Palynomorphs from a sediment core reveal a sudden remarkably warm Antarctica during the middle Miocene

• Published in: Geology
• Main Authors: Warny, S., Askin, R. A., Hannah, M. J., Mohr, B. A. R., Raine, J. I., Harwood, D. M., Florindo, F., SMS Science Team
• Other Authors: Warny, S.; Department of Geology and Geophysics, and Museum of Natural Science, E235 Howe-Russell, Louisiana State University, Baton Rouge, Louisiana 70803, USA, Askin, R. A.; Department of Geology and Geophysics, and Museum of Natural Science, E235 Howe-Russell, Louisiana State University, Baton Rouge, Louisiana 70803, USA, Hannah, M. J.; School of Geography, Environment and Earth Sciences, Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington, New Zealand, Mohr, B. A. R.; Museum of Natural History, Collections, Invalidenstrasse 43, 10115 Berlin, Germany, Raine, J. I.; GNS Science, PO Box 30368, Lower Hutt, New Zealand, Harwood, D. M.; Department of Geosciences, and ANDRILL Science Management Office, 214 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0340, USA, Florindo, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, SMS Science Team; http://andrill.org/projects/sms/team.html, Department of Geology and Geophysics, and Museum of Natural Science, E235 Howe-Russell, Louisiana State University, Baton Rouge, Louisiana 70803, USA, School of Geography, Environment and Earth Sciences, Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington, New Zealand, Museum of Natural History, Collections, Invalidenstrasse 43, 10115 Berlin, Germany, GNS Science, PO Box 30368, Lower Hutt, New Zealand, Department of Geosciences, and ANDRILL Science Management Office, 214 Bessey Hall, University of Nebraska–Lincoln, Lincoln, Nebraska 68588-0340, USA, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia, http://andrill.org/projects/sms/team.html
• Format: Article in Journal/Newspaper
• Language: English
• Published: Geological Society of America 2009
• Subjects: Middle Miocene Climatic Optimum; ANDRILL; Antarctica; Palynomorphs; 04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating; processes; transport; 04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy; Antarctic; Ross Sea; Antarc*; Sea ice
• Online Access: http://hdl.handle.net/2122/5231; https://doi.org/10.1130/G30139A.1

An exceptional triple palynological signal (unusually high abundance of marine, freshwater, and terrestrial palynomorphs) recovered from a core collected during the 2007 ANDRILL (Antarctic geologic drilling program) campaign in the Ross Sea, Antarctica, provides constraints for the Middle Miocene Climatic Optimum. Compared to elsewhere in the core, this signal comprises a 2000-fold increase in two species of dinoflagellate cysts, a synchronous fivefold increase in freshwater algae, and up to an 80-fold increase in terrestrial pollen, including a proliferation of woody plants. Together, these shifts in the palynological assemblages ca. 15.7 Ma ago represent a relatively short period of time during which Antarctica became abruptly much warmer. Land temperatures reached 10 °C (January mean), estimated annual sea-surface temperatures ranged from 0 to 11.5 °C, and increased freshwater input lowered the salinity during a short period of sea-ice reduction. Published 955-958 1.8. Osservazioni di geofisica ambientale 2.2. Laboratorio di paleomagnetismo JCR Journal reserved