Late Triassic granitic magmatism in the Eastern Qiangtang, Eastern Tibetan Plateau: Geochronology, petrogenesis and implications for the tectonic evolution of the Paleo-Tethys

2015 ◽  
Vol 27 (4) ◽  
pp. 1494-1508 ◽  
Author(s):  
Touping Peng ◽  
Guochun Zhao ◽  
Weiming Fan ◽  
Bingxia Peng ◽  
Yongsheng Mao
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
Late Triassic ◽  
Eastern Tibetan Plateau ◽  
Granitic Magmatism

Source and pressure effects in the genesis of the Late Triassic high Sr/Y granites from the Songpan-Ganzi Fold Belt, eastern Tibetan Plateau

Lithos ◽  
2020 ◽  
Vol 368-369 ◽  
pp. 105584
Author(s):  
Qiong-Yao Zhan ◽  
Di-Cheng Zhu ◽  
Qing Wang ◽  
Roberto F. Weinberg ◽  
Jin-Cheng Xie ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Pressure Effects ◽  
Late Triassic ◽  
Eastern Tibetan Plateau ◽  
Fold Belt

Petrogenesis of Late Cretaceous I-type granites in the southern Yidun Terrane: New constraints on the Late Mesozoic tectonic evolution of the eastern Tibetan Plateau

Lithos ◽  
2014 ◽  
Vol 208-209 ◽  
pp. 202-219 ◽  
Author(s):  
Xin-Song Wang ◽  
Rui-Zhong Hu ◽  
Xian-Wu Bi ◽  
Cheng-Biao Leng ◽  
Li-Chuan Pan ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Cretaceous ◽  
Tectonic Evolution ◽  
Eastern Tibetan Plateau ◽  
Late Mesozoic

scholarly journals Multiple sources and magmatic evolution of the Late Triassic Daocheng batholith in the Yidun Terrane: Implications for evolution of the Paleo-Tethys Ocean in the eastern Tibetan Plateau

2021 ◽  
Author(s):  
Pengsheng Dong ◽  
Guochen Dong ◽  
M. Santosh ◽  
Xuanxue Mo ◽  
Peng Wang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Chemical Diffusion ◽  
Late Triassic ◽  
Eastern Tibetan Plateau ◽  
Multiple Sources ◽  
Nd Isotopes ◽  
Fine Grained ◽  
Tethys Ocean ◽  
T Values ◽  
Lower Crustal

Granitoids with diverse composition and tectonic settings provide important tools for exploring crustal evolution and regional geodynamic history. Here we present an integrated study using petrological, mineralogical, zircon U-Pb geochronological, whole-rock geochemical, and isotopic data on the Late Triassic Daocheng batholith in the Yidun Terrane with a view to understanding the petrogenesis of a compositionally diverse batholith and its implications for the evolution of the Paleo-Tethys Ocean in the eastern Tibetan Plateau. The different lithological units of the batholith, including granodiorite, monzogranite, and quartz diorite, with abundant mafic microgranular enclaves in the granodiorite (MME I) and monzogranite (MME II), show identical crystallization ages of 218−215 Ma. The mineral assemblage and chemical composition of the granodiorite are identical to those of tonalitic-granodioritic melts generated under water-unsaturated conditions. The insignificant Eu anomalies and low magmatic temperatures indicate hydrous melting in the source. The relatively narrow range of whole-rock chemical and Sr-Nd isotopes, as well as the zircon trace element and Hf isotopic compositions of the granodiorite, suggest a homogeneous crustal source for the magma. Our modeling suggests that the rock was produced by 20−50% of lower crustal melting. The Daocheng monzogranites display more evolved compositions and larger variations in Sr-Nd-Hf isotopes than the granodiorite, which are attributed to assimilation and the fractional crystallization process. This is evidenced by the presence of metasedimentary enclave and inherited zircon grains with Neoproterozoic and Paleozoic ages, a non-cotectic trend in composition, and the trend shown by the modeling of initial 87Sr/86Sr ratios and Sr. The quartz diorites and MMEs showing composition similar to that of andesitic primary magma have high zircon εHf(t) values and are characterized by enrichment in LILEs and depletion of HFSEs. They were derived from the partial melting of lithospheric mantle that had been metasomatized by slab melts and fluids. The MMEs in both rocks display typical igneous texture and higher rare earth element (REE) and incompatible element concentrations than their host granites. The presence of fine-grained margins, acicular apatite, and plagioclase megacrysts suggests a magma mingling process. The overgrowth of amphibole around the pyroxene, quartz ocelli rimmed by biotite, and oscillatory zones of plagioclase are all indicative of chemical diffusion. Their enriched Sr-Nd isotopes imply isotopic equilibrium with the host granites. Based on a comparison with the coeval subduction-related magmatism, we propose that subduction and subsequent rollback of the Paleo-Tethys (Garzê-Litang Ocean) oceanic slab was the possible mechanism that triggered the diverse Triassic magmatism within the eastern Tibetan Plateau.

Imaging the Late Triassic lithospheric architecture of the Yidun Terrane, eastern Tibetan Plateau: Observations and interpretations

2021 ◽  
Author(s):  
Qiong-Yao Zhan ◽  
Di-Cheng Zhu ◽  
Qing Wang ◽  
Peter A. Cawood ◽  
Jin-Cheng Xie ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Oceanic Lithosphere ◽  
Late Triassic ◽  
Eastern Tibetan Plateau ◽  
Magmatic Differentiation ◽  
Isotopic Compositions ◽  
Magmatic Rocks ◽  
Mantle Sources ◽  
Magma Sources ◽  
Nonlinear Trends

The present-day lithospheric architecture of modern and ancient orogens can be imaged by geophysical techniques. For ancient orogens, unravelling their architecture at the time of formation is hindered by later tectono-magmatic events. In this paper, we use spatial variations in radiogenic isotopic compositions of Late Triassic magmatism from the Yidun Terrane, eastern Tibetan Plateau, to establish its lithospheric architecture during the Triassic. Comprehensive geochemical and isotopic data of Late Triassic magmatic rocks from four transects across the Yidun Terrane document eastward enrichment in whole-rock Nd, Sr, and zircon Hf isotopic compositions. Mafic and felsic rocks of major plutons show coherent and nonlinear trends in the Zr and P2O5 systematics and have limited variation of isotopic compositions. This indicates that Late Triassic magmatic differentiation was dominated by fractionation of mantle-derived mafic magmas. The spatial isotopic trends result from changing mantle sources, including variable contributions of isotopically depleted asthenospheric mantle and isotopically enriched subcontinental lithospheric mantle (SCLM) to magma sources. The spatial variation of mantle sources suggests a westward thinning of the SCLM during the Triassic. We propose that this architecture is most likely associated with eastward subduction of oceanic lithosphere of the Jinshajiang Ocean located at the west of the Yidun Terrane, immediately prior to the Late Triassic magmatism.

scholarly journals Cenozoic reactivation along the Late Triassic Ganzi-Litang suture, eastern Tibetan Plateau

2020 ◽  
Vol 11 (3) ◽  
pp. 1069-1080 ◽  
Author(s):  
W.T. Jackson ◽  
D.M. Robinson ◽  
A.L. Weislogel ◽  
X. Jian
Keyword(s):  
Tibetan Plateau ◽  
Late Triassic ◽  
Eastern Tibetan Plateau

Late Triassic granitoids of the eastern margin of the Tibetan Plateau: Geochronology, petrogenesis and implications for tectonic evolution

Lithos ◽  
2007 ◽  
Vol 96 (3-4) ◽  
pp. 436-452 ◽  
Author(s):  
L. Xiao ◽  
H.F. Zhang ◽  
J.D. Clemens ◽  
Q.W. Wang ◽  
Z.Z. Kan ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Tectonic Evolution ◽  
Late Triassic ◽  
The Tibetan Plateau ◽  
Eastern Margin
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