Calcareous Microfossils

A significant difference is apparent, both in species abundance and test composition, in assemblages between the two sites. At New Harbour, sample NH 1/A is dominated by arenaceous benthonic foraminifera, sponge spicules and centric (planktonic) diatoms. Common arenaceous foraminifera include Rhabdammina cf. linearis Brady, Rhizammina indivisa Brady, Reophax nodulosus Brady, Haplophragmoides rotulatum (Brady) cf. sphaeriloculus Cushman, Textularia earlandi Parker, Rzehakinidae sp, and Miliammina arenacea (Chapman). A small number of calcareous benthonic foraminiferal taxa including Trifarina earlandi Parr, Fursenkoina daviesi (Chapman & Parr), Robertina sp. and Globocassidulina crassa rossensis Kennett, occur. Also, two juvenile specimens (ostracod) Echinocytheris cf. dasyderma (Brady) have been identified. Sample NH 1/B is dominated by arenaceous taxa, but reduced in diversity compared to sample NH 1/A. Both samples lack Neogloboquadrina pachyderma (Ehrenberg).

In contrast, both Butter Point samples (BP 1/A & BP 1/B) are dominated by calcareous benthonic taxa. Species present include Trifarina earlandi Parr, Ehrenbergina glabra Heron-Allen & Earland, Astrononion antarcticum Parr, Pyrgo williamsoni (Silvestri), Globocassidulina sp. and Fursenkoina daviesi (Chapman & Parr). Most of the New Harbour arenaceous taxa also occur in abundance in the Butter Point samples. Sinstrally coiled Neogloboquadrina pachyderma (Ehrenberg) are common. Ostracod taxa present are Australicythereis polylyca (Muller), Xestoleberis sp, Krithe 2 spp, Australicythereis sp and Trachyleberis sp. cf. Cythere polytrema Brady.