| Autor: |
Junling Pei, Ahmed Mansour, Gaojie Li, Haisheng Yi, Xin Jin, Chihua Wu, Zhiqiang Shi, Guoqing Xia, Qiushuang Fan, Juan Pedro Rodríguez-López |
| Rok vydání: |
2021 |
| Předmět: |
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| DOI: |
10.21203/rs.3.rs-835656/v1 |
| Popis: |
There is no agreement regarding the processes that have governed the birth and vanish of ice masses on Earth during Cenozoic, as well as the possible existence of unipolar vs bipolar glaciations which remain controversial. Although it is generally accepted that Cenozoic cryosphere was characterized by a unipolar Antarctic glaciation at the Eocene-Oligocene Transition (~ 34 Ma), recent investigations suggest synchronous cryospheric processes at both hemispheres at this time. Here we present the first worldwide evidence of ice-related structures in Eocene-Oligocene sediments from the mid-latitude Lunpola Basin of central Tibet. The lacustrine deposits contain two intervals dated 37.8–35.6 and 34.0-32.5 Ma, respectively, which preserve seasonal frost events, glendonites and ice-rafted debris. These cryospheric processes were synchronous with two recorded stratigraphic intervals containing ice-rafted debris along offshore Greenland and in the Arctic region. Our results provide robust continental evidence of Eocene-Oligocene bipolar glaciation and a direct evidence for an already uplifted central Tibet during late Eocene. This finding brings into debate the timing and magnitude of inherited elevation of the vast proto-Tibetan Plateau before the continental collision between India and Eurasia. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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