The Sabrina microfloras of East Antarctica: Late Cretaceous, Paleogene or reworked?

Abstract

The published latest Palaeocene to Early–Middle Eocene age limits of the Sabrina microfloras, offshore Aurora Subglacial Basin, East Antarctica, largely depend on 1970s age-range data for fossil pollen and spore species in the continental margin basins of southern Australia. This paper uses updated biostratigraphical data from southern Australia, including the basins closest to the Aurora Basin throughout the Late Cretaceous and Paleogene, to propose that the age of the terrestrial component of the Sabrina microfloras is Campanian to Maastrichtian, not Paleogene. However, the revised age limits do not preclude these microfloras being redeposited more or less intact during the development and expansion of ice-sheets on East Antarctica, i.e. most probably during the late Paleogene based on other evidence from East Antarctica.

Keywords:

• East Antarctica
• Sabrina coast
• glaciation
• Aurora Subglacial Basin
• Sabrina microfloras
• Paleogene
• Late Cretaceous
• Maastrichtian
• Campanian

Acknowledgements

I am grateful to my colleague Dr Alan Partridge (Biostrata Ltd.) for bringing Smith et al.’s (2019) paper to my attention and for subsequent robust discussion on the implications for Late Cretaceous glaciation in East Antarctica. Professor Sophie Warny (Louisiana State University) was immensely helpful in redefining the argument presented in the first draft, as was Dr C. (Katy) Smith (University of South Florida) for formally describing new species shared between Antarctica and Australia. My thanks indeed to both. The conclusions (and caveats) in this comment, however, are my own.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Notes on contributors

Mike Macphail

MIKE MACPHAIL is a palynostratigrapher with some 40 years industry and academic experience (and c 100 published papers) on the Mesozoic-Cenozoic palynostratigraphy of Australia and adjacent landmasses including Antarctica, New Zealand and South America (Argentina, Falkland Islands). In association with other Australian colleagues, he has helped develop the pollen and spore-based biostratigraphies currently used to date and correlate Australian Upper Cretaceous to Neogene terrestrial and offshore sedimentary sequences as well undertaking the pollen-analysis of Late Quaternary, prehistoric Indigenous and colonial era archaeological sites across southern Australia.