Life history of the plateau pika (Ochotona curzoniae) in alpine meadows of the Tibetan Plateau

AbstractThe Tibetan Plateau (TP) and surrounding regions have one of the most complex biotas on Earth. However, the evolutionary history of these regions in deep time is poorly understood. Here, we quantify the temporal changes in beta dissimilarities among zoogeographical regions during the Cenozoic using 4,966 extant terrestrial vertebrates and 1,278 extinct mammal genera. We identify ten present-day zoogeographical regions and find that they underwent a striking change over time. Specifically, the fauna on the TP was close to the Oriental realm in deep time but became more similar to the Palearctic realms more recently. The present-day zoogeographical regions generally emerged during the Miocene/Pliocene boundary (ca. 5 Ma). These results indicate that geological events such as the Indo-Asian Collision, the TP uplift, and the aridification of the Asian interior underpinned the evolutionary history of the zoogeographical regions surrounding the TP over different time periods.

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Late Cenozoic Denudation and Topographic Evolution History of the Lhasa River Drainage in Southern Tibetan Plateau: Insights From Inverse Thermal History Modeling

Frontiers in Earth Science ◽

10.3389/feart.2021.636459 ◽

2021 ◽

Vol 9 ◽

Author(s):

Dongxu Cai ◽

Xianyan Wang ◽

Guangwei Li ◽

Wenbin Zhu ◽

Huayu Lu

Keyword(s):

Tibetan Plateau ◽

Surface Erosion ◽

The Tibetan Plateau ◽

Monsoon Precipitation ◽

Late Cenozoic ◽

River Drainage ◽

History Of ◽

Southern Tibetan Plateau ◽

Lhasa River ◽

Topographic Evolution

The interaction of surface erosion (e.g., fluvial incision) and tectonic uplift shapes the landform in the Tibetan Plateau. The Lhasa River flows toward the southwest across the central Gangdese Mountains in the southern Tibetan Plateau, characterized by a low-relief and high-elevation landscape. However, the evolution of low-relief topography and the establishment of the Lhasa River remain highly under debate. Here, we collected thermochronological ages reported in the Lhasa River drainage, using a 3D thermokinematic model to invert both late Cenozoic denudation and relief history of the Lhasa River drainage. Our results show that the Lhasa River drainage underwent four-phase denudation history, including two-stage rapid denudation at ∼25–16 Ma (with a rate of ∼0.42 km/Ma) and ∼16–12 Ma (with a rate of ∼0.72 km/Ma). In the latest Oligocene–early Miocene, uplift of the Gangdese Mountains triggered the rapid denudation and the formation of the current main drainage of the Lhasa River. In the middle Miocene, the second stage of the rapid denudation and the high relief were associated with intense incision of the Lhasa River, which is probably due to the enhanced Asian summer monsoon precipitation. This later rapid episode was consistent with the records of regional main drainage systems. After ∼12 Ma, the denudation rate decreases rapidly, and the relief of topography in the central Gangdese region was gradually subdued. This indicates that the fluvial erosion resulting from Asian monsoon precipitation increase significantly impacts on the topographic evolution in the central Gangdese region.

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Paleoaltitudinal histories for the northern and southern margins of the Tibetan Plateau during the Late Cenozoic: revealed by GDGTs

10.5194/egusphere-egu21-14073 ◽

2021 ◽

Author(s):

Chihao Chen ◽

Yan Bai ◽

Xiaomin Fang ◽

Haichao Guo ◽

Weilin Zhang ◽

...

Keyword(s):

Tibetan Plateau ◽

Late Miocene ◽

Global Climate ◽

The Tibetan Plateau ◽

Lake Surface ◽

Terrestrial Organic Matter ◽

Plant Fossils ◽

History Of ◽

Monsoon System ◽

Uplift History

As an important driver of global climate change during the Cenozoic, the uplift of the Tibetan Plateau (TP) has strongly influenced the origination and evolution of the Asian monsoon system, and therefore the aridification of central Asia. Over the last two decades, the application of stable isotope paleoaltimeters and the discoveries of mammal and plant fossils have greatly promoted the understanding of the uplift history of the TP. However, paleoaltitudinal reconstructions based on different paleoaltimeters have suggested differing outcomes and therefore remain controversial. Novel paleoaltimeters have therefore needed to be developed and applied to constrain the uplift history of the TP more accurately and effectively by comparing and verifying multi-proxies. Paleothermometers based on glyceryl dialkyl glycerol tetraethers (GDGTs) are widely used in terrestrial and ocean temperature reconstructions. In this study, GDGT-based paleothermometers were tentatively applied to the Gyirong Basin on the southern TP, and the Xining Basins on the northern TP, in an attempt to quantitatively reconstruct their paleoaltitudes.Both soil and aquatic-typed branched GDGTs have been identified from Late Miocene to Mid-Pliocene (7.0-3.2 Ma) samples taken from the Gyirong Basin; their reconstructed paleotemperatures were 7.5&#177;3.3&#176;C and 14.2&#177;4.5&#176;C, respectively. The former temperature may represent the mean temperature of the terrestrial organic matter input area, while the latter may represent the lake surface temperature. The results would suggest that the lake surface of the Gyirong Basin during the Late Miocene to Mid-Pliocene was 2.5&#177;0.8 km and that the surrounding mountains exceeded 3.6&#177;0.6 km, implying that the central Himalayas underwent a rapid uplift of ~1.5 km after the Mid-Pliocene.GDGT-based paleotemperature reconstructions using MBT'5ME values show that the Xining Basin dropped in temperature by ~10&#176;C during the ~10.5-8 Ma period, exceeding that in sea surface temperatures and low-altitude terrestrial temperatures during these periods. By combining these results with contemporaneous tectonic and sedimentary records, we infer that these cooling events signaled the regional uplift with the amplitude of ~1 km of the Xining basins. Our results support that the TP was still growing and uplifting substantially since the Late Miocene, which may provide new evidence for understanding the growth, expansion and uplift patterns of the TP.

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