Stress transfer along the western boundary of the Bayan Har Block on the Tibet Plateau from the 2008 to 2020 Yutian earthquake sequence in China

<p>In recent decades, plateau margins have attracted attention because the understanding of their dynamics and history provides insights into the modes of crustal deformation responsible for the plateau structure and morphology and more widely into the deformation of continental lithosphere. The slip transformation and strain partitioning mechanism at the eastern termination of the Kunlun fault system remain unclear. Geophysics investigations revealed the Ruoergai Basin as a rigid block; however, insufficient information is available on the role of this block in tectonic transformation zone at east Tibet. We employed the finite element method in our simulations to delimitate the presence of the Ruoergai block and determine how it affects the surrounding area. We found that the Ruoergai block moves independently to the east or northeast, and its motion differs from that of the Bayan Har block in the eastward escape process of this last-named block. The formation and behavior of Awancang fault and Longriba fault seems to impact by the Ruoergai block. The influence of the Ruoergai block in the east margin should not be ignored. The Awancang fault and Ruoergai block absorbed the north vector velocity of the Bayan Har block, after which the Bayan Har block started moving southeast. The strain partitioning at the eastern margin of the Tibet Plateau is progressively complete[A1] &#160;from the Awancang fault, Ruoergai block, and Longriba fault area to the Longmenshan block. The presence of the Ruoergai block could decrease the strike-slip rate of the Maqin&#8211;Maqu section of the Kunlun fault. Given its influence in the region, the Ruoergai block should be incorporated in future studies on regional deformation and in deformation and tectonic transformation models. Then we compared the deformation and tectonic transformation models in the northern margin of the Tibet Plateau. Proposed a rigid block compression pattern unite the tectonic transformation and deformation issue, further explain most of the fault behaviors in the northern margin and eastern margin of Tibet.</p><p>&#160;</p>

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Extension of the Upper Yellow River into the Tibet Plateau: Review and New Data

Quaternary ◽

10.3390/quat4020014 ◽

2021 ◽

Vol 4 (2) ◽

pp. 14

Author(s):

Zhengchen Li ◽

Xianyan Wang ◽

Jef Vandenberghe ◽

Huayu Lu

Keyword(s):

Tibetan Plateau ◽

Yellow River ◽

Google Earth ◽

Tibet Plateau ◽

The Yellow River ◽

Published Data ◽

The Tibetan Plateau ◽

Large Lakes ◽

River Terraces ◽

The Tibet Plateau

The Wufo Basin at the margin of the northeastern Tibet Plateau connects the upstream reaches of the Yellow River with the lowland catchment downstream, and the fluvial terrace sequence in this basin provides crucial clues to understand the evolution history of the Yellow River drainage system in relation to the uplift and outgrowth of the Tibetan Plateau. Using field survey and analysis of Digital Elevation Model/Google Earth imagery, we found at least eight Yellow River terraces in this area. The overlying loess of the highest terrace was dated at 1.2 Ma based on paleomagnetic stratigraphy (two normal and two reversal polarities) and the loess-paleosol sequence (12 loess-paleosol cycles). This terrace shows the connections of drainage parts in and outside the Tibetan Plateau through its NE margin. In addition, we review the previously published data on the Yellow River terraces and ancient large lakes in the basins. Based on our new data and previous researches, we conclude that the modern Yellow River, with headwaters in the Tibet Plateau and debouching in the Bohai Sea, should date from at least 1.2 Ma. Ancient large lakes (such as the Hetao and Sanmen Lakes) developed as exorheic systems and flowed through the modern Yellow River at that time.

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