Geological fieldwork on Deception Island and King George Island ...

Askin, R.A., D.H. Elliot, J.D. Stilwell, and W.J. Zinsmeister. 1991. Stratigraphy and Paleontology of Campanian and Eocene sediments, Cockburn Island, Antarctic Peninsula. South American Journal of Earth Sciences, 4(1/2), 99-117 Dettmann, M.E., D.T. Pocknall, E.G. Romero, and M. del Carmen Zamaloa. 1990. Nothofagidites Erdtman ex Potonié, 1960; a catalogue of species with notes on the paleogeographic distribution of Nothofagus BI. (Southern Beech). New Zealand Geological Survey Paleontological Bulletin, 60, 1-79. Harwood, D.M. 1988. Upper Cretaceous and Lower Paleocene diatom and silicoflagellate biostratigraphy of Seymour Island, eastern Antarctic Peninsula. In R.M. Feldmann and M.O. Woodburne (Eds.), Geology and paleontology of Seymour Island, Antarctic Peninsula. (Geological Society of America Memoir 169.) Boulder, Colorado: Geological Society of America. Sadler, P.M. 1988. Geometry and stratification of uppermost Cretaceous and Paleogene units on Seymour Island, northern Antarctic

Geological fieldwork on Deception Island and King George Island, South Shetland Islands RANDALL A. KELLER

College of Oceanography Oregon State University Corvallis, Oregon 97331

Peninsula. In R.M. Feldmann and M.O. Woodburne (Eds.), Geology and paleontology of Seymour Island, Antarctic Peninsula. (Geological Society of America Memoir 169.) Boulder, Colorado: Geological Society of America. Torres, T., and Meon, H. 1990. Preliminary palynological study of Fossil Hill, Fildes Peninsula, King George Island, Antarctica. Serie Cientifica INACH, 40, 21-39. (In Spanish) Wrenn, J.H., and G.F. Hart. 1988. Paleogene dinoflagellate cyst biostratigraphy of Seymour Island, Antarctica. In R.M. Feldmann and

M.O. Woodburne (Eds.), Geology and paleontology of Seymour Island, Antarctic Peninsula. (Geological Society of America Memoir 169.) Boulder, Colorado: Geological Society of America. Zinsmeister, WJ., and H.H. Camacho. 1982. Late Eocene (to possibly earliest Oligocene) molluscan fauna of the La Meseta Formation of Seymour Island, Antarctica Peninsula. In Craddock (Eds.), Antarctic geoscience. Madison: University of Wisconsin Press.

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On 6 January 1991, the Fourth Polish Geodynamical Expedi tion to West Antarctica departed Montevideo, Uruguay aboard the ocean-going tug Neptunia (Polish Ship Salvage Company, Gdynia). By kind invitation of Aleksander Guterch (Institute of Geophysics, Polish Academy of Sciences, Warsaw) and Krzysztof Birkenmajer (Institute of Geological Sciences, Polish Academy of Sciences, KrakOw), I was able to participate in that expedition. The expedition spent 6 weeks in the Bransfield Strait and South Shetland Islands conducting geophysical surveys and geological fieldwork at various locations. I was a member of a geological field party that spent 17 days on Deception Island, a large volcano in the Bransfield Strait (figure). All of Deception Island is thought to be less than 700,000 years old, and many areas are still warm from volcanic eruptions as recent as 1970 (Smellie 1988). Professor Birkenmajer mapped the geology of the island while I collected samples of volcanic rocks for geochemical and petrological analyses (see Keller, Fisk, and White, Antarctic Journal, this issue). Our field party then moved to the area of Lions Rump on King George Island (figure) for 14 days. This area contains exposures of glacial sediments interbedded with volcanic arc rocks of Tertiary age and has been the subject of intense geological study (e.g., Porebski and Gradzinski 1987; Birkenmajer, Soliani, and Kawashita 1989). I sampled some of the volcanic arc rocks for geochemical analyses and comparison to our samples from the younger volcanoes (such as Deception Island) associated with extension in the Bransfield Strait (see Keller, Fisk, and White, Antarctic Journal, this issue).

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Geography and bathymetry of the Bransfield Strait region. Land areas are shaded. Bathymetry contoured in kilometers (km). Locations of 1990-1991 geological fieldwork described in this article are Deception Island and Lions Rump on King George Island.

This work was supported by a Fulbright Research Fellowship from the U.S. Information Agency, and National Science Foundation grant DPP 88-17126 to M.R. Fisk.

References Birkenmajer, K., E. Soliani, Jr., and K. Kawashita. 1989. Geochronology of Tertiary glaciations on King George Island, West Antarctica. Bulletin of the Polish Academy of Sciences, Earth Sciences, 37, 27-48. Keller, R.A., M.R. Fisk, and W.M. White. 1991. Geochemistry of Quaternary volcanism in the Bransfield Strait and South Shetland Islands: Preliminary results. Antarctic Journal of the U.S., 26(5). Porebski, S.J., and R. Gradzinski. 1987 Depositional history of the Polonez Cove Formation (Oligocene), King George Island, West Antarctica: A record of continental glaciation, shallow-marine sedimentation and contemporaneous volcanism. Studia Geologica Polonica, 93(7), 7-62. Smellie, J.L. 1988, Recent observations on the volcanic history of Deception Island, South Shetland Islands. British Antarctic Survey Bulletin, 81, 83-85.

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