forms most of the exposed rock of a microcontinent on the southern limb of the Scotia Ridge. The fossils place a lower limit on the age of deformation of at least part of the complex as post-Karnian or Norian. The basement is overlain by undeformed Jurassic to Cretaceous conglomerates, which suggests this event took place during the early Mesozoic Gondwanian orogeny.

The new data are consistent with the interpretation that the basement complex of the South Orkney Islands represents part of a subduction complex and was accreted to the Pacific margin of Gondwanaland during the late Triassic or early Jurassic time.

Type
Articles
Information
Geological Magazine , Volume 118 , Issue 1 , January 1981 , pp. 15 - 25
Copyright
Copyright © Cambridge University Press 1981

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References

Adie, R. J. 1957. The petrology of Graham Land: III. Metamorphic rocks of the Trinity Peninsula Series. Scient. Rep. Falkd. Isl. Depend. Surv. 20.Google Scholar
Adie, R. J. 1964. Stratigraphic correlation in western Antarctica. In Antarctic Geology (ed. Adie, R. J.), pp. 307–13. Amsterdam: North-Holland.Google Scholar
Barker, P. F. & Griffiths, D. J. 1972. The evolution of the Scotia Ridge and Scotia Sea. Phil. Trans. R. Soc. Lond. Ser. A, 271 151–83.Google Scholar
Barker, P. F., Dalziel, I. W. D. & others. 1976. The evolution of the southeastern Atlantic Ocean Basin: Results of Leg 36, Deep Sea Drilling Project. In Initial Reports of Deep Sea Drilling Project, vol. 36 (ed. Barker, P. F., Dalziel, I. W. D. et al. ), pp. 993–1014. Washington, D.C.: U.S. Government Printing Office.Google Scholar
Cordini, I. R. 1955. Contribución al conocimiento del sector antártico argentino. Publnes Inst. antárt. argent. 1.Google Scholar
Dalziel, I. W. D. 1971. Structural studies in the Scotia arc: the South Orkney Islands: R/V Hero Cruise 71–1. Antarct. J. U.S. 6 124–6.Google Scholar
Dalziel, I. W. D. in press. The pre-Jurassic history of the Scotia arc: a review and progress report. In Antarctic Geoscience (ed. Craddock, C.). Madison: University of Wisconsin Press.Google Scholar
Dalziel, I. W. D. & Elliot, D. H. 1971. Evolution of the Scotia Arc. Nature, Lond. 223 246–52.CrossRefGoogle Scholar
Dalziel, I. W. D. & Elliot, D. H. 1973. The Scotia Arc and Antarctic Margin. In The Ocean Basins and Margins: 1. The South Atlantic (ed. Nairn, A. E. M. & Stehli, F. G.), pp. 171–245. New York: Plenum Press.Google Scholar
Dalziel, I. W. D., Elliot, D. H., Thomson, J. W., Thomson, M. R. A., Wells, N. A. & Zinsmeister, W. J. 1977. Geologic studies in the South Orkney Islands: R/V Hero Cruise 77–1. Antarct. J. U.S. 12 98–101.Google Scholar
Dalziel, I. W. D. & Forsythe, R. D. 1978. Du Toit's ‘Samfrau geosyncline’ and plate tectonics. Geol. Soc. Am. Abstracts with Programs 10, 385.Google Scholar
De Wit, M. J. 1977. The evolution of the Scotia Arc as a key to the reconstruction of southwestern Gondwanaland. Tectonophysics 37 53–81.CrossRefGoogle Scholar
Douglas, R. C. & Nestell, M. K. 1976. Late Paleozoic Foraminifera from southern Chile. Prof. Pap. U.S. geol. Surv. 858.Google Scholar
du Toit, A. L. 1937. Our wandering continents. Edinburgh, Scotland: Oliver and Boyd.Google Scholar
Edwards, C. W. 1979. Further paleontological evidence of Triassic sedimentation in West Antarctica. In Antarctic Geoscience (ed. Craddock, C.). Madison: University of Wisconsin Press.Google Scholar
Elliot, D. H. & Wells, N. A. in press. Mesozoic alluvial fans of the South Orkney Islands. In Antarctic Geoscience (ed. Craddock, C.). Madison: University of Wisconsin Press.Google Scholar
Forsythe, R. D. & Mpodozis, C. 1979. El Archipelago Madre de Dios, Patagonia Occidental, Magallanes: rasgos generales de la estratigrafia y estructura del ‘basamento’ pre-Jurasico superior. Revta geol. Chile, 7 13–29.Google Scholar
Garrison, R. E. 1974. Radiolarian cherts, pelagic limestones and igneous rocks in eugeosynclinal assemblages. In Pelagic Sediments: On Land and Under the Sea (ed. Hs, K. J.ü & Jenkyns, H. C.), pp. 367–99. Oxford, England: Blackwell. (International Association of Sedimentologists, Special Publication, No. 1.)Google Scholar
Goddard, E. N., Trask, P. D., De Ford, R. D., Rove, O. N., Singewald, J. T. & Overbrick, R. M. 1970. Rock Color Chart. Boulder, Colorado: Geol. Soc. America.Google Scholar
Grange, J. 1848. Voyage au pole sud et dans l'Océanie sur les corvettes l'Astrolabe et la Zélée exécuté pendant les années 1837–1840 sous le commandement de M. J., Dumont d'Urville. Géologie, minéralogie et géographie physique du voyage, vol. 1. Paris: Gide et Cie.Google Scholar
Grikurov, G. E., Krylov, A. Ya. & Silin, Yu. I. 1967. Absolute age of some rocks from the Scotia Arc and Alexander I Land (Western Antarctica). Dokl. (Proc.) Acad. Sci. USSR, Geol. Sci. Sect. 172 19–22.Google Scholar
Hawkes, D. D. 1962. The structure of the Scotia Arc. Geol. Mag. 99 85–91.CrossRefGoogle Scholar
Hillhouse, J. W. 1977. Paleomagnetism of the Triassic Nikolai Greenstone, south-central Alaska. Can. J. Earth Sci. 14 2578–92.CrossRefGoogle Scholar
Holtedahl, O. 1929. On the geology and physiography of some Antarctic and Sub-Antarctic islands. Scient. Results Norw. Antarct. Exped. 3.Google Scholar
Irwin, W. P., Jones, D. L. & Kaplan, T. A. 1978. Radiolarians from pre-Nevadan rocks of the Klamath Mountains, California and Oregon. In Mesozoic Paleogeography of the Western United States, vol. 2 (eds Howell, D. G. & McDougall, K.), pp. 303–10. Los Angeles: The Pacific Sect. Soc. Econ. Paleontologists and Mineralogists.Google Scholar
Jones, D. L., Silberling, N. J. & Hillhouse, J. W. 1977. Wrangellia, a displaced terrane in northwestern North America. Can. J. Earth Sci. 14 2565–77.CrossRefGoogle Scholar
Kempe, D. R. C. 1973. Rocks from Antarctica: the Discovery collection in the British Museum (Natural History). Bull. Br. Mus. Nat. Hist. (Miner.) 2 337–76.Google Scholar
Matthews, D. H. 1959. Aspects of the geology of the Scotia Arc. Geol. Mag. 96 425–41.CrossRefGoogle Scholar
Matthews, D. H. & Maling, D. H. 1967. The geology of the South Orkney Islands: I. Signy Island. Scient. Rep. Falkld Isl. Depend. Surv. 25.Google Scholar
Miller, J. A. 1960. Potassium-argon ages of some rocks from the South Atlantic. Nature, Lond. 187 1019–1020.CrossRefGoogle Scholar
Pessagno, E. A. Jr, Finch, J. W. & Abbott, P. L. in press. Upper Triassic Radiolaria from the San Hipolito Formation, Baja California. Micropaleontology.Google Scholar
Pessagno, E. A. Jr, & Newport, R. L. 1972. A technique for extracting Radiolaria from radiolarian cherts. Micropaleontology 18 231–4.CrossRefGoogle Scholar
Pirie, J. H. H. 1905. On the graptolite-bearing rocks of the South Orkneys. Proc. R. Soc. Edinb. 25 463–70.CrossRefGoogle Scholar
Pirie, J. H. H. 1906. Sledge and boat journeys. In The Voyage of the Scotia. Being the Record of a Voyage of Exploration in the Antarctic Seas (eds Brown, R. N. R., Mossman, R. C. & Pirie, J. H. H.), pp. 145–79. Edinburgh, London: Blackwood.Google Scholar
Pirie, J. H. H. (unpublished). Geology of the South Orkneys. Scottish National Antarctic Expedition Reports, 1–10.Google Scholar
Rex, D. C. 1976. Geochronology in relation to the stratigraphy of the Antarctic Pensinsula. Bull. Brit. Antarct. Surv. 43 49–58.Google Scholar
Rex, D. C. & Baker, P. E. 1973. Age and petrology of the Cornwallis Island granodiorite. Bull. Brit. Antarct. Surv. 32 55–61.Google Scholar
Rivano, S. & Cortés, R. 1975. Nota preliminar sobre el hallazgo de rocas metamórphicas en la Isla Smith (Shetland del Sur), Antártico Chilena. Ser. cient. Inst. antárt. chil. 3 9–14.Google Scholar
Thomson, J. W. 1968. The geology of the South Orkney Islands: II. The Petrology of Signy Island. Scient. Rep. Brit. Antarc. Surv. 62.Google Scholar
Thomson, J. W. 1971. The geology of Matthews Island, South Orkney Islands. Bull. Brit. Antarct. Surv. 26 51–7.Google Scholar
Thomson, J. W. 1973. The geology of Powell, Christoffersen and Michelsen Islands, South Orkney Islands. Bull. Brit. Antarct. Surv. 33 and 34 137–67.Google Scholar
Thomson, J. W. 1974. The geology of the South Orkney Islands: III. Coronation Island. Scient. Rep. Brit. Antarct. Surv. 86.Google Scholar
Thomson, M. R. A. 1975(a). Fossils from the South Orkney Islands: II. Matthews Island. Bull. Brit. Antarct. Surv. 40 75–7.Google Scholar
Thomson, M. R. A. 1975(b). New palaeontological and lithological observations in the Legoupil Formation, north-west Antarctic Peninsula. Bull. Brit. Antarct. Surv. 41 and 42 169–85.Google Scholar
Thomson, M. R. A. & Willey, L. E. 1975. Fossils from the South Orkney Islands: I. Coronation Island. Bull. Brit. Antarct. Surv. 40 15–21.Google Scholar
Tilley, C. E. 1935. Report on rocks from the South Orkney Islands. ‘Discovery’ Rep. 10 383–90.Google Scholar
Tyrrell, G. W. 1945. Report on rocks from West Antarctica and the Scotia Arc. ‘Discovery’ Rep. 23 37–102.Google Scholar
Wells, N. A. in press. Mesozoic alluvial fan conglomerates and other sedimentary rocks of the South Orkney Islands, Antarctica. Inst. polar studies Rep. No. 71.Google Scholar
West, S. M. 1968. Petrography of metamorphic rocks from the Inaccessible and Larsen Islands, South Orkney Islands. Bull. Brit. Antarct. Surv. 18 45–57.Google Scholar
Wilckens, C. 1933. Der Südantillen-Bogen. Geol. Rdsch. 25 320–35.CrossRefGoogle Scholar
Willey, L. E. 1973. Belemnites from south-eastern Alexander Island. The occurrence of the family Belemnopseidae in the Upper Jurassic and Lower Cretaceous. Bull. Brit. Antarct. Surv. 36 33–59.Google Scholar