of different lithology. In the absence of diagnostic paleontologic References evidence, this proposal can only be postulated. Finally, the Cretaceous/Tertiary contact may occur at some other, as yet undefined, horizon between the highest ammonite level in the uppermost Lopez de Bertodano Formation and the level of the first Paleocene silicoflagellates in the lowermost Askin, R.A. 1984. Palynological investigations of the James Ross Island Sobral Formation. This is based on the assumption that am- basin and Robertson Island, Antarctic Peninsula. Antarctic Journal of monites were restricted to the Cretaceous. The possibility that the U.S., 19(5), 6 - 7. ammonites may have survived into the Tertiary should not be Harwood, D.M. 1985. Personal communication. ignored, however. Huber, B.T., D.M. Harwood, and P.N. Webb. 1983. Upper Cretaceous microfossil biostratigraphy of Seymour Island, Antarctic Peninsula. Because of the absence of Tertiary indicator species between Antarctic Journal of the U.S., 18(5), 72 - 74. the glauconite bed of the upper Lopez de Bertodano Formation Huber, B.T., D.M. Harwood, and P.N. Webb. 1985. Distribution of micro- and the lower Sobral Formation, a zone of uncertainty, repre- fossils and diagenetic features associated with the Cretaceous - Tertiary senting 73 meters of section, is shown for the location of the boundary on Seymour Island, Antarctic Peninsula. (Unpublished ab- Cretaceous/Tertiary contact on Seymour Island (figure 1). It is stract.) Conference on Rare Events, International Geological Correla- hoped that examination of sample material collected during the tion Programme, Project 199, GWATT, Switzerland, May 20 - 22. 1985 field season will reveal age-diagnostic microfossils in this Macellari, CE., and W.J. Zinsmeister. 1985. Macropaleontology and zone of uncertainty, and therefore lead to further refinement of sedimentology of the Cretaceous/Tertiary boundary in Antarctica. the exact stratigraphic position of the Cretaceous/Tertiary (Unpublished abstract.) Conference on Rare Events, International contact. Geological Correlation Programme, Project 199, GWATT, Switzerland, May 20 - 22. This research was supported by National Science Foundation Zinsmeister, W.J., and C.E. Macellari. 1983. Changes in the macrofossil grants DPP 82-13985 to W.J. Zinsmeister and D.M. Elliot and DPP faunas at the end of the Cretaceous on Seymour Island, Antarctic 82-14174 to Peter N. Webb. Peninsula. Antarctic Journal of the U.S., 18(5), 68 - 69.

Plant fossils from the Ellsworth discovered from several stratigraphic levels in the Polarstar Formation, and together with subsequent contributions Mountains (Schopf 1967; Rigby 1969; Rigby and Schopf 1969) have been concerned primarily with biostratigraphy.

T.N. TAYLOR and E.L. SMOOT

Department of Botany and Institute of Polar Studies Ohio State University Columbus, Ohio 43210 and Department of Biology Hope College Holland, Michigan 49423

Although fragments of fossil plants were collected and re- ported as a result of some of the early explorations in Antarctica (e.g., Scott 1901 - 1904, 1912; Shackleton 1908; Mawson 1911 - 1914), the first comprehensive paleobotanical studies were not completed until later (Halle 1913; Seward 1914). Despite the fact that plant remains are known as early as the Devonian, the most commonly encountered floral elements are the impression specimens of glossopterid leaves that are the dominant vegeta- tion type present in Permian sediments. Plant fossils that were initially collected from sites in the Ellsworth Mountains during the 1961 - 1963 field seasons were reported by Craddock et al. in 1965. These collections, which Figure 1. Glossopteris communis and reproductive organ Plum- consisted mainly of various species of Glossopteris leaves, were steadia sp. (arrow). (x 1.5.)

48 ANTARCTIC JOURNAL The majority of plant remains come from a single locality in the Polarstar Formation (east ridge of Polarstar Peak; 86°10W 77°32S), and an analysis of these will form a component of a volume on the Ellsworth Mountains. The study will not only describe and illustrate the floral elements but will also compare the plants with other Gondwana floras. The specimens come from six stratigraphic levels within a measured section 350 meters thick. The plant remains are pre- served as impressions in a poorly bedded, dark gray to black / argillite. The major floral elements that have been identified include: Glossopteris angustifolia, G. browniana, G. communis, G. damudica, G. indica (figure 1), G. linearis, G. cf.cordata, G. tortuosa (figure 2), G. taen ioptero ides, G. ampla, G. cf.decipiens, G. retifera, Al G. cf.spathulato-cordata, G. stricta, G. cf.conspicua, Plumsteadia sp. (figure 1, arrow), Gangamopteris cf.angustifolia, G. obovata, Ver- tebraria indica, Arberiella sp., Samaropsis sp., Paracalamites cf.aus- tralis, and Raniganjia bengalensis ( figure 3).

Al

Figure 3. Raniganjia bengalensis. (x 2.)

This work was supported by National Science Foundation grant DPP 82-13749.

References

Craddock, C., T.W. Bastien, R.H. Rutford, and J.J. Anderson. 1965. Glossopteris discovered in West Antarctica. Science, 148, 634 - 637. Halle, T.G. 1913. The Mesozoic flora of Graham Land. Wissenschaftliche Ergehennisse der Schwedischen Sud polar-Expedition 1901 - 1903. (Stock- holm), 3(14), 3 - 124. Rigby, J.F. 1969. Permian sphenopsids from Antarctica. (U.S. Geological Survey Professional Paper 613 - F. Washington, D.C.: U.S. Govern- ment Printing Office. Figure 2. Glossopteris tortuosa. (x 2.) Rigby, J. E, and J.M. Schopf. 1969. Stratigraphic implications of Antarctic paleobotanical studies. Gondwana Stratigraphy, 2, Earth Sciences. (In- The Ellsworth Mountain flora compares favorably to other ternational Union of Geological Sciences Symposium 1967.) Mar del Plata, Argentina. Middle and Upper Permian plant assemblages in Antarctica Schopf, J.M. 1967. Antarctic fossil plant collecting during the 1966-1967 (e.g., Ohio Range, Theron Mountains, southern Victoria Land) season. Antarctic Journal of the U.S., 2, 114 - 116. with the possible exception of the presence of Ran iganjia Seward, A.C. 1914. Antarctic fossil plants. British Antarctic ("Terra bengalensis which to date is known only from India and Nova") Expedition, 1910. Natural History Report. (British Museum of Australia. Natural History) Geology, 1(1), 1 - 149.

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