| Autor: |
Tianyang Wang, Songlin He, Lin Ding, Qinghai Zhang, Fulong Cai, Chao Wang, Jing Xie, Guobiao Li, Jiani Sheng, Zhenyu Li, Xuesong Ma, Yahui Yue |
| Rok vydání: |
2022 |
| DOI: |
10.21203/rs.3.rs-1755905/v1 |
| Popis: |
Globally elevated temperatures during the Cretaceous extreme greenhouse climate interval were punctuated by the Valanginian Weissert event, which was characterised by a positive carbon isotope excursion, global cooling, and a glacial event approximately at 135 Ma. The inability to disentangle ocean temperature and continental ice volume trends hinders our understanding of these climate fluctuations in deep-time. We investigated the ocean temperature–ice sheet dynamics of glaciation events that occurred in the Cretaceous greenhouse world. New clumped isotope and δ18O data from sits in the Tethyan Ocean show that seawater temperatures decreased by 5°C–6°C, consistent with the development of glacial periods, and maximum ice volumes about half the size of present-day Antarctica. This cooling event provides a counter-example to other Mesozoic climate transitions driven by changes in atmospheric greenhouse gas contents. Our results suggest a robust coupling between mid-latitude seawater temperatures and polar ice volume as atmospheric CO2 contents decline. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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