Northern Lhasa thrust belt of central Tibet: Evidence of Cretaceous–early Cenozoic shortening within a passive roof thrust system?

2014 ◽  
Author(s):  
John E. Volkmer ◽  
Paul Kapp ◽  
Brian K. Horton ◽  
George E. Gehrels ◽  
Joseph M. Minervini ◽  
...  
Keyword(s):  
Thrust Belt ◽  
Thrust System ◽  
Central Tibet ◽  
Early Cenozoic

Structural Deformation of Southern Tien Shan Fold-Thrust Belt — Take the North Margin of Kashi for Example

2014 ◽  
Vol 1010-1012 ◽  
pp. 1419-1424
Author(s):  
Jun Feng Qian
Keyword(s):  
Large Scale ◽  
Deep Structure ◽  
Seismic Profile ◽  
Tien Shan ◽  
Structural Deformation ◽  
Thrust Belt ◽  
The North ◽  
Thrust System ◽  
Shortening Rate ◽  
Detachment Surface

The Structural and deformational features of fold-thrust belt in the north margin of Kashi，southern Tian Shan were disclosed based on various data such as two dimensional seismic profile and field geologic survey. The results show that the fold-thrustbelt can be divided into several rows of anticlines, includingKalaboketuoer-Wenguer, Tuopa-Kangxiweier, Atushi and Kashi on plane,and the development of Atushi anticlines and its north side was controlled by the activity of the thrust system originated along the middle Cambrian Awatage Group from north to south. The fold-thrust belt can be divided into two different spatial levels: the shallow tectonic is a large scale imbricate thrust system, the detachment surface is uplifted from Cambrian system to Neogene system; the deep structure is a buried duplex structure system, the fault in floor and fault in roof are located at gypsic horizon in Cambrian and Neogene systemrespectively. Based on structural deformation analyzing and balanced section technology, the distribution of each anticlinal belt and the structure style of the low and deep thrust systems are confirmed. In this area the distance is shortened by 32.64～49.1km from north to south since Pliocene with the scalage of 40.5%～50.51%，and its average crustal shortening rate is 9.11～13.71mm/a.

Amber fossils reveal the Early Cenozoic dipterocarp rainforest in central Tibet

Palaeoworld ◽  
2018 ◽  
Vol 27 (4) ◽  
pp. 506-513 ◽  
Author(s):  
He Wang ◽  
Suryendu Dutta ◽  
Richard S. Kelly ◽  
Arka Rudra ◽  
Sha Li ◽  
...  
Keyword(s):  
Central Tibet ◽  
Early Cenozoic

Structural and kinematic analyses of the basement window within the hinterland fold-and-thrust belt of the Zagros orogen, Iran

2016 ◽  
Vol 154 (5) ◽  
pp. 983-1000 ◽  
Author(s):  
KHALIL SARKARINEJAD ◽  
SOMAYE DERIKVAND
Keyword(s):  
Pure Shear ◽  
Thrust Belt ◽  
Lattice Preferred Orientation ◽  
Fold And Thrust Belt ◽  
Instantaneous Strain ◽  
Oblique Convergence ◽  
Kinematic Analyses ◽  
Strain Axis ◽  
Thrust System ◽  
Zagros Orogen

AbstractThe Zagros hinterland fold-and-thrust belt is located in the central portion of the Zagros Thrust System and consists of the exhumed basement windows associated with NW-striking and NE-dipping flexural duplex structures that contain in-sequence thrusting and related folds. Mylonitic nappes of the basement were exhumed along deep-seated sole thrusts of the Zagros Thrust System. Lattice preferred orientation (LPO) c-axes of quartz show asymmetric type-1 crossed girdles that demonstrate a non-coaxial deformation under plane strain conditions. Based on the opening angles of quartz c-axis fabric skeletons, deformation temperatures vary from 425±50°C to 540±50°C, indicating amphibolite facies conditions. The estimated mean kinematic vorticity evaluated from quartz c-axis of the quartzo-feldspathic mylonites (Wm = 0.55±0.06) indicates the degree of non-coaxiality during mylonite exhumation. The estimated angle θ between the maximum instantaneous strain axis (ISA1) and the transpressional zone boundary is 17°, and the angle of oblique convergence is 57° in the M2 nappe of the basement involved. This indicates that the mylonitic nappe was formed by a combination of 62% pure shear and 38% simple shear during oblique convergence.

The Berit transect of the Tauride thrust belt, S Turkey: Late Cretaceous–Early Cenozoic accretionary/collisional processes related to closure of the Southern Neotethys

2006 ◽  
Vol 27 (1) ◽  
pp. 108-145 ◽  
Author(s):  
Alastair H.F. Robertson ◽  
Timur Ustaömer ◽  
Osman Parlak ◽  
Ulvi Can Ünlügenç ◽  
Kemal Taşlı ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Thrust Belt ◽  
Early Cenozoic

Cenozoic thrust system, basin evolution, and uplift of the Tanggula Range in the Tuotuohe region, central Tibet

2012 ◽  
Vol 22 (2) ◽  
pp. 482-492 ◽  
Author(s):  
Yalin Li ◽  
Chengshan Wang ◽  
Xixi Zhao ◽  
An Yin ◽  
Chao Ma
Keyword(s):  
Basin Evolution ◽  
Thrust System ◽  
Central Tibet

scholarly journals Thrusting, exhumation, and basin fill on the western margin of the South China block during the India-Asia collision

2020 ◽  
Vol 133 (1-2) ◽  
pp. 74-90 ◽  
Author(s):  
Kai Cao ◽  
Philippe Hervé Leloup ◽  
Guocan Wang ◽  
Wei Liu ◽  
Gweltaz Mahéo ◽  
...  
Keyword(s):  
Structural Analysis ◽  
South China ◽  
Hanging Wall ◽  
Crustal Thickening ◽  
South China Block ◽  
Thrust Belt ◽  
Western Margin ◽  
Crustal Shortening ◽  
Fold And Thrust Belt ◽  
Early Cenozoic

Abstract The pattern and timing of deformation in southeast Tibet resulting from the early stages of the India-Asia collision are crucial factors to understand the growth of the Tibetan Plateau, but they remain poorly constrained. Detailed field mapping, structural analysis, and geochronological and thermochronological data along a 120 km section of the Ludian-Zhonghejiang fold-and-thrust belt bounding the Jianchuan basin in western Yunnan, China, document the early Cenozoic tectonic evolution of the conjunction between the Lanping-Simao and South China blocks. The study area is cut by two major southwest-dipping brittle faults, named the Ludian-Zhonghejiang fault and the Tongdian fault from east to west. Numerous kinematic indicators and the juxtaposition of Triassic metasedimentary rocks on top of Paleocene strata indicate thrusting along the Ludian-Zhonghejiang fault. Similarly, structural analysis shows that the Tongdian fault is a reverse fault. Between these structures, fault-bounded Permian–Triassic and Paleocene rocks are strongly deformed by nearly vertical and upright southwest-vergent folds with axes that trend nearly parallel to the traces of the main faults. Zircon and apatite (U-Th)/He and apatite fission-track data from a Triassic pluton with zircon U-Pb ages of 237–225 Ma in the hanging wall of the Ludian-Zhonghejiang fault, assisted by inverse modeling, reveal two episodes of accelerated cooling during 125–110 Ma and 50–39 Ma. The Cretaceous cooling event was probably related to crustal thickening during the collision between the Lhasa and Qiangtang terranes. The accelerated exhumation during 50–39 Ma is interpreted to record the life span of the fold-and-thrust belt. This timing is corroborated by the intrusive relationship of Eocene magmas of ca. 36–35 Ma zircon U-Pb age into the fold-and-thrust belt. Early Cenozoic activity of the deformation system controlled deposition of alluvial-fan and braided-river sediments in the Jianchuan basin, as evidenced by eastward and northeastward paleoflows and terrestrial clasts derived from the hanging wall of the Ludian-Zhonghejiang thrust. Since 39 Ma, decreasing cooling rates likely reflect cessation of activity on the fold-and-thrust belt. Early Cenozoic compressive deformation on the western margin of the South China block together with geological records of contraction in central, northern, and eastern Tibet document Eocene upper-crustal shortening located in the Himalaya, Qiangtang terrane, and northern plateau margins together with contractional basin development in the intervening Lhasa, Songpan-Garze, and Kunlun terranes, coeval with or shortly after the onset of the India-Asia collision. This suggests that moderate crustal shortening affected a large part of Tibet in a spaced way, contrary to models of homogeneous crustal thickening soon after the collision, and prior to the main crustal thickening, propagating progressively from south to north. This complex deformation pattern illustrates the complexity of Asian crustal rheology, which contrasts with assumptions in existing geodynamic models.

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