Reevaluation of Coseismic Surface Ruptures Produced by the 1850 M 7.5 Xichang Earthquake on the Southeastern Margin of the Tibetan Plateau and Implications for Rupture Propagation at Bends on Strike‐Slip Faults

2018 ◽  
Vol 108 (1) ◽  
pp. 101-115 ◽  
Author(s):  
Hu Wang ◽  
Mingjian Liang ◽  
Shuaipo Gao ◽  
Yongkang Ran ◽  
Lichun Chen
Keyword(s):  
Tibetan Plateau ◽  
Strike Slip ◽  
The Tibetan Plateau ◽  
Rupture Propagation ◽  
Southeastern Margin ◽  
Surface Ruptures

scholarly journals Evolution of the Yangtze River network, southeastern Tibet: Insights from thermochronology and sedimentology

Lithosphere ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 3-18
Author(s):  
Loraine Gourbet ◽  
Rong Yang ◽  
Maria Giuditta Fellin ◽  
Jean-Louis Paquette ◽  
Sean D. Willett ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Yangtze River ◽  
Middle Miocene ◽  
Strike Slip ◽  
The Tibetan Plateau ◽  
Fluvial Incision ◽  
Upper Yangtze River ◽  
Southeastern Margin ◽  
The Upper Yangtze River ◽  
Southeastern Tibet

Abstract We performed apatite and zircon (U-Th)/He dating on a granitic pluton that has been offset by ∼10 km by motion on the sinistral strike-slip Xiangcheng fault in SW Sichuan, SE Tibetan plateau, where the Shuoqu River incises a deep valley before joining the upper Yangtze River. Mean ZHe cooling ages range from 49.5 ± 2.2 Ma to 68.6 ± 6.0 Ma. Samples located above 3870 m yield mean apatite (U-Th)/He ages ranging from 30.6 ± 1.4 Ma to 40.6 ± 2.7 Ma, whereas samples at lower elevations range from 9.8 ± 1.3 Ma to 14.6 ± 2.7 Ma. In the same region, Cenozoic continental sediments are exposed on the flanks of deep valleys. They consist of unsorted conglomerates and sandstones that partly fill a paleotopography. The sediments were deposited during an episode of rapid sedimentation, followed by incision that varies between 0.5 and 1.2 km. Thermal and exhumational modeling of the granite thermochronometric data indicates rapid cooling during the middle Miocene that was likely related to fluvial incision. Our findings suggest that the upper Yangtze River and its tributary (Shuoqu) were connected by the middle Miocene. Our modeling also supports the idea that the exhumation pattern during the Cenozoic in the southeastern margin of the Tibetan Plateau is spatially and temporally heterogeneous.

Extending the paleoglaciological record of the southeastern Tibetan Plateau by combining geochronological and high-resolution remote sensing techniques

2020 ◽  
Author(s):  
Arjen P. Stroeven ◽  
Ramona A.A. Schneider ◽  
Robin Blomdin ◽  
Natacha Gribenski ◽  
Marc W. Caffee ◽  
...  
Keyword(s):  
High Resolution ◽  
Tibetan Plateau ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Luminescence Dating ◽  
The Tibetan Plateau ◽  
Exposure Dating ◽  
Southeastern Margin ◽  
Downstream Communities

<p>Paleoglaciological data is a crucial source of information towards insightful paleoclimate reconstructions by providing vital boundary conditions for regional and global climate models. In this context, the Third Pole Environment is considered a key region because it is highly sensitive to global climate change and its many glaciers constitute a diminishing but critical supply of freshwater to downstream communities in SE Asia. Despite its importance, extents of past glaciation on the Tibetan Plateau remain poorly documented or controversial largely because of the lack of well define glacial chronostratigraphies and reconstructions of former glacier extent. This study contributes to a better documentation of the extent and improved resolution of the timing of past glaciations on the southeastern margin of the Tibetan Plateau. We deploy a high-resolution TanDEM-X Digital Elevation Model (12 m resolution) to produce maps of glacial and proglacial fluvial landforms in unprecedented detail. Geomorphological and sedimentological field observations complement the mapping while cosmogenic nuclide exposure dating of quartz samples from boulders on end moraines detail the timing of local glacier expansion. Additionally, samples for optically stimulated luminescence dating were taken from extensive and distinct terraces located in pull-apart basins downstream of the end moraines to determine their formation time. We compare this new dataset with new and published electron spin resonance ages from terraces. Temporal coherence between the different chronometers strengthens the geochronological record while divergence highlights limitations in the applicability of the chronometers to glacial research or in our conceptual understanding of landscape changes in tectonic regions. Results highlight our current understanding of paleoglaciation, landscape development, and paleoclimate on the SE Tibetan Plateau.</p>

Sign in / Sign up

Export Citation Format

Share Document