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Eocene-Oligocene glaciation on a high central Tibetan Plateau
journal contribution
posted on 2023-06-10, 06:45 authored by Guoqing Xia, Chihua Wu, Ahmed Mansour, Xin Jin, Haisheng Yi, Gaojie Li, Qiushuang Fan, Zhiqiang Shi, Julian MurtonJulian Murton, Junling Pei, Juan Pedro Rodriguez LopezJuan Pedro Rodriguez LopezThe nature of glaciation (bipolar vs. unipolar) during the Eocene-Oligocene transition (EOT) remains unresolved. Here, we report the occurrence of frost marks, ice-rafted debris (IRD), and glendonites from the Upper Eocene to Lower Oligocene Niubao Formation (Fm.) deposited in a proglacial lake above glaciolacustrine conglomerates and diamictite facies in the Lunpola Basin, central Tibetan Plateau (CTP). Magnetostratigraphy dates these cryospheric deposits to ca. 36.2-31.8 Ma, synchronous with a stratigraphic interval containing IRD offshore of SE Greenland and in the Barents, Chukchi, and Laptev Seas, suggesting a strong continental-oceanic coupling. Our results provide robust continental evidence for intermittent cryospheric processes in the midlatitude Northern Hemisphere during the late Eocene and EOT. The global cold snap EOT-1 influenced already glacierized high-altitude mountains, lowering equilibrium line altitudes (ELAs) of glaciers and leading to local development of ice fields, ice caps, and valley glaciers with proglacial lake systems, such as the one recorded in the Niubao Fm. The record of IRD, glendonites, and frost marks before the onset of EOT-1 points to an active cryosphere on a plateau already elevated by ca. 36.2 Ma.
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GeologyISSN
0091-7613Publisher
Geological Society of AmericaExternal DOI
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- Geography Publications
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- Yes
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- Yes
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2023-04-14First Open Access (FOA) Date
2023-04-14First Compliant Deposit (FCD) Date
2023-04-14Usage metrics
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