The role of pre-existing weak zones in the formation of the Himalaya and Tibetan plateau: 3-D thermomechanical modelling

2020 ◽  
Vol 221 (3) ◽  
pp. 1971-1983
Author(s):  
Lin Chen ◽  
Lijun Liu ◽  
Fabio A Capitanio ◽  
Taras V Gerya ◽  
Yang Li
Keyword(s):  
Tibetan Plateau ◽  
Early Stage ◽  
Crustal Thickening ◽  
The Tibetan Plateau ◽  
Crustal Material ◽  
Weak Zone ◽  
Orogenic Wedge ◽  
Orogenic Plateau ◽  
Weak Zones

SUMMARY The Tibetan crust is sliced by several east–west trending suture zones. The role of these suture zones in the evolution of the Himalayan range and Tibetan plateau remains unclear. Here we use 3-D thermomechanical simulations to investigate the role of pre-existing weak zones within the Asian Plate in the formation of orogen and plateau growth during continental collision. Our results show that partitioning of deformation along the convergent margin leads to scraping off of crustal material into an orogenic wedge above the margin and crustal thickening in the retro-continent, eventually forming a large orogenic plateau in front of the indenter. Pre-existing weak zone(s) within the retro-continent is reactivated at the early stage of convergence, and facilitates the northward propagation of strain and widening of the orogenic plateau. The northernmost weak zone sets the northern limit of the Tibetan plateau. Our models also show rheological weakening of the congested buoyant crust within the collisional zone drives wedge-type exhumation of deeply buried crust at the southern flank of the plateau, which may explain the formation of the Greater Himalayan Sequence.

scholarly journals The role of ASM on the formation and properties of cirrus clouds over the Tibetan Plateau

Tellus B ◽  
2019 ◽  
Vol 71 (1) ◽  
pp. 1577070 ◽  
Author(s):  
Qianshan He ◽  
Xiangdong Zheng ◽  
Jian Li ◽  
Wei Gao ◽  
Yanyu Wang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Cirrus Clouds ◽  
The Tibetan Plateau

Role of Tibetan Women in Carbon Balance in the Alpine Grasslands of the Tibetan Plateau. A Review

2016 ◽  
Vol 20 (1) ◽  
pp. 108-122 ◽  
Author(s):  
Zhanhuan Shang ◽  
Andrew White ◽  
A. Allan Degen ◽  
Ruijun Long
Keyword(s):  
Tibetan Plateau ◽  
Carbon Balance ◽  
The Tibetan Plateau ◽  
Alpine Grasslands

Quantification of the relative role of land-surface processes and large-scale forcing in dynamic downscaling over the Tibetan Plateau

2016 ◽  
Vol 48 (5-6) ◽  
pp. 1705-1721 ◽  
Author(s):  
Yanhong Gao ◽  
Linhong Xiao ◽  
Deliang Chen ◽  
Fei Chen ◽  
Jianwei Xu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Land Surface ◽  
Large Scale ◽  
Surface Processes ◽  
The Tibetan Plateau ◽  
Relative Role ◽  
Dynamic Downscaling ◽  
Land Surface Processes

Remote Sources of Surface Temperature Cold Bias over the Tibetan Plateau: Role of Tropical SST Climatological Bias

2020 ◽  
Author(s):  
Yuting Wu ◽  
Xiaoming Hu ◽  
Ziqian Wang ◽  
Zhenning Li ◽  
Song Yang
Keyword(s):  
Tibetan Plateau ◽  
Surface Temperature ◽  
Distribution Pattern ◽  
Climate Models ◽  
Cmip5 Models ◽  
Cold Bias ◽  
The Tibetan Plateau ◽  
Sst Bias ◽  
Hypothesis Model

<p>The surface temperature cold bias over the Tibetan Plateau (TP) is a long-lasting problem in both reanalysis data and climate models. While previous studies have mainly focused on local processes for this bias, the TP surface temperature is also closely related to tropical SST in both observations and Coupled Model Inter-comparison Project (CMIP5) models. This study investigates the role of tropical SST climatological bias in the TP surface temperature cold bias, and analysis of CMIP5 models suggests that the surface temperature cold bias over the TP is more obvious (about 4 K) in winter, with an east-west distribution pattern, than in summer (about 1 K), with a south-north distribution pattern. Considering that the tropical SST bias in CMIP5 models may be an important source of the TP surface temperature cold bias, a series of model experiments were conducted by the NCAR CAM4 to test the hypothesis. Model experiment results show that the tropical SST bias can reproduce cold bias over the TP, with 2 K in winter and about 0.5 K in summer. The mechanisms for TP surface temperature cold bias are different in winter and summer. In winter, tropical SST bias influences the TP surface temperature mainly by anomalous snow cover, while anomalous precipitation and clouds are more important for the temperature bias in summer.</p>

scholarly journals The role of island-arc oceanic, collisional and intraplate magmatism in the formation of continental crust in the Mongolia-Trasnbaikalia region: geostructural, geochronological and Sm-Nd isotope data

2021 ◽  
Vol 12 (1) ◽  
pp. 1-47
Author(s):  
I. V. Gordienko
Keyword(s):  
Continental Crust ◽  
Early Stage ◽  
Island Arc ◽  
Published Data ◽  
Crustal Material ◽  
Tectonic Structures ◽  
Nd Isotope ◽  
Isotope Data ◽  
Intraplate Magmatism

The formation of continental crust in the Mongolia-Transbaikalia region is researched to identify the mechanisms of interactions between the crust and the mantle in the development of the Neoarchean, Proterozoic and Paleozoic magmatic and sedimentary complexes in the study area. Using the results of his own studies conducted for many years and other published data on this vast region of Central Asia, the author have analysed compositions, ages and conditions for the formation of Karelian, Baikalian, Caledonian and Hercynian structure-formational complexes in a variety of geodynamic settings. Based on the geostructural, petrological, geochemical, geochronological and Sm-Nd isotope data, he determines the crustal and mantle sources of magmatism, conducts the identification and mapping of isotopic provinces, and reveals the role of island-arc oceanic, accretion-collision and intraplate magmatism in the formation of continental crust. Considering the formation of the bulk continental crust, three main stages are distinguished: (1) Neoarchean and Paleoproterozoic (Karelian) (almost 30% of the crust volume), (2) Meso-Neoproterozoic (Baikalian) (50%), and (3) Paleozoic (Caledonian and Hercynian) (over 20%). This sequence of the evolution stages shows the predominance of the ancient crustal material in igneous rocks sources at the early stage. During the subsequent stages, tectonic structures created earlier were repeatedly reworked, and mixed crustal-mantle and juvenile sources were widely involved in the formation of the bulk continental crust in the study area.

Incision migration across Eastern Tibet controlled by monsoonal climate, not tectonics?

2020 ◽  
Author(s):  
Katharine Groves ◽  
Mark Allen ◽  
Christopher Saville ◽  
Martin Hurst ◽  
Stuart Jones
Keyword(s):  
Tibetan Plateau ◽  
Transition Zone ◽  
Channel Flow ◽  
East Asian Monsoon ◽  
Crustal Thickening ◽  
Mean Annual Precipitation ◽  
The Tibetan Plateau ◽  
Geomorphic Indices ◽  
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. Geomorphic indices capture the landscape response to competition between climate and tectonics and reflect the spatial distribution of erosion. We analyse the link between climate and tectonics in the eastern part of the Tibetan Plateau using the mean annual precipitation, digital elevation data, and by calculating the geomorphic indices hypsometric integral (HI), surface roughness (SR) and elevation relief ratio (ZR). 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”).</p><p>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. A broad transition zone is present in the landscape, where changes in landscape and precipitation are grouped and in alignment. The zone cuts across structural boundaries. It represents, from East to West, a sharp decline in precipitation below ~650 mm/yr (interpreted as the western extent of the East Asian monsoon), a change from a high relief landscape to smoother elevations at 4500-5000 m, a transition to low HI (< 0.05), a decrease in SR and an increase in ZR. This zone is not a drainage divide: the main rivers have their headwaters further West, in the interior of the plateau.</p><p>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. Published low temperature thermochronology data suggest the plateau had reached its modern extent at the Eocene, but has been exhumed since ~15 Ma to the East of the transition zone, at least along major drainage networks. We therefore also suggest that the transition zone is the current position of a long-term wave of incision that has migrated from East to West, driven by late Cenozoic intensification of the monsoon climate. This work supports a model of early Cenozoic growth of the eastern Tibetan Plateau, superimposed by incision driven by climate change; it does not support the channel flow model.</p>

Palaeomagnetic constraints on Himalayan-Tibetan tectonic evolution

1988 ◽  
Vol 326 (1589) ◽  
pp. 177-188 ◽  
Keyword(s):  
Tibetan Plateau ◽  
South China ◽  
Large Scale ◽  
Indian Subcontinent ◽  
Eastern China ◽  
Crustal Thickening ◽  
The Tibetan Plateau ◽  
South China Block ◽  
The South ◽  
Palaeomagnetic Data

Palaeomagnetic data from the Lhasa, Qiangtang and Kunlun Terranes of the Tibetan Plateau are used with data from stable Eurasia, eastern China and Indochina, to test different models of crustal thickening in the Tibetan Plateau, to attempt a Carboniferous palaeogeographic reconstruction, and to calculate the relative motion between the South China Block and the Indochina Block. The data suggest that since the onset of the India—Eurasia collision, the Lhasa Terrane has moved 2000 + 800 km north with respect to stable Eurasia. This indicates that strong internal defomation must have taken place in southern Eurasia since the collision, and thus challenges the model of large-scale underthrusting of the Indian subcontinent beneath the Tibetan Plateau as the mechanism for crustal thickening in Tibet. Palaeomagnetic results from the Kunlun Terrane show that it was at 22° south latitude during the Carboniferous. A Carboniferous reconstruction is presented in which the Kunlun and Qiangtang Terranes, several Indochina terranes, and the North and South China Blocks are grouped together. These units of continental crust all share the specific tropical and subtropical Cathaysian flora, and the group is therefore called the Cathaysian composite continent. To test the model of propagating extrusion tectonics, we have used newly available palaeomagnetic results from South China and Indochina to calculate probable displacements. This exercise suggests a rotation of about 8° of Indochina with respect to the South China Block that is smaller than the predicted rotation of 40°, A large eastward translation of the South China Block relative to the Indochina Block of about 1500 km is consistent with the palaeomagnetic data.

Sign in / Sign up

Export Citation Format

Share Document