Late Quaternary foraminifera from raised deposits of the Cape Royds-Cape Barne area, Ross Island, Antarctica

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Abstract
Late Quaternary marine deposits crop out at elevations as high as 60 m above sea level along the Victoria Land coastline of Antarctica and on the lower flanks of late Cenozoic volcanic islands of McMurdo Sound. These sediments consist of unconsolidated or ice-cemented gravels, sands and silts, often having an appreciable biogenic content. Outcrops along the western coastline of Ross Island between Cape Royds and Cape Barne provided material for the earliest paleontological studies in this sector of Antarctica. Frederick Chapman described a foraminiferal assemblage of 22 species from two samples collected in this area between 1907 and 1909. Examination of new collections from these localities increases the recorded number of late Quaternary taxa to 45 genera and 88 species (3 agglutinated, 84 calcareous benthic and 1 planktonic species). A revision of Chapman''s generic and specific assignations is provided. U/Th dating of skeletal carbonate suggests an age of 120,000 .+-. 6,000 yr for the biogenic components. We conclude that subsequent to this date these marine sediments were frozen into an advancing, grounded, ice shelf and transported to their present location just above sea level. Redeposition apparently involved little modification of the original sediment, macrofauna and microfauna. These foraminiferal assemblages are similar to Holocene assemblages of the southwest Ross Sea.