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Cenozoic sediments penetrated by Hole 511 in the southern part of the Atlantic Ocean (Falkland Plateau, Maurice Ewing Bank) were analyzed for palynomorphs. Upper Eocene and lower Oligocene palynoassemblages are characterized and correlated to synchronous palynoassemblages of similar character from South America, Australia, and New Zealand. The lower Oligocene assemblages show a close relationship to those of other Southern Hemisphere continents except Africa. They also contain reworked Permian and Mesozoic species. The Eocene and early Oligocene climate of the study area was moderately warm and humid, very similar to the southern part of present-day New Zealand; a vertical zonation probably existed. INTRODUCTION Samples of Cenozoic sediments from Sites 511 and 512 were analyzed for palynomorphs. At Site 512, all 58 samples of middle Eocene and Miocene carbonate sediments were almost devoid of spores and pollen. In the Cenozoic sediments penetrated by Hole 511, 52 samples were analyzed over the interval from 3 to 185.5 meters. The 10 samples from the uppermost part of the section (Cores 1-3) contained no spores or pollens. In the lower part of the section (Cores 12-21), the spore and pollen content was also insignificant—analysis yielded no more than 50 specimens per sample. Analysis of 17 samples of sediment from the middle part of the section (Cores 4-12) found a relatively large number of spores and pollen, distributed as shown in Table 1. Preservation of spores and pollen from the Cenozoic sediments at Site 511 is satisfactory, but many specimens are corroded and pitted. The absence or negligible amounts of spores and pollen in some samples cannot yet be explained. It is clearly not related to lithological composition, which remains the same throughout the interval. Stratigraphic subdivision of the Cenozoic sediments at Site 511 was accomplished by means of planktonic foraminifers, nannoplankton, radiolarians, and diatoms. The Paleocene-Eocene (Core 21), upper Eocene (Cores 17-20), and lower Oligocene (Cores 2-16) deposits penetrated are composed of diatomaceous oozes and clays. METHODS Sediments were treated with 10% HC1 to dissolve carbonates, disaggregated by boiling in 10% KOH, elutriated in a pyrophosphate solution (NO4P2O7), separated in a heavy liquid (CdF2) with specific gravity 2.2, and treated by the acetolysis method. Release from silicates was carried out with cold HF. The residue obtained was covered with glycerine. Stable spores and pollen specimens were prepared from a glycerine emulsion on glycerine gel, numbered, and stored in the collection of the Paleofloristic Laboratory of the Geological Institute of the U.S.S.R. Academy of Sciences, No. GIN 3948. Ludwig, W. J., Krasheninnikov, V. A., et al., Init. Repts. DSDP, 71: Washington (U.S. Govt. Printing Office). The study and microphotography were carried out using a Mikrofot D-16 biological microscope, magnification 7 × 60. Microphotographs of spores and pollen are presented in Plates 1-17. CHARACTERISTICS AND COMPARISON OF PALYNOASSEMBLAGES OF THE FALKLAND PLATEAU Only one specimen—a spore of Cyathidites sp. 1— was present in Sample 511-21-1, 40-42 cm (PaleoceneEocene sediments). Upper Eocene Eleven samples were analyzed from upper Eocene sediments (Cores 17-20): 511-20,CC; 511-20-3, 34-36 cm; 511-20-2, 34-36 cm; 511-20-1, 34-36 cm; 511-18,CC; 511-18-2, 34-36 cm; 511-18-1, 34-36 cm; 511-17,CC; 511-17-3, 17-19 cm; 511-17-2, 96-98 cm; 511-17-1, 96-98 cm. The examination showed very small numbers of spores and pollen, from 10 to 40 specimens per sample. Sample 511-18-2, 34-36 cm was the most productive (39 specimens). Despite the small number of isolated microfossils, all samples contain spores of diverse systematic composition: Leiotriletes microadriennis, Cyathidites minor, Stereisporites antiquasporites, Leptolepidites verrucatus, Gleicheniidites senonicus, Cingutriletes australis, Lygodiidites sp., Cyathidites sp. 1, Deltoidospora sp., Concavissimisporites sp., Osmundacidites sp., Lycopodiumsporites sp., Trilites sp. 1, and Form sp. 1 (item 61 in the list of species). Equal amounts of gymnosperm and angiosperm plant pollen are present within the assemblage. Gymnosperms are represented by three genera {Podocarpidites marwickii, Dacrydium cupressinum, and Phyllocladidites mawsonii), angiosperms by two (Nothofagidites asperus, N. sp. 2, Tricolpites sp. 3). Many species of this palynoassemblage, such as G. senonicus, Leiotriletes microadriennis, Cingutriletes australis, Podocarpidites marwickii, Phyllocladidites mawsonii, D. cupressinum, and N. asperus, are representative of Eocene deposits in Argentina (Freile, 1972; Archangelsky, 1972, 1973a, b; Archangelsky and Romero, 1974b; Menendes and Caccavari de Filice, 1975;

Spores and Pollen from Cenozoic Sediments of the Falkland Plateau, Site 511, Deep Sea Drilling Project Leg 71