New field and geophysical data about transpressional deformation: An improved model for the structural style of Sha Gou fault area in southern Ningxia, northeastern edge of Tibetan Plateau, China

2015 ◽  
Vol 112 ◽  
pp. 25-41 ◽  
Author(s):  
Lu Xia ◽  
Zhen Liu ◽  
Haihua Zhao ◽  
Jun Wang ◽  
Peng Xiang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Geophysical Data ◽  
Structural Style ◽  
Improved Model ◽  
Southern Ningxia

scholarly journals India Indenting Eurasia: A Brief Review and New Data from the Yongping Basin on the SE Tibetan Plateau

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 518
Author(s):  
Tiannan Yang ◽  
Zhen Yan ◽  
Chuandong Xue ◽  
Di Xin ◽  
Mengmeng Dong
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
Geophysical Data ◽  
Oblique Collision ◽  
Second Stage ◽  
Three Stages ◽  
Se Tibet ◽  
Two Stages ◽  
Seismic Anomalies ◽  
Comprehensive Compilation

Successive indentations of Eurasia by India have led to the Tibet-Himalaya E–W orthogonal collision belt and the SE Tibetan Plateau N–S oblique collision belt along the frontal and eastern edges of the indenter, respectively. The belts exhibit distinctive lithospheric structures and tectonic evolutions. A comprehensive compilation of available geological and geophysical data reveals two sudden tectonic transitions in the early Eocene and the earliest Miocene, respectively, of the tectonic evolution of the orthogonal belt. Synthesizing geological and geochronological data helps us to suggest a NEE–SWW trending, ~450 km-long, ~250 km-wide magmatic zone in SE Tibet, which separates the oblique collision belt (eastern and SE Tibet) into three segments of distinctive seismic structures including the mantle and crust anisotropies. The newly identified Yongping basin is located in the central part of the magmatic zone. Geochronological and thermochronological data demonstrate that (1) this basin and the magmatic zone started to form at ~48 Ma likely due to NNW–SSE lithosphere stretching according to the spatial coincidence of the concentrated mantle-sourced igneous rocks on the surface with the seismic anomalies at depth; and (2) its fills was shortened in the E–W direction since ~23 Ma. These two dates correspond to the onset of the first and second tectonic transitions of the orthogonal collision belt. As such, both the orthogonal and oblique belts share a single time framework of their tectonic evolution. By synthesizing geological and geophysical data of both collision belts, the indenting process can be divided into three stages separated by two tectonic transitions. Continent–continent collision as a piston took place exclusively during the second stage. During the other two stages, the India lithosphere underthrust beneath Eurasia.

Reconciling plate convergence and orogeny: The influence of India-Asia convergence rate on the formation of the Himalayas

2020 ◽  
Author(s):  
Ben S. Knight ◽  
Fabio A. Capitanio ◽  
Roberto F. Weinberg
Keyword(s):  
Tibetan Plateau ◽  
Numerical Models ◽  
The Tibetan Plateau ◽  
Thrust Belt ◽  
Plate Convergence ◽  
Structural Style ◽  
Fold And Thrust Belt ◽  
Velocity History ◽  
The Himalaya

<p>The collision of India and Eurasia since ~50 Ma has resulted in a broad range of deformation along the Himalaya-Tibetan orogeny, accommodating >2700 km of convergence. The region is characterised by the Tibetan Plateau, the Himalayan internal units and fold-and-thrust belt from North to South. These formed as a consequence of a convergence history characterised by a progressive decrease in velocity, from ~10 cm/yr 50 Ma, to ~8 cm/yr 42.5 Ma and to present-day values of ~4 cm/yr around 20 Ma. Here, we test the controls of such a convergence velocity history on the orogeny of a viscoplastic wedge during collision, above a subducting continental lithosphere. We compare numerical models simulating India-Asia plate convergence and collision, comparing the structures observed throughout the evolution with those observed in the Himalayan-Tibetan region. The models display distinct phases of growth and structural style evolution in the Himalayan-Tibetan region that are a result of the change in convergence velocity and long-term collision. After an initial stacking, the high convergence velocity forces deformation migration towards the upper plate, where a plateau forms, while late stage slowdown of collision favours the formation of the Himalayan fold-and-thrust belt. While the latter is in agreement with the structuring of the southermost domains and the South Tibetan Detachment (STD) fault, the former provide constraints to the initial uplift of the Tibetan Plateau.</p>

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