Late Cretaceous tectono-magmatic activity in the Nize region, central Tibet: evidence for lithospheric delamination beneath the Qiangtang–Lhasa collision zone

Abstract. Stratigraphy, detailed structural mapping and a crustal-scale cross section across the NW Zagros collision zone provide constraints on the spatial evolution of oblique convergence of the Arabian and Eurasian plates since the Late Cretaceous. The Zagros collision zone in NW Iran consists of the internal Sanandaj–Sirjan, Gaveh Rud and Ophiolite zones and the external Bisotoun, Radiolarite and High Zagros zones. The Main Zagros Thrust is the major structure of the Zagros suture zone. Two stages of oblique deformation are recognized in the external part of the NW Zagros in Iran. In the early stage, coexisting dextral strike-slip and reverse dominated domains in the Radiolarite zone developed in response to deformation partitioning due to oblique convergence. Dextral-reverse faults in the Bisotoun zone are also compatible with oblique convergence. In the late stage, deformation partitioning occurred during southeastward propagation of the Zagros orogeny towards its foreland resulting in synchronous development of orogen-parallel strike-slip and thrust faults. It is proposed that the first stage was related to Late Cretaceous oblique obduction, while the second stage resulted from Cenozoic collision. The Cenozoic orogen-parallel strike-slip component of Zagros oblique convergence is not confined to the Zagros suture zone (Main Recent Fault) but also occurred in the external part (Marekhil–Ravansar fault system). Thus, it is proposed that oblique convergence of Arabian and Eurasian plates in Zagros collision zone initiated with oblique obduction in the Late Cretaceous followed by oblique collision in the late Tertiary, consistent with global plate reconstructions.

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Closure of the Bangong–Nujiang Tethyan Ocean in the central Tibet: Results from the provenance of the Duoni Formation

Journal of Sedimentary Research ◽

10.2110/jsr.2019.55 ◽

2019 ◽

Vol 89 (10) ◽

pp. 1039-1054 ◽

Cited By ~ 5

Author(s):

Zhicai Zhu ◽

Qingguo Zhai ◽

Peiyuan Hu ◽

Sunlin Chung ◽

Yue Tang ◽

...

Keyword(s):

Early Cretaceous ◽

Late Cretaceous ◽

Suture Zone ◽

The Tibetan Plateau ◽

Tectonic History ◽

Magmatic Rocks ◽

Two Samples ◽

Delta Sequence ◽

History Of ◽

Central Tibet

ABSTRACT The closure of the Bangong–Nujiang Tethyan Ocean (BNTO) and consequent Lhasa–Qiangtang collision is vital to reasonably understanding the early tectonic history of the Tibetan Plateau before the India-Eurasia collision. The timing of the Lhasa–Qiangtang collision was mainly constrained by the ophiolite and magmatic rocks in previous studies, with only limited constraints from the sedimentary rocks within and adjacent to the Bangong–Nujiang suture zone. In the middle segment of the Bangong–Nujiang suture zone, the Duoni Formation, consisting of a fluvial delta sequence with minor andesite interlayers, was originally defined as the Late Cretaceous Jingzhushan Formation and interpreted as the products of the Lhasa–Qiangtang collision during the Late Cretaceous. Our new zircon U-Pb data from two samples of andesite interlayers demonstrate that it was deposited during the latest Early Cretaceous (ca. 113 Ma) rather than Late Cretaceous. Systemic studies on the sandstone detrital model, heavy-mineral assemblage, and clasts of conglomerate demonstrate a mixed source of both Lhasa and Qiangtang terranes and ophiolite complex. Clasts of conglomerate contain abundant angular peridotite, gabbro, basalt, chert, andesite, and granite, and minor quartzite and gneiss clasts also exist. Sandstones of the Duoni Formation are dominated by feldspathic–lithic graywacke (Qt25F14L61 and Qm13F14L73), indicative of a mixture of continental-arc and recycled-orogen source origin. Detrital minerals of chromite, clinopyroxene, epidote, and hornblende in sandstone also indicate an origin of ultramafic and mafic rocks, while garnets indicate a metamorphosed source. Paleocurrent data demonstrate bidirectional (southward and northward) source origins. Thus, we suggest that the deposition of the Duoni Formation took place in the processes of the Lhasa–Qiangtang collision during the latest Early Cretaceous (∼ 113 Ma), and the BNTO had been closed by this time.

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Petrogenesis and tectonic implications of Late Cretaceous highly fractionated I-type granites from the Qiangtang block, central Tibet

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2019.02.022 ◽

2019 ◽

Vol 176 ◽

pp. 337-352 ◽

Cited By ~ 7

Author(s):

Haiyang He ◽

Yalin Li ◽

Chengshan Wang ◽

Zhongpeng Han ◽

Pengfei Ma ◽

...

Keyword(s):

Late Cretaceous ◽

Tectonic Implications ◽

Central Tibet

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The role of crustal models in the dynamics of the India–Eurasia collision zone

Geophysical Journal International ◽

10.1093/gji/ggaa299 ◽

2020 ◽

Vol 223 (1) ◽

pp. 111-131

Author(s):

Srishti Singh ◽

Attreyee Ghosh

Keyword(s):

Mantle Convection ◽

Hybrid Models ◽

P Wave ◽

Gravitational Potential Energy ◽

Coupled Models ◽

Moment Tensors ◽

Collision Zone ◽

Central Tibet ◽

Deviatoric Stresses ◽

Surface Observations

SUMMARY We investigate how different crustal models can affect the stress field, velocities and associated deformation in the India–Eurasia collision zone. We calculate deviatoric stresses, which act as deformation indicators, from topographic load distribution and crustal heterogeneities coupled with density driven mantle convection constrained by tomography models. We use three different crustal models, CRUST2.0, CRUST1.0 and LITHO1.0 and observe that these models have different crustal thickness and densities. As a result, gravitational potential energy (GPE) calculated based on these densities and crustal thicknesses differ between these models and so do the associated deviatoric stresses. For GPE only models, LITHO1.0 provides a better constraint on deformation as it yields the least misfit (both orientation and relative magnitude) with the surface observations of strain rates, lithospheric stress, plate motions and earthquake moment tensors. However, when the stresses from GPE are added to those associated with mantle tractions arising from density-driven mantle convection, the coupled models in all cases provide a better fit to surface observations. The N–S tensional stresses predicted by CRUST2.0 in this area get reduced significantly due to addition of large N–S compressional stresses predicted by the tomography models S40RTS and SAW642AN leading to an overall strike-slip regime. On the other hand, the hybrid models, SINGH_S40RTS and SINGH_SAW that are obtained by embedding a regional P-wave model, Singh et al., in global models of S40RTS and SAW642AN, predict much lower compression within this area. These hybrid models provide a better constraint on surface observations when coupled with CRUST1.0 in central Tibet, whereas the combined LITHO1.0 plus mantle traction model provides a better fit in some other areas, but with a degradation of fit in central Tibet.

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Late Cretaceous K-rich magmatism in central Tibet: Evidence for early elevation of the Tibetan plateau?

Lithos ◽

10.1016/j.lithos.2012.11.019 ◽

2013 ◽

Vol 160-161 ◽

pp. 1-13 ◽

Cited By ~ 70

Author(s):

Yalin Li ◽

Juan He ◽

Chengshan Wang ◽

M. Santosh ◽

Jingen Dai ◽

...

Keyword(s):

Tibetan Plateau ◽

Late Cretaceous ◽

The Tibetan Plateau ◽

Central Tibet ◽

Early Elevation

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Origin of the ca. 90Ma magnesia-rich volcanic rocks in SE Nyima, central Tibet: Products of lithospheric delamination beneath the Lhasa-Qiangtang collision zone

Lithos ◽

10.1016/j.lithos.2014.03.019 ◽

2014 ◽

Vol 198-199 ◽

pp. 24-37 ◽

Cited By ~ 73

Author(s):

Qing Wang ◽

Di-Cheng Zhu ◽

Zhi-Dan Zhao ◽

Sheng-Ao Liu ◽

Sun-Lin Chung ◽

...

Keyword(s):

Volcanic Rocks ◽

Collision Zone ◽

Central Tibet

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India-Asia collision paleogeography constrained by Burma Terrane (Myanmar) Late Cretaceous to Miocene paleomagnetic data

10.5194/egusphere-egu2020-1523 ◽

2020 ◽

Author(s):

Jan Westerweel ◽

Pierrick Roperch ◽

Alexis Licht ◽

Guillaume Dupont-Nivet ◽

Zaw Win ◽

...

Keyword(s):

Late Cretaceous ◽

Late Eocene ◽

Plate Tectonic ◽

Himalayan Orogen ◽

Collision Zone ◽

Tectonic Reconstruction ◽

Order Constraints ◽

Climatic Evolution ◽

Tectonic Reconstructions ◽

Eastern Edge

<p>The paleogeographic evolution of the India-Asia collision and the resulting formation of the Himalayan orogen remain an intensely debated topic. A variety of disputed models propose different collision ages for the numerous terranes incorporated into the collision with variable paleolatitudes and tectonic rotations that can be constrained using paleomagnetism. Recent plate tectonic reconstructions have shown that the Burma Terrane (BT), a microplate at the eastern edge of the Himalayan orogen, is a key element to solve the India-Asia collision puzzle. Here we provide new paleomagnetic and geochronological data of Paleocene, Eocene, Oligocene and Miocene age, in addition to our previously published Late Cretaceous and late Eocene results. We present a robust plate tectonic reconstruction for the BT with GPlates software, and show that the BT moved towards southern hemisphere latitudes between the Late Cretaceous and Paleocene without significant rotation. Starting in the Paleocene, the BT and India coevally moved northwards and the BT started to undergo a major clockwise rotation of ~60 &#778;. By the late Eocene, most of this rotation was completed and the BT was translated ~2000 km northward from near-equatorial latitudes without significant rotation. This northward translation culminated with the early Miocene indentation of the BT into the eastern Himalayan collision zone, leading to the setup of the modern Eastern Himalayan Syntaxis. These first order constraints are used to infer a Trans-Tethyan arc collision model including timing of rollback, extrusion and initiation of strike-slip systems. Our model has important implications for Asian biotic and climatic evolution.</p>

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