Eccentricity-paced monsoon variability on the northeastern Tibetan Plateau in the Late Oligocene high CO2 world

Hong Ao; Diederik Liebrand; Mark J Dekkers; Peng Zhang; Yougui Song; Qingsong Liu; Tara N Jonell; Qiang Sun; Xinzhou Li; Xinxia Li; Xiaoke Qiang; Zhisheng An

doi:10.1126/sciadv.abk2318

Eccentricity-paced monsoon variability on the northeastern Tibetan Plateau in the Late Oligocene high CO₂ world

Sci Adv. 2021 Dec 17;7(51):eabk2318. doi: 10.1126/sciadv.abk2318. Epub 2021 Dec 15.

Authors

Hong Ao^{1

2}, Diederik Liebrand^{3

4}, Mark J Dekkers⁵, Peng Zhang^{1

2}, Yougui Song^{1

2}, Qingsong Liu⁶, Tara N Jonell⁷, Qiang Sun⁸, Xinzhou Li^{1

2}, Xinxia Li⁹, Xiaoke Qiang¹, Zhisheng An^{1

2}

Affiliations

¹ State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
² Open Studio for Oceanic-Continental Climate and Environment Changes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China.
³ National Oceanography Centre, European Way, SO14 3ZH Southampton, UK.
⁴ PalaeoClimate.Science, 27 Granby Grove, SO17 3RY, Southampton, UK.
⁵ Paleomagnetic Laboratory Fort Hoofddijk, Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands.
⁶ Centre for Marine Magnetism (CM2), Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
⁷ School of Geographical and Earth Sciences, University of Glasgow, Glasgow, UK.
⁸ College of Geology and Environment, Xi'an University of Science and Technology, Xi'an, China.
⁹ School of Earth Sciences, China University of Geosciences (Wuhan), Wuhan, China.

Abstract

Constraining monsoon variability and dynamics in the warm unipolar icehouse world of the Late Oligocene can provide important clues to future climate responses to global warming. Here, we present a ~4-thousand year (ka) resolution rubidium-to-strontium ratio and magnetic susceptibility records between 28.1 and 24.1 million years ago from a distal alluvial sedimentary sequence in the Lanzhou Basin (China) on the northeastern Tibetan Plateau margin. These Asian monsoon precipitation records exhibit prominent short (~110-ka) and long (405-ka) eccentricity cycles throughout the Late Oligocene, with a weak expression of obliquity (41-ka) and precession (19-ka and 23-ka) cycles. We conclude that a combination of eccentricity-modulated low-latitude summer insolation and glacial-interglacial Antarctic Ice Sheet fluctuations drove the eccentricity-paced precipitation variability on the northeastern Tibetan Plateau in the Late Oligocene high CO₂ world by governing regional temperatures, water vapor loading in the western Pacific and Indian Oceans, and the Asian monsoon intensity and displacement.