Early Cretaceous to present latitude of the central proto-Tibetan Plateau: A paleomagnetic synthesis with implications for Cenozoic tectonics, paleogeography, and climate of Asia

Author(s):  
Peter C. Lippert ◽  
Douwe J.J. van Hinsbergen ◽  
Guillaume Dupont-Nivet
Lithos ◽  
2018 ◽  
Vol 318-319 ◽  
pp. 283-298 ◽  
Author(s):  
Jingyi Zhang ◽  
Touping Peng ◽  
Weiming Fan ◽  
Guochun Zhao ◽  
Xiaohan Dong ◽  
...  

Author(s):  
Yue Qi ◽  
Qiang Wang ◽  
Gang-jian Wei ◽  
Xiu-Zheng Zhang ◽  
Wei Dan ◽  
...  

Diverse rock types and contrasting geochemical compositions of post-collisional mafic rocks across the Tibetan Plateau indicate that the underlying enriched lithospheric mantle is heterogeneous; however, how these enriched mantle sources were formed is still debated. The accreted terranes within the Tibetan Plateau experienced multiple stages of evolution. To track the geochemical characteristics of their associated lithospheric mantle through time, we can use mantle-derived magmas to constrain the mechanism of mantle enrichment. We report zircon U-Pb ages, major and trace element contents, and Sr-Nd isotopic compositions for Early Cretaceous and late Eocene mafic rocks in the southern Qiangtang terrane. The Early Cretaceous Baishagang basalts (107.3 Ma) are characterized by low K2O/Na2O (<1.0) ratios, arc-like trace element patterns, and uniform Sr-Nd isotopic compositions [(87Sr/86Sr)i = 0.7067−0.7073, εNd(t) = −0.4 to −0.2]. We suggest that the Baishagang basalts were derived from partial melting of enriched lithospheric mantle that was metasomatized by subducted Bangong−Nujiang oceanic material. We establish the geochemistry of the pre-collisional enriched lithospheric mantle under the southern Qiangtang terrane by combining our data with those from other Early Cretaceous mafic rocks in the region. The late Eocene (ca. 35 Ma) post-collisional rocks in the southern Qiangtang terrane have low K2O/Na2O (<1.0) ratios, and their major element, trace element, and Sr-Nd isotopic compositions [(87Sr/86Sr)i = 0.7042−0.7072, εNd(t) = −4.5 to +1.5] are similar to those of the Early Cretaceous mafic rocks. Based on the distribution, melting depths, and whole-rock geochemical compositions of the Early Cretaceous and late Eocene mafic rocks, we argue that the primitive late Eocene post-collisional rocks were derived from pre-collisional enriched lithospheric mantle, and the evolved samples were produced by assimilation and fractional crystallization of primary basaltic magma. Asthenosphere upwelling in response to the removal of lithospheric mantle induced the partial melting of enriched lithospheric mantle at ca. 35 Ma.


2013 ◽  
Vol 87 (2) ◽  
pp. 289-303 ◽  
Author(s):  
WU Zhenhan ◽  
HU Daogong ◽  
YE Peisheng ◽  
WU Zhonghai

2020 ◽  
Vol 789 ◽  
pp. 228500 ◽  
Author(s):  
Yong Cao ◽  
Zhiming Sun ◽  
Haibing Li ◽  
Xiaozhou Ye ◽  
Jiawei Pan ◽  
...  

Author(s):  
Ye Wang ◽  
Xuanhua Chen ◽  
Yaoyao Zhang ◽  
Zheng Yin ◽  
Andrew V. Zuza ◽  
...  

Although the Cenozoic Indo-Asian collision is largely responsible for the formation of the Tibetan plateau, the role of pre-Cenozoic structures in controlling the timing and development of Cenozoic deformation remains poorly understood. In this study we address this problem by conducting an integrated investigation in the northern foreland of the Tibetan plateau, north of the Qilian Shan-Nan Shan thrust belt, NW China. The work involves field mapping, U-Pb detrital-zircon dating of Cretaceous strata in the northern foreland of the Tibetan plateau, examination of growth-strata relationships, and construction and restoration of balanced cross sections. Our field mapping reveals multiple phases of deformation in the area since the Early Cretaceous, which was expressed by northwest-trending folding and northwest-striking thrusting that occurred in the early stages of the Early Cretaceous. The compressional event was followed immediately by extension and kinematically linked right-slip faulting in the later stage of the Early Cretaceous. The area underwent gentle northwest-trending folding since the late Miocene. We estimate the magnitude of the Early Cretaceous crustal shortening to be ∼35%, which we interpret to have resulted from a far-field response to the collision between the Lhasa and the Qiangtang terranes in the south. We suggest that the subsequent extension in the Early Cretaceous was induced by orogenic collapse. U-Pb dating of detrital zircons, sourced from Lower Cretaceous sedimentary clasts from the north and the south, implies that the current foreland region of the Tibetan plateau was a topographic depression between two highland regions in the Early Cretaceous. Our work also shows that the Miocene strata in the foreland region of the northern Tibetan plateau was dominantly sourced from the north, which implies that the rise of the Qilian Shan did not impact the sediment dispersal in the current foreland region of the Tibetan plateau where this study was conducted.


Author(s):  
Xu Han ◽  
Jin-Gen Dai ◽  
Jie Lin ◽  
Shi-Ying Xu ◽  
Bo-Rong Liu ◽  
...  

Reconstruction of Cretaceous geological evolution of Tibetan Plateau growth is critical for assessing the effect of India-Asia collision on the formation of its high elevation. However, Cretaceous topographic evolution and geodynamic mechanism in northern Lhasa remain ambiguous. Here we present results from sedimentology, zircon U-Pb ages, and detrital Cr-spinel composition of the Tangza Formation in the western part of northern Lhasa. Sedimentary lithofacies document that orbitolinid foraminifera−limestone beds were deposited in a shallow-marine setting, while clastic rocks accumulated in an alluvial fan during the middle Cretaceous. Zircon U-Pb ages of interbedded volcanic rocks place a robust constraint on the initiation of clastic rock deposition at ca. 106 Ma. Sandstones are enriched lithic fragments with abundant volcanic grains. U-Pb ages of detrital zircon display a prominent age population at 101−130 Ma with a 120 Ma peak. These data indicate that the clastic rocks were mainly derived from northern Lhasa, including an Early Cretaceous magmatic arc. Sedimentary and provenance characteristics are most consistent with deposition in a local foreland basin. The activation of south-vergent local thrusting may be responsible for loading of the Tangza foreland basin. This thrust faulting may be associated with crustal shortening induced by the continuous convergence of Lhasa and Qiangtang since collision initiated during the Early Cretaceous. The initial uplift of western and central parts of northern Lhasa and eastern Gangdese arc occurred at ca. 106 Ma, while the widespread uplift of northern and central Lhasa probably initiated at ca. 92 Ma. The mid−Late Cretaceous uplift in Lhasa was significantly earlier than the early Cenozoic India-Asia collision.


1978 ◽  
Vol 83 (B11) ◽  
pp. 5377 ◽  
Author(s):  
James Ni ◽  
James E. York

Sign in / Sign up

Export Citation Format

Share Document