Middle Eocene bulk sediment, benthic and planktic foraminiferal stable isotope values, relative weight percent CaCO3 content, and palaeomagnetic data from ODP Site 207-1260 ...
Major ice sheets were permanently established on Antarctica approximately 34 million years ago, close to the Eocene/ Oligocene boundary, at the same time as a permanent deepening of the calcite compensation depth in the world's oceans. Until recently, it was thought that Northern Hemisphere gla...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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PANGAEA
2007
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.854335 https://doi.pangaea.de/10.1594/PANGAEA.854335 |
| Summary: | Major ice sheets were permanently established on Antarctica approximately 34 million years ago, close to the Eocene/ Oligocene boundary, at the same time as a permanent deepening of the calcite compensation depth in the world's oceans. Until recently, it was thought that Northern Hemisphere glaciation began much later, between 11 and 5million years ago. This view has been challenged, however, by records of ice rafting at high northern latitudes during the Eocene epoch and by estimates of global ice volume that exceed the storage capacity of Antarctica at the same time as a temporary deepening of the calcite compensation depth 41.6 million years ago. Here we test the hypothesis that large ice sheets were present in both hemispheres 41.6 million years ago using marine sediment records of oxygen and carbon isotope values and of calcium carbonate content from the equatorial Atlantic Ocean. These records allow, at most, an ice budget that can easily be accommodated on Antarctica, indicating that large ice sheets ... : Supplement to: Edgar, Kirsty M; Wilson, Paul A; Sexton, Philip F; Suganuma, Yusuke (2007): No extreme bipolar glaciation during the main Eocene calcite compensation shift. Nature, 448(7156), 908-911 ... |
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