Quantifying the contribution of upper‐middle crustal shortening and lower crustal thickening to surface uplift in the south‐eastern Tibetan Plateau

2021 ◽  
Author(s):  
Chaoyang Li ◽  
Xiaodian Jiang ◽  
Wei Gong
Keyword(s):  
Tibetan Plateau ◽  
Crustal Thickening ◽  
Eastern Tibetan Plateau ◽  
The South ◽  
Crustal Shortening ◽  
South Eastern ◽  
Surface Uplift ◽  
Lower Crustal

scholarly journals Fire, vegetation and Holocene climate in the south-eastern Tibetan Plateau: a multi-biomarker reconstruction from Paru Co

2018 ◽  
Author(s):  
Alice Callegaro ◽  
Felipe Matsubara Pereira ◽  
Dario Battistel ◽  
Natalie M. Kehrwald ◽  
Broxton W. Bird ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Biomass Burning ◽  
Fire History ◽  
Vegetation Changes ◽  
The Tibetan Plateau ◽  
Eastern Tibetan Plateau ◽  
The South ◽  
South Eastern ◽  
The Past ◽  
High Concentrations

Abstract. The fire history of the Tibetan Plateau over centennial to millennial timescales is still unknown. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, provide continuous records of large-scale and local environmental modifications due to their accumulation of specific organic molecular markers throughout the past millennia. In order to reconstruct Holocene fire events and vegetation changes occurring on the south-eastern Tibetan Plateau and the surrounding areas, we improved and integrated previous analytical methods. The multi-proxy procedure was applied to samples retrieved from Paru Co, a small lake located in the Nyainqentanglha Mountains (29°47'45.6" N; 92°21'07.2" E; 4845 m a.s.l.). The investigated biomarkers include n-alkanes as indicators of vegetation, polycyclic aromatic hydrocarbons (PAHs) as combustion proxies, faecal sterols and stanols (FeSts) as indicators of the presence of humans or grazing animals and finally monosaccharide anhydrides (MAs) as specific markers of vegetation burning processes. Relatively high concentrations of both MAs and PAHs demonstrate intense local biomass burning activity during the early Holocene (10.9–10.7 cal ky BP), which correspond to a drier climate following deglaciation. High concentrations of MAs but not PAHs between 10.7–9 cal ky BP suggest a period of regional biomass burning followed by a decreasing fire trend through the mid-late Holocene. This fire history is consistent with local vegetation changes reconstructed from both n-alkanes and regional pollen records, where vegetation types depend on the centennial-scale intensity of monsoon precipitation. FeSts were below detection limits for most of the samples, suggesting limited direct human influences on fire regime and vegetation changes in the lake's catchment. Climate is the main influence on fire activity recorded in Paru Co over millennial timescales, where biomass burning fluctuates in response to alternating warm/humid and cool/dry periods.

Monsoon-driven incision and exhumation of the Eastern Tibetan Plateau

2021 ◽  
Author(s):  
Katharine Groves ◽  
Mark Allen ◽  
Christopher Saville ◽  
Martin Hurst ◽  
Stuart Jones
Keyword(s):  
Tibetan Plateau ◽  
Channel Flow ◽  
Crustal Thickening ◽  
Mean Annual Precipitation ◽  
The Tibetan Plateau ◽  
Eastern Tibetan Plateau ◽  
Geomorphic Indices ◽  
Surface Uplift ◽  
Hypsometric Integral ◽  
Early Cenozoic

<p>The formation and uplift history of the Tibetan Plateau, driven by the India-Eurasia collision, is the subject of intense research. We analyse the link between climate and tectonics in the central and eastern Tibetan Plateau using geomorphic indices of surface roughness (SR) hypsometric integral (HI) and elevation-relief ratio (ZR) and mean annual precipitation, thermochronology and erosion rate data. Geomorphic indices capture the landscape response to competition between climate and tectonics and reflect the spatial distribution of erosion. This is a region where competing tectonic models suggest either early Cenozoic plateau growth, or a late phase of crustal thickening, surface uplift and plateau growth driven by lower crustal flow (“channel flow”). Swath profiles of rainfall, elevation and the geomorphic indices were constructed, orthogonal to the internal drainage boundary. Each profile was analysed to find the location of maximum change in trend. We identify a broad ˜WSW-ENE trending transition in the landscape where changes in landscape and precipitation are grouped and in alignment. It represents, from east to west, a sharp decline in precipitation (interpreted as the western extent of the East Asian monsoon), a change to a low relief landscape at 4500-5000 m elevation, an increase in ZR and a transition to low HI and SR. This zone cuts across structural boundaries and is not a drainage divide: the main rivers have their headwaters further West, in the interior of the plateau. We argue that this geomorphic-climatic transition zone represents a change from incised to non-incised landscapes, the location of which is controlled by the western extent of the monsoon. Modern erosion rates are lower in the non-incised region, west of the monsoon extent (mean 0.02 mm/yr), than the incised region (mean 0.26 mm/yr). Compiled thermochronology data shows an increase in exhumation from ˜25 Ma in the incised area but no evidence of this increased exhumation in the non-incised area. This pattern supports a model of early Cenozoic growth of the eastern Tibetan Plateau, superimposed by incision driven by Miocene monsoon intensification. Our results do not support the channel flow model, which would predict an eastwards wave of surface uplift and therefore erosion and exhumation during the Miocene, which are not present in the data.</p>

scholarly journals Supplementary material to "Fire, vegetation and Holocene climate in the south-eastern Tibetan Plateau: a multi-biomarker reconstruction from Paru Co"

2018 ◽  
Author(s):  
Alice Callegaro ◽  
Felipe Matsubara Pereira ◽  
Dario Battistel ◽  
Natalie M. Kehrwald ◽  
Broxton W. Bird ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Eastern Tibetan Plateau ◽  
The South ◽  
Holocene Climate ◽  
South Eastern ◽  
Supplementary Material

scholarly journals Age dependence of xylogenesis and its climatic sensitivity in Smith fir on the south-eastern Tibetan Plateau

2012 ◽  
Vol 33 (1) ◽  
pp. 48-56 ◽  
Author(s):  
X. Li ◽  
E. Liang ◽  
J. Gricar ◽  
P. Prislan ◽  
S. Rossi ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Eastern Tibetan Plateau ◽  
Age Dependence ◽  
The South ◽  
South Eastern ◽  
Climatic Sensitivity
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