Timing and processes of late Mesozoic mid-lower-crustal extension in continental NE Asia and implications for the tectonic setting of the destruction of the North China Craton: Mainly constrained by zircon U–Pb ages from metamorphic core complexes

Lithos ◽  
2012 ◽  
Vol 154 ◽  
pp. 315-345 ◽  
Author(s):  
Tao Wang ◽  
Lei Guo ◽  
Yadong Zheng ◽  
Tatiana Donskaya ◽  
Dmitry Gladkochub ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Tectonic Setting ◽  
Crustal Extension ◽  
Late Mesozoic ◽  
The North ◽  
Metamorphic Core Complexes ◽  
Lower Crustal ◽  
Metamorphic Core

Comparative studies on two phases of Archaean TTG magmas from different blocks of the North China Craton: petrogenesis and constraints on crustal evolution

2020 ◽  
pp. 1-16
Author(s):  
Houxiang Shan ◽  
Mingguo Zhai ◽  
RN Mitchell ◽  
Fu Liu ◽  
Jinghui Guo
Keyword(s):  
North China Craton ◽  
Lower Crust ◽  
North China ◽  
Tectonic Setting ◽  
Source Material ◽  
Crustal Growth ◽  
Garnet Amphibolite ◽  
The North ◽  
Western Block ◽  
Subducting Slab

Abstract Whole-rock major and trace elements and Hf isotopes of magmatic zircons of tonalite–trondhjemite–granodiorite (TTG) rocks with different ages (2.9, 2.7 and 2.5 Ga) from the three blocks (the Eastern Block, Western Block and Trans-North China Orogen) of the North China Craton were compiled to investigate their respective petrogenesis, tectonic setting and implications for crustal growth and evolution. Geochemical features of the 2.5 Ga TTGs of the Eastern Block require melting of predominant rutile-bearing eclogite and subordinate garnet-amphibolite at higher pressure, while the source material of the 2.7 Ga TTGs is garnet-amphibolite or granulite at lower pressure. The 2.5 Ga TTGs have high Mg#, Cr and Ni, negative Nb–Ta anomalies and a juvenile basaltic crustal source, indicating derivation from the melting of a subducting slab. In contrast, features of the 2.7 Ga TTGs suggest generation from melting of thickened lower crust. The 2.5 and 2.7 Ga TTGs in the Trans-North China Orogen were formed at garnet-amphibolite to eclogite facies, and the source material of the 2.5 Ga TTGs in the Western Block is most likely garnet-amphibolite or eclogite. The 2.5 Ga TTGs in the Trans-North China Orogen and Western Block were generated by the melting of a subducting slab, whereas the 2.7 Ga TTGs in the Trans-North China Orogen derived from melting of thickened lower crust. The Hf isotopic data suggest both the 2.5 and 2.7 Ga TTG magmas were involved with contemporary crustal growth and reworking. The two-stage model age (TDM2) histograms show major crustal growth between 2.9 and 2.7 Ga for the whole North China Craton.

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