Paleomagnetism and U-Pb Geochronology of Early Cretaceous Volcanic Rocks from the Qiangtang Block, Tibetan Plateau: Implications for the Qiangtang-Lhasa Collision

2020 ◽  
Vol 789 ◽  
pp. 228500 ◽  
Author(s):  
Yong Cao ◽  
Zhiming Sun ◽  
Haibing Li ◽  
Xiaozhou Ye ◽  
Jiawei Pan ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Early Cretaceous ◽  
Volcanic Rocks

The middle Cretaceous (110−94 Ma) evolution of Tangza Basin in the western Tibetan Plateau and implications for initial topographic growth of northern Lhasa

2020 ◽  
Author(s):  
Xu Han ◽  
Jin-Gen Dai ◽  
Jie Lin ◽  
Shi-Ying Xu ◽  
Bo-Rong Liu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Early Cretaceous ◽  
Volcanic Rocks ◽  
Foreland Basin ◽  
High Elevation ◽  
Alluvial Fan ◽  
Magmatic Arc ◽  
Clastic Rocks ◽  
Western Tibetan Plateau ◽  
Spinel Composition

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.

Early Cretaceous volcanic rocks in Yunzhug area, central Tibet, China, associated with arc–continent collision in the Tibetan Plateau?

Lithos ◽  
2020 ◽  
pp. 105827
Author(s):  
Sheng-Sheng Chen ◽  
Wei-Ming Fan ◽  
Ren-Deng Shi ◽  
Ji-Feng Xu ◽  
Ke Yang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Early Cretaceous ◽  
Volcanic Rocks ◽  
The Tibetan Plateau ◽  
Central Tibet

Early Cretaceous crust–mantle interaction linked to rollback of the Palaeo-Pacific flat-subducting slab: constraints from the intermediate–felsic volcanic rocks of the northern Great Xing’an Range, NE China

2021 ◽  
pp. 1-22
Author(s):  
Jia-Hao Jing ◽  
Hao Yang ◽  
Wen-Chun Ge ◽  
Yu Dong ◽  
Zheng Ji ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Volcanic Rocks ◽  
Geochemical Data ◽  
Calc Alkaline ◽  
Ne China ◽  
Asthenospheric Mantle ◽  
High K ◽  
Wide Range ◽  
Great Xing’An Range ◽  
Subducting Slab

Abstract Late Mesozoic igneous rocks are important for deciphering the Mesozoic tectonic setting of NE China. In this paper, we present whole-rock geochemical data, zircon U–Pb ages and Lu–Hf isotope data for Early Cretaceous volcanic rocks from the Tulihe area of the northern Great Xing’an Range (GXR), with the aim of evaluating the petrogenesis and genetic relationships of these rocks, inferring crust–mantle interactions and better constraining extension-related geodynamic processes in the GXR. Zircon U–Pb ages indicate that the rhyolites and trachytic volcanic rocks formed during late Early Cretaceous time (c. 130–126 Ma). Geochemically, the highly fractionated I-type rhyolites exhibit high-K calc-alkaline, metaluminous to weakly peraluminous characteristics. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) but depleted in high-field-strength elements (HFSEs), with their magmatic zircons ϵHf(t) values ranging from +4.1 to +9.0. These features suggest that the rhyolites were derived from the partial melting of a dominantly juvenile, K-rich basaltic lower crust. The trachytic volcanic rocks are high-K calc-alkaline series and exhibit metaluminous characteristics. They have a wide range of zircon ϵHf(t) values (−17.8 to +12.9), indicating that these trachytic volcanic rocks originated from a dominantly lithospheric-mantle source with the involvement of asthenospheric mantle materials, and subsequently underwent extensive assimilation and fractional crystallization processes. Combining our results and the spatiotemporal migration of the late Early Cretaceous magmatic events, we propose that intense Early Cretaceous crust–mantle interaction took place within the northern GXR, and possibly the whole of NE China, and that it was related to the upwelling of asthenospheric mantle induced by rollback of the Palaeo-Pacific flat-subducting slab.

Early Cretaceous volcanic rocks and Early Cenozoic extrusions of Cape Mary, Schmidt Peninsula, north Sakhalin: Geochemical study

2007 ◽  
Vol 1 (3) ◽  
pp. 265-275 ◽  
Author(s):  
V. P. Simanenko ◽  
S. V. Rasskazov ◽  
T. A. Yasnygina ◽  
A. I. Malinovskii ◽  
A. A. Chashchin
Keyword(s):  
Early Cretaceous ◽  
Volcanic Rocks ◽  
Geochemical Study ◽  
Early Cenozoic

Three stages of arc migration in the Carboniferous-Triassic in northern Qiangtang, central Tibet, China: Ridge subduction and asynchronous slab rollback of the Jinsha Paleotethys

2021 ◽  
Author(s):  
Yin Liu ◽  
Wenjiao Xiao ◽  
Brian F. Windley ◽  
Kefa Zhou ◽  
Rongshe Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Volcanic Rocks ◽  
Late Triassic ◽  
Geochemical Data ◽  
The Tibetan Plateau ◽  
Ridge Subduction ◽  
Temporal Relationships ◽  
Slab Rollback ◽  
Geodynamic Processes ◽  
Central Tibet

Carboniferous-Triassic magmatism in northern Qiangtang, central Tibet, China, played a key role in the evolution of the Tibetan Plateau yet remains a subject of intense debate. New geochronological and geochemical data from adakitic, Nb-enriched, and normal arc magmatic rocks, integrated with results from previous studies, enable us to determine the Carboniferous-Triassic (312−205 Ma), arc-related, plutonic-volcanic rocks in northern Qiangtang. Spatial-temporal relationships reveal three periods of younging including southward (312−252 Ma), rapid northward (249−237 Ma), and normal northward (234−205 Ma) migrations that correspond to distinct slab geodynamic processes including continentward slab shallowing, rapid trenchward slab rollback, and normal trenchward rollback of the Jinsha Paleotethys rather than the Longmuco-Shuanghu Paleotethys, respectively. Moreover, varying degrees of coexistence of adakites/High-Mg andesites (HMAs)/Nb-enriched basalt-andesites (NEBs) and intraplate basalts in the above-mentioned stages is consistent with the magmatic effects of slab window triggered by ridge subduction, which probably started since the Late Carboniferous and continued into the Late Triassic. The Carboniferous-Triassic multiple magmatic migrations and ridge-subduction scenarios provide new insight into the geodynamic processes of the Jinsha Paleotethys and the growth mechanism of the Tibetan Plateau.

scholarly journals Origin of Boron and Brine Evolution in Saline Springs in the Nangqen Basin, Southern Tibetan Plateau

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ji-long Han ◽  
Feng-qing Han ◽  
Syed-Asim Hussain ◽  
Wen-yu Liu ◽  
Xiu-qing Nian ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Volcanic Rocks ◽  
The Tibetan Plateau ◽  
Molar Ratios ◽  
Marine Carbonate ◽  
O Isotopes ◽  
Saline Springs ◽  
Crustal Origin ◽  
D Values ◽  
Saline Spring

The Nangqen Basin is a typical shearing-extensional basin situated in the hinterland of the Tibetan Plateau. It contains abundant saline spring resources and abnormal trace element enrichments. The hydrochemical molar ratios (Na/Cl, B/Cl, and Br/Cl), H-O isotopes, and B isotopes of the saline spring were systematically measured to describe the evolution of brines and the origin of the boron. The sodium chloride coefficient of the water samples in this area is around 1.0 or slightly greater, which is characteristic of leached brines; the highest B/Cl value is 4.25 (greater than that of seawater). The Na/Cl, B/Cl, and Br/Cl values of the springs are clear indicators of a crustal origin. Theδ18O values of the spring waters range from −12.88‰to −16.05‰, and theδD values range from −100.91‰to −132.98‰. Meanwhile the B content and B isotopes in the saline springs are in the ranges of 1.00 to 575.56 ppm and +3.55‰to +29.59‰, respectively. It has been proven that the saline springs in the Nangqen Basin are a type of leached brine, suggesting that the saline springs have a terrestrial origin. Theδ11B-B characteristics of the springs are similar to those observed in the Tibetan geothermal area, indicating that these two places have the same B source. Moreover, they have a crustal origin (marine carbonate rocks and volcanic rocks) instead of a deep mantle source.

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