Abstract
Palynological analyses of 12 samples from the Cape Melville Formation, which crops out on easternmost King George Island, Antarctica, provide new information on the type of vegetation that covered the South Shetland Islands during the early Miocene Melville Glaciation, c. 23–21 Ma. The assemblage recovered was mostly characterised by in situ algae such as leiospheres along with acanthomorph acritarchs, both glacial indicators. The sparse in situ terrestrial palynomorph assemblage included tundra-indicative moss spores Coptospora sp., rare podocarp conifer and various angiosperm pollen. The latter includes pollen of several species of Nothofagidites, plus rare Asteraceae, Caryophyllaceae (Colobanthus-type) and Chenopodipollis. The majority of the palynomorphs recovered are interpreted as reworked, denoting glacial scouring and redeposition from various sites in the Antarctic Peninsula and the South Shetland Islands. These reworked palynomorphs are of Permian to Paleogene age. This reworked component provides insight into the potential sources of reworking, and is consistent with multiple cycles of glacial advances to the Melville Peninsula at the time of deposition. The penecontemporaneous palynomorphs recovered provide new data on the climatic regime and glacial intensification during the early Miocene on King George Island.
Acknowledgements
The authors would like to thank the Institute of Geological Sciences, Polish Academy of Sciences, for providing the samples. Field assistance by Marcin Klisz and Mariusz Potocki during the 2007 expedition and Grzegorz Zieliński during the 2009 expedition is greatly appreciated. The authors are grateful to the anonymous reviewers for their review of this manuscript. Thanks are extended to HESS corporation (D. Pocknall) for the donation of the Stratabugs software and to HESS consultant (P. Griggs) and intern (M. Thomas) for training the Center for Excellence in Palynology (CENEX) research group.
Disclosure statement
The work presented here is strictly academic in nature and was done as part of the training of a graduate student. The authors do not have any financial interest arising from this study.
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Notes on contributors
Sophie Warny
Sophie Warny is an associate professor of palynology in the Department of Geology and Geophysics, and a curator at the Museum of Natural Science at Louisiana State University (LSU) in Baton Rouge, Louisiana, USA. Sophie has a long history with American Association of Shragigraphic Palynologists (AASP) as she won the AASP Student Award in 1996. Sophie received her PhD from the Université Catholique de Louvain, in Belgium, working with Jean-Pierre Suc; her doctoral dissertation was on the Messinian Salinity Crisis. Since graduating, Sophie has been working on Antarctic sediments that were acquired via the ANDRILL SMS and SHALDRIL projects. In 2011, she received the National Science Foundation CAREER award to support her research in Antarctica. In addition to her research, Sophie teaches historical geology, palaeobotany and micropalaeontology. Sophie currently has a research group that is composed of three PhD students, three masters students and one undergraduate, all working on sections ranging in age from Cretaceous to Cenozoic. Since being hired at LSU, Sophie has graduated nine students; all of which are now employed in the oil and gas industry with Hess, BP, Devon, Chevron, BHP Billiton Petroleum and EOG.
C. Madison Kymes
C. Madison Kymes is currently pursuing an MSc in palynology in the Department of Geology and Geophysics at Louisiana State University, Baton Rouge, Louisiana, USA under the direction of Sophie Warny. Madison was born in Shreveport, Louisiana, but spent the majority of his life growing up in Madison, Mississippi, where he recently interned as an environmental geologist.
Rosemary A. Askin
Rosemary A. Askin is currently pursuing research in the palynology of Antarctica and consulting in Jackson, Wyoming, USA. She earned her PhD from Victoria University, Wellington, New Zealand. Rosemary has researched and taught in several US universities, most recently at the Byrd Polar Research Center, Ohio State University. Her most recent project there was establishing the US Polar Rock Repository.
Krzysztof P. Krajewski
Krzysztof P. Krajewski is a professor of earth sciences at the Institute of Geological Sciences, Polish Academy of Sciences, in Warsaw, Poland. He obtained his PhD in 1986, and continued research at the Polish Academy of Sciences, the University of Oslo and the University of Oldenburg. Krzysztof completed his DSc in sedimentary petrology and geochemistry in 2001. His scientific interests are on the interactions between biological activity and mineral deposition in carbonate, phosphate and organic carbon-rich sedimentary systems. For more than 20 years, Krzysztof has undertaken geological research in the Arctic, where he has concentrated on Mesozoic phosphorites and petroleum source beds. He is currently involved in research on the evolution of Cenozoic sedimentary systems in Antarctica.
Philip J. Bart
Philip J. Bart is an associate professor in the Department of Geology and Geophysics at Louisiana State University in Baton Rouge, Louisiana, USA. He earned his PhD from Rice University in Houston, working with John Anderson. Philip received the Presidential Early Career Award for Scientists and Engineers in 2001 for his sequence stratigraphical research in Antarctica. He is one of the four current US Representatives to the Standing Scientific Group on GeoSciences of the Scientific Committee on Antarctic Research. Philip's research is on understanding the Cenozoic history of the cryosphere from the perspective of outer continental shelf seismic stratigraphy. The major emphasis of his work has been to constrain the time, frequency, duration and locations of past ice sheet dynamics within the context of possible forcing mechanisms.