LATE CRETACEOUS EXTINCTION PATTERNS IN ANTARCTICA

New correlations of marine elastic sedimentary rocks exposed within th e James Boss Basin, Antarctica have shown that the mid- to late Cretac eous succession is in excess of 5 km thick. Plotting the ranges of the principal molluscan macrofossils against the revised stratigraphy ind icates that inoceramid bivalves are totally absent, and dimitobelid be lemnites extremely rare, throughout an extensive 1400 m thick Maastric htian succession, These early extinction patterns are interpreted to b e due to both a regional shallowing event and a pronounced phase of hi gh-latitude, Campanian-Maastrichtian cooling. Cool polar bottom waters may have been forming by as early as mid- to late Campanian times.