Palaeontologic Characterisation and Analysis of the AND-1B Core, ANDRILL McMurdo Ice Shelf Project, Antarctica

Fossils provide key data sets for the interpretation of the AND-1B core. Calcareous plankton and benthos provide the basis for palaeoenvironmental interpretations of both surface and bottom waters. Calcareous fossils are rare throughout, but occurrences noted are significant. Some calcareous fossils provide potential for age control via 86Sr/87Sr, and palaeoenvironmental information may come from Mg/Ca ratios as well as oxygen and carbon isotopes. Organic-walled microfossils provide an index of reworking and transport, as well as the identifi cation of a possible in situ Pliocene assemblage of previously unknown marine palynomorphs. Diatoms are abundant in the core, with diatom-rich sediments constituting nearly half the upper 600 m of core, subdivided into 13 diatomaceous units, ranging in thickness from under 1 m to nearly 100 m. Diatoms provide biostatigraphic age control, but calibration to the Southern Ocean zonation is limited by ecologic exclusion of many taxa and previously undocumented diachrony among other taxa. A new, high-resolution diatom biostratigraphy for the Antarctic continental shelf is now under development. Diatoms provide the basis for numerous palaeoenvironmental applications, including providing a proxy for palaeotemperature and palaeo-sea ice, as well as palaeoproductivity. All results presented here are preliminary, and interpretations should be considered tentative, pending quantitative and more detailed qualitative follow-up analyses