Range chart of calcareous nannofossils in sediment core CRP-2A (Table 1)

• Main Authors: Watkins, David K, Villa, Giuliana
• Format: Dataset
• Language: English
• Published: PANGAEA 2000
• Subjects: 14.2 km at 096° true from Cape Roberts; Abundance estimate; Bicolumnus ovatus; Cape Roberts Project; Chiasmolithus altus; Core wireline system; CRP; CRP-2; CRP-2A; CWS; DEPTH; sediment/rock; Dictyococcites bisectus; Dictyococites daviesii; Dictyococites hesslandii; Dictyococites productus; Isthmolithus recurvus; Nannofossil abundance; Nannofossils indeterminata; Nannofossils preservation; off Cape Roberts; Ross Sea; Antarctica; Reticulofenestra hampdenensis; Reticulofenestra minuta; Reticulofenestra minutula; Reticulofenestra oamaruensis; Reticulofenestra umbilicus; Sampling/drilling from ice; Species richness; Sphenolithus sp.; Thoracosphaera heimii; Thoracosphaera saxea; Thoracosphaera sp.; Triquetrorhabdulus sp; Cape Roberts; Antarc*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.144690; https://doi.org/10.1594/PANGAEA.144690

Rare calcareous nannofossils from the Cape Roberts Project drillhole CRP-2A indicate that this area was episodically invaded by marginal oceanic surface waters during the late and late early Oligocene. These depauperate assemblages lack most of the biostratigraphic index fossils for the Oligocene, but do provide two datum that aid in constraining the age of the section: the last appearance datum (LAD) of Dictyococcites bisectus (23.9 Ma) at 149.28 mbsf and the LAD of Chiasmolithus altus (26.1 Ma) at 412.25 mbsf. Calcareous nannofossil assemblages stratigraphically below c. 440 mbsf contain conspicuous evidence of reworking of older (late Eocene) specimens that renders age determination difficult.