Carbon cycle change in the Eocene ...
The transition from the extreme global warmth of the early Eocene 'greenhouse' climate ~55 million years ago to the present glaciated state is one of the most prominent changes in Earth's climatic evolution. It is widely accepted that large ice sheets first appeared on Antarctica ~34...
| Main Authors: | , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
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PANGAEA
2005
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.738240 https://doi.pangaea.de/10.1594/PANGAEA.738240 |
| Summary: | The transition from the extreme global warmth of the early Eocene 'greenhouse' climate ~55 million years ago to the present glaciated state is one of the most prominent changes in Earth's climatic evolution. It is widely accepted that large ice sheets first appeared on Antarctica ~34 million years ago, coincident with decreasing atmospheric carbon dioxide concentrations and a deepening of the calcite compensation depth in the world's oceans, and that glaciation in the Northern Hemisphere began much later, between 10 and 6 million years ago. Here we present records of sediment and foraminiferal geochemistry covering the greenhouse-icehouse climate transition. We report evidence for synchronous deepening and subsequent oscillations in the calcite compensation depth in the tropical Pacific and South Atlantic oceans from ~42 million years ago, with a permanent deepening 34 million years ago. The most prominent variations in the calcite compensation depth coincide with changes in seawater oxygen isotope ratios of ... : Supplement to: Tripati, Aradhna K; Backman, Jan; Elderfield, Henry; Ferretti, Patrizia (2005): Eocene bipolar glaciation associated with global carbon cycle changes. Nature, 436, 341-346 ... |
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