Dm. Harwood et al., Diatom biostratigraphy and age of the Pliocene Sorsdal Formation, VestfoldHills, East Antarctica, ANTARCT SCI, 12(4), 2000, pp. 443-462
Fossil marine diatom assemblages from the Sorsdal Formation, a deposit of d
iatomaceous sand from Marine Plain in the Vestfold Hills, protide age and p
alaeoenvironmental information from a Pliocene coastal setting in East Anta
rctica. Benthic and meroplanktic diatom taxa suggest deposition in a shallo
w coastal embayment with water depths of 20-25 m. Diatom biostratigraphy in
dicates that the Sorsdal Formation belongs to the Fragilariopsis barronii Z
one (4.5 to 4.1 Ma), through correlation to reference sections in the Ross
Sea and Southern Ocean. Features of the other biota suggest higher sea-surf
ace temperatures and reduced sea-ice cover, consistent with global records
of higher sea level.