Geochronology, geochemistry, origin, and tectonic implications of high‐pressure mafic granulites of the Amdo region, Central Tibet

2020 ◽  
Vol 55 (11) ◽  
pp. 7458-7473
Author(s):  
Chaoming Xie ◽  
Yuhang Song ◽  
Menglong Duan ◽  
Li Su ◽  
Yujie Hao
Keyword(s):  
High Pressure ◽  
Tectonic Implications ◽  
Central Tibet

Ultra-high pressure minerals in the Luobusa Ophiolite, Tibet, and their tectonic implications

2004 ◽  
Vol 226 (1) ◽  
pp. 247-271 ◽  
Author(s):  
Paul T. Robinson ◽  
Wen-Ji Bai ◽  
John Malpas ◽  
Jing-Sui Yang ◽  
Mei-Fu Zhou ◽  
...  
Keyword(s):  
High Pressure ◽  
Ultra High Pressure ◽  
Tectonic Implications

Amalgamation of the Qiangtang terranes, central Tibet, and new insights into the mechanism of exhumation of high-pressure rocks

2015 ◽  
Vol 97 (1) ◽  
pp. 124-124
Author(s):  
PD Bons ◽  
Z Zhao ◽  
E Gomez-Rivas ◽  
A Soesoo ◽  
E Burov ◽  
...  
Keyword(s):  
High Pressure ◽  
Central Tibet

40Ar/39Ar dating of white micas from the epidote to the omphacite zones, northern New Caledonia: tectonic implications

1994 ◽  
Vol 31 (6) ◽  
pp. 995-1001 ◽  
Author(s):  
E. D. Ghent ◽  
J. C. Roddick ◽  
P. M. Black
Keyword(s):  
High Pressure ◽  
New Caledonia ◽  
Thermal Modeling ◽  
Closure Temperature ◽  
Metamorphic Rocks ◽  
Areal Extent ◽  
Rock Samples ◽  
Tectonic Implications ◽  
Cooling Unit

An 40Ar/39Ar study of white micas from high-pressure metamorphic rocks of northern New Caledonia yielded cooling ages of 37 ± 1 Ma for both epidote and omphacite zone samples. Whole-rock samples from the lawsonite zone yielded ages in the range 44–51 Ma with complicated age spectra, probably reflecting both detrital and newly grown micas. The areal extent of the mica samples, over 300 km2, suggests that the epidote and omphacite zone rocks cooled through the muscovite closure temperature, about 350 °C, as a coherent cooling unit. Simple thermal modeling suggests that these rocks could have closed at similar times if the unroofing rate were greater than 2–10 mm∙a−1. Lawsonite zone rocks occur structurally within about 0.5 km of garnet–omphacite rocks, suggesting the possibility of major postmetamorphic tectonic displacement.

scholarly journals Tectonic evolution and high-pressure rock exhumation in the Qiangtang Terrane, Central Tibet

2015 ◽  
Vol 7 (1) ◽  
pp. 329-367 ◽  
Author(s):  
Z. Zhao ◽  
P. D. Bons ◽  
G. Wang ◽  
A. Soesoo ◽  
Y. Liu
Keyword(s):  
High Pressure ◽  
Tectonic Evolution ◽  
Late Triassic ◽  
The South ◽  
Metamorphic Belt ◽  
The North ◽  
Ophiolitic Mélange ◽  
Basement Rocks ◽  
Central Tibet ◽  
Qiangtang Terrane

Abstract. Conflicting interpretations of the > 500 km long, east-west trending Qiangtang Metamorphic Belt have led to very different and contradicting models for the Permo-Triassic tectonic evolution of Central Tibet. We define two metamorphic events, one that only affected Pre-Ordovician basement rocks and one subduction-related Triassic high-pressure metamorphism event. Detailed mapping and structural analysis allowed us to define three main units that were juxtaposed due to collision of the North and South Qiangtang terranes after closure of the Ordovician-Triassic ocean that separated them. The base is formed by the Precambrian-Carboniferous basement, followed by non-metamorphic ophiolitic mélange, containing mafic rocks that range in age from the Ordovician to Middle Triassic. The top of the sequence is formed by strongly deformed sedimentary mélange that contains up to > 10 km size rafts of both un-metamorphosed Permian sediments and high-pressure blueschists. We propose that the high-pressure rocks were exhumed from underneath the South Qiangtang Terrane in an extensional setting caused by the pull of the northward subducting slab of the Shuanghu-Tethys. High-pressure rocks, sedimentary mélange and margin sediments were thrust on top of the ophiolitic mélange that was scraped off the subducting plate. Both units were subsequently thrust on top of the South Qiantang Terrane continental basement. Onset of Late Triassic sedimentation marked the end of the amalgamation of both Qiangtang terranes and the beginning of spreading between Qiantang and North Lhasa to the south, leading to the deposition of thick flysch deposits in the Jurassic.

Palaeomagnetism and detrital zircon U-Pb geochronology of Cretaceous redbeds from central Tibet and tectonic implications

2017 ◽  
Vol 53 (5) ◽  
pp. 2315-2333 ◽  
Author(s):  
Jun Meng ◽  
Xixi Zhao ◽  
Chengshan Wang ◽  
Hao Liu ◽  
Yalin Li ◽  
...  
Keyword(s):  
Detrital Zircon ◽  
Tectonic Implications ◽  
Central Tibet
Sign in / Sign up

Export Citation Format

Share Document