Two-phase intracontinental deformation mode in the context of India-Eurasia collision: Insights from a structural analysis of the West Kunlun-southern Junggar transect along the NW margin of the Tibetan Plateau

2021 ◽  
pp. jgs2021-029
Author(s):  
Hanlin Chen ◽  
Xiubin Lin ◽  
Xiaogan Cheng ◽  
Junfeng Gong ◽  
Shuang Bian ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Deformation Mode ◽  
The Tibetan Plateau ◽  
The West ◽  
Two Phase ◽  
Phase Deformation ◽  
Thrust Belts ◽  
Fold And Thrust Belts ◽  
West Kunlun ◽  
Weak Zones

The India-Eurasia convergence since early Cenozoic has established the Tibetan Plateau and the Circum-Tibetan Plateau Basin and Orogen System (CTPBOS). When and how the convergence-driving strain has propagated into the CTPBOS is of significant importance in deciphering the growth process of the Tibetan Plateau. In this study, we conduct a structural analysis of the West Kunlun-southern Junggar transect along the NW margin of the Tibetan Plateau to establish the deformation propagation and through this to determine the plateau growth processes. The results suggest a two-phase deformation mode. The first stage features deformation confined in pre-existing weak zones like the West Kunlun orogen, Buchu Uplift and Tian Shan orogen during Paleogene, in which the intracontinental strain was speculated to be mainly consumed by shortening of these weak zones. The second stage is characterized by deformation propagating into foreland regions since early Miocene, in which shorting along foreland fold-and-thrust belts of a scale of tens of kilometers and decreasing basinwardly plays a key role in absorbing intracontinental strain. We suggest that this two-phase deformation mode possibly reflects a shift of governing mechanism of the expansion of the Tibetan Plateau from a rigid-block manner to a critical wedge taper style.Thematic collection: This article is part of the Fold-and-thrust belts collection available at: https://www.lyellcollection.org/cc/fold-and-thrust-belts

Multi-stage exhumation history of the West Kunlun orogen and the amalgamation of the Tibetan Plateau

2019 ◽  
Vol 528 ◽  
pp. 115833 ◽  
Author(s):  
Guangwei Li ◽  
Mike Sandiford ◽  
Aimin Fang ◽  
Barry Kohn ◽  
Dan Sandiford ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
The West ◽  
Multi Stage ◽  
History Of ◽  
West Kunlun ◽  
Exhumation History

scholarly journals Energy and mass balance characteristics of the Guliya ice cap in the West Kunlun Mountains, Tibetan Plateau

2019 ◽  
Vol 159 ◽  
pp. 71-85 ◽  
Author(s):  
Shenghai Li ◽  
Tandong Yao ◽  
Wusheng Yu ◽  
Wei Yang ◽  
Meilin Zhu
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
The West ◽  
Ice Cap ◽  
Kunlun Mountains ◽  
West Kunlun

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 A global climatology of stratosphere–troposphere exchange using the ERA-Interim data set from 1979 to 2011

2014 ◽  
Vol 14 (2) ◽  
pp. 913-937 ◽  
Author(s):  
B. Škerlak ◽  
M. Sprenger ◽  
H. Wernli
Keyword(s):  
North America ◽  
Tibetan Plateau ◽  
Mass Flux ◽  
West Coast ◽  
Surface Ozone ◽  
Control Surface ◽  
The Tibetan Plateau ◽  
The West ◽  
Data Set ◽  
Ozone Flux

Abstract. In this study we use the ERA-Interim reanalysis data set from the European Centre for Medium-Range Weather Forecasts (ECMWF) and a refined version of a previously developed Lagrangian methodology to compile a global 33 yr climatology of stratosphere–troposphere exchange (STE) from 1979 to 2011. Fluxes of mass and ozone are calculated across the tropopause, pressure surfaces in the troposphere, and the top of the planetary boundary layer (PBL). This climatology provides a state-of-the-art quantification of the geographical distribution of STE and the preferred transport pathways, as well as insight into the temporal evolution of STE during the last 33 yr. We confirm the distinct zonal and seasonal asymmetry found in previous studies using comparable methods. The subset of "deep STE", where stratospheric air reaches the PBL within 4 days or vice versa, shows especially strong geographical and seasonal variations. The global hotspots for deep STE are found along the west coast of North America and over the Tibetan Plateau, especially in boreal winter and spring. An analysis of the time series reveals significant positive trends of the net downward mass flux and of deep STE in both directions, which are particularly large over North America. The downward ozone flux across the tropopause is dominated by the seasonal cycle of ozone concentrations at the tropopause and peaks in summer, when the mass flux is nearly at its minimum. For the subset of deep STE events, the situation is reversed and the downward ozone flux into the PBL is dominated by the mass flux and peaks in early spring. Thus surface ozone concentration along the west coast of North America and around the Tibetan Plateau are likely to be influenced by deep stratospheric intrusions. We discuss the sensitivity of our results on the choice of the control surface representing the tropopause, the horizontal and vertical resolution of the trajectory starting grid, and the minimum residence time τ used to filter out transient STE trajectories.

scholarly journals Integrated Geophysical Evidence for the Middle-Lower Crust Melting of the Songpan-Aba Terrain, NE Tibetan Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Chongjin Zhao ◽  
Luolei Zhang ◽  
Peng Yu ◽  
Xi Xu
Keyword(s):  
Tibetan Plateau ◽  
Magnetic Layer ◽  
Orogenic Belt ◽  
The Tibetan Plateau ◽  
The West ◽  
Magnetotelluric Data ◽  
West Qinling ◽  
The North ◽  
Weakly Magnetic ◽  
Surrounding Areas

The Songpan−Aba region is located on the northeastern edge of the Tibetan Plateau. Tectonically, the area is surrounded by the West Qinling orogenic belt in the north, the Longmenshan orogenic belt in the southeast, and the East Kunlun and Sanjiang orogenic belts in the west and southwest, forming a triangle that provides an ideal location to study the crust-mantle structure and deep tectonics of the eastward extrusion of the Tibetan Plateau. In this study, the magnetic and electrical structures of the Songpan−Aba area were investigated by inversion using high-precision magnetic anomaly and magnetotelluric data to obtain the subsurface magnetization inversion intensity and resistivity of Songpan–Aba and adjacent areas. The results revealed a continuous magnetic layer up to 20 km below Songpan–Aba and its surrounding areas in the south, possibly originating from a magma root southwest of the Longmenshan massif. In the West Qinling, Songpan–Aba, and Longmenshan areas, pervasive low-resistance, weakly magnetic, or magnetic layers were identified below 20 km that might be formed from the molten mantle material extruded from the eastern edge of the Tibetan Plateau.

scholarly journals Rapid Eocene Exhumation of the West Qinling Belt: Implications for the Growth of the Northeastern Tibetan Plateau

Lithosphere ◽  
2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Yi-Peng Zhang ◽  
Wen-Jun Zheng ◽  
Wei-Tao Wang ◽  
Yun-Tao Tian ◽  
Renjie Zhou ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Hanging Wall ◽  
The Tibetan Plateau ◽  
Collision System ◽  
The West ◽  
Crustal Shortening ◽  
Late Mesozoic ◽  
West Qinling ◽  
Northeastern Tibetan Plateau ◽  
Thermal Histories

Abstract Cenozoic exhumation in the northeastern Tibetan Plateau provides insights into spatial-temporal patterns of crustal shortening, erosion, landscape evolution, and geodynamic drivers in the broad India-Eurasia collision system. The NW-SE trending West Qinling Belt has been a central debate as to when crustal shortening took place. Within the West Qinling Belt, a thick succession of Cretaceous sedimentary rocks has been deformed and exhumed along major basin-bounding thrust faults. We present new apatite (U-Th)/He ages from the hanging wall and footwall of this major thrust. Contrasting thermal histories show that rapid cooling commenced as early as ca. 45 Ma and continued for 15–20 Myr for the hanging wall, whereas the footwall experiences continuous cooling and slow exhumation since the late Mesozoic. We infer that accelerated exhumation was driven by thrusting in response to the northward growth of the Tibetan Plateau during the Eocene (ca. 45–35 Ma) based on regional sedimentological, structural, and thermochronological data.

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