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Ao H, Dupont-Nivet G, Rohling EJ, Zhang P, Ladant JB, Roberts AP, Licht A, Liu Q, Liu Z, Dekkers MJ, Coxall HK, Jin Z, Huang C, Xiao G, Poulsen CJ, Barbolini N, Meijer N, Sun Q, Qiang X, Yao J, An Z. Orbital climate variability on the northeastern Tibetan Plateau across the Eocene-Oligocene transition. Nat Commun 2020; 11:5249. [PMID: 33067447 PMCID: PMC7567875 DOI: 10.1038/s41467-020-18824-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/16/2020] [Indexed: 11/08/2022] Open
Abstract
The first major build-up of Antarctic glaciation occurred in two consecutive stages across the Eocene-Oligocene transition (EOT): the EOT-1 cooling event at ~34.1-33.9 Ma and the Oi-1 glaciation event at ~33.8-33.6 Ma. Detailed orbital-scale terrestrial environmental responses to these events remain poorly known. Here we present magnetic and geochemical climate records from the northeastern Tibetan Plateau margin that are dated precisely from ~35.5 to 31 Ma by combined magneto- and astro-chronology. These records suggest a hydroclimate transition at ~33.7 Ma from eccentricity dominated cycles to oscillations paced by a combination of eccentricity, obliquity, and precession, and confirm that major Asian aridification and cooling occurred at Oi-1. We conclude that this terrestrial orbital response transition coincided with a similar transition in the marine benthic δ18O record for global ice volume and deep-sea temperature variations. The dramatic reorganization of the Asian climate system coincident with Oi-1 was, thus, a response to coeval atmospheric CO2 decline and continental-scale Antarctic glaciation.
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Affiliation(s)
- Hong Ao
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
- CAS Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi'an, China.
- Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China.
| | - Guillaume Dupont-Nivet
- Université de Rennes, CNRS, Géosciences Rennes, UMR, 6118, Rennes, France.
- Key Laboratory of Orogenic Belts and Crustal Evolution, Peking University, Beijing, China.
- Universität Potsdam, Institute of Geosciences, Potsdam, Germany.
| | - Eelco J Rohling
- Research School of Earth Sciences, Australian National University, Canberra, Australia
- Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK
| | - Peng Zhang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
- Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
| | - Jean-Baptiste Ladant
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Andrew P Roberts
- Research School of Earth Sciences, Australian National University, Canberra, Australia
| | - Alexis Licht
- Department of Earth and Space Sciences, University of Washington, Seattle, USA
| | - Qingsong Liu
- Centre for Marine Magnetism (CM2), Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Zhonghui Liu
- Department of Earth Sciences, University of Hong Kong, Hong Kong, China
| | - Mark J Dekkers
- Paleomagnetic Laboratory 'Fort Hoofddijk', Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Helen K Coxall
- Department of Geological Sciences, Stockholm University, Stockholm, Sweden
| | - Zhangdong Jin
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
- CAS Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi'an, China
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - Chunju Huang
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Guoqiao Xiao
- State Key Laboratory of Biogeology and Environmental Geology, School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Christopher J Poulsen
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Natasha Barbolini
- Department of Ecosystem and Landscape Dynamics, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Niels Meijer
- Universität Potsdam, Institute of Geosciences, Potsdam, Germany
| | - Qiang Sun
- College of Geology and Environment, Xi'an University of Science and Technology, Xi'an, China
| | - Xiaoke Qiang
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Jiao Yao
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Zhisheng An
- State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
- CAS Center for Excellence in Quaternary Science and Global Change, Chinese Academy of Sciences, Xi'an, China.
- Interdisciplinary Research Center of Earth Science Frontier, Beijing Normal University, Beijing, China.
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Abstract
During the Eocene, high-latitude regions were much warmer than today and substantial polar ice sheets were lacking. Indeed, the initiation of significant polar ice sheets near the end of the Eocene has been closely linked to global cooling. Here, we examine the relationship between global temperatures and continental-scale polar ice sheets following the establishment of ice sheets on Antarctica ∼34 million years ago, using records of surface temperatures from around the world. We find that high-latitude temperatures were almost as warm after the initiation of Antarctic glaciation as before, challenging our basic understanding of how climate works, and of the development of climate and ice volume through time. Falling atmospheric CO2 levels led to cooling through the Eocene and the expansion of Antarctic ice sheets close to their modern size near the beginning of the Oligocene, a period of poorly documented climate. Here, we present a record of climate evolution across the entire Oligocene (33.9 to 23.0 Ma) based on TEX86 sea surface temperature (SST) estimates from southwestern Atlantic Deep Sea Drilling Project Site 516 (paleolatitude ∼36°S) and western equatorial Atlantic Ocean Drilling Project Site 929 (paleolatitude ∼0°), combined with a compilation of existing SST records and climate modeling. In this relatively low CO2 Oligocene world (∼300 to 700 ppm), warm climates similar to those of the late Eocene continued with only brief interruptions, while the Antarctic ice sheet waxed and waned. SSTs are spatially heterogenous, but generally support late Oligocene warming coincident with declining atmospheric CO2. This Oligocene warmth, especially at high latitudes, belies a simple relationship between climate and atmospheric CO2 and/or ocean gateways, and is only partially explained by current climate models. Although the dominant climate drivers of this enigmatic Oligocene world remain unclear, our results help fill a gap in understanding past Cenozoic climates and the way long-term climate sensitivity responded to varying background climate states.
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