Strong, C. P. and Webb, P. N. (2000): Oligocene and Miocene Foraminifera from CRP-2/2A, Victoria Land Basin, Antarctica

DSDP 28 270

Strong, C. P.
Institute of Geological & Nuclear Sciences, Lower Hutt, New Zealand

Webb, P. N.
Ohio State University, United States

Oligocene and Miocene Foraminifera from CRP-2/2A, Victoria Land Basin, Antarctica
In: Raine, J. I. (editor), Watkins, D. K. (editor), Studies from the Cape Roberts Project, Ross Sea, Antarctica; scientific report of CRP-2/2A; Part II, Paleontological studies for CRP-2/2A
Universita di Siena. Dipartimento di Scienze della Terra, Siena, Italy
Sparse to moderately abundant foraminiferal assemblages from Oligocene and Lower Miocene sediments in the CRP-2/2A drillhole contain C.27 genera and 42 species of calcareous benthic foraminifera. No planktic or agglutinated taxa were observed. On the basis of their faunal characteristics, four Foraminiferal Units are defined in drillhole succession: Foraminiferal Unit I (26.91-193.95 mbsf), mostly sparse assemblages with Elphidium magellanicum and Cribroelphidium sp.; Foraminiferal Unit II (193.95-342.42 mbsf), mostly moderately abundant assemblages with Cassidulinoides aequilatera and Eponides bradyi; Foraminiferal Unit III (342.42-486.19 mbsf), moderately abundant to sparse assemblages characterised by Cassidulinoides chapmani and Stainforthia sp.; and Foraminiferal Unit IV, Impoverished (486.19-624.15, total depth, mbsf), with mostly barren residues, but with large Milioliidae recorded in situ at various horizons in the drill core. Foraminiferal Units I-IV lack taxa allowing correlation to standard zonal schemes. Inspection of faunal records from CIROS-1 and DSDP 270 indicates that, although the faunas show an overall similarity, CRP-2/2A Foraminiferal Units I-IV are not identifiable at these sites. The units are therefore most likely to reflect local environmental changes, and probably will prove useful for local correlation, but their lateral extent is undertermined. All four assemblages apparently represent various glacially-influenced shelf environments, and appear to reflect a long term deepening trend from Units IV to II, from perhaps inner to mid or outer-shelf depths, followed by return to shallower, inner shelf, conditions for Unit I.
Coverage:Geographic coordinates:
West:-178.3011East: 163.4518

Stratigraphy; Invertebrate paleontology; Antarctic Ocean; Antarctica; assemblages; biostratigraphy; Cape Roberts; Cenozoic; correlation; CRP-2/2A Borehole; Deep Sea Drilling Project; DSDP Site 270; Foraminifera; Invertebrata; Leg 28; microfossils; Miocene; morphology; Neogene; Oligocene; paleo-oceanography; paleoecology; paleoenvironment; Paleogene; preservation; productivity; Protista; Ross Sea; Southern Ocean; species diversity; taxonomy; Tertiary; Victoria Land; Victoria Land Basin;