Granulite facies metamorphism and crust melting in the Huai’an terrane at ∼1.95Ga, North China Craton: New constraints from geology, zircon U–Pb, Lu–Hf isotope and metamorphic conditions of granulites

2016 ◽  
Vol 286 ◽  
pp. 126-151 ◽  
Author(s):  
Hao-Zheng Wang ◽  
Hua-Feng Zhang ◽  
Ming-Guo Zhai ◽  
Elson Paiva Oliveira ◽  
Zhi-Yao Ni ◽  
...  
Keyword(s):  
North China Craton ◽  
North China ◽  
Granulite Facies ◽  
Hf Isotope ◽  
Granulite Facies Metamorphism ◽  
Facies Metamorphism

Arc-related peridotite blocks exhumed to the Eastern Block of the North China Craton prior to 2.47 Ga

2021 ◽  
pp. 1-24
Author(s):  
Mingyue Gong ◽  
Wei Tian ◽  
Zhuang Li ◽  
Bin Fu ◽  
Chunjing Wei
Keyword(s):  
North China Craton ◽  
North China ◽  
Mantle Wedge ◽  
Granulite Facies ◽  
Granulite Facies Metamorphism ◽  
Melt Extraction ◽  
The North ◽  
Mantle Peridotites ◽  
Facies Metamorphism ◽  
Light Rare Earth Elements

Abstract The Songling and Majiayu peridotite blocks occur in the Eastern Block, North China Craton (NCC). Geothermobarometry data show that the Songling peridotites began exhumation from a depth of c. 70 km (c. 23 kbar). During exhumation, the Songling peridotites were intruded by an upper-crust-derived, high-δ18O (up to +7.28‰ in zircon) trondhjemitic dyke at 2.47 Ga and experienced granulite-facies metamorphism. The Songling peridotites have hybrid mantle wedge (HMW) -like high SiO2 (> 45 wt%), high FeOt (c. 10 wt%) content, high modal orthopyroxene abundance (> 35%) and high ϵNd(t) (+18.4 to +21.4), which were generated by the reaction between peridotite and eclogite-derived melts. The clinopyroxenes from the Songling peridotites were in equilibrium with a Nb-, Zr- and Ti-depleted arc-like magma. The Majiayu peridotites are characterized by depletion of Nb, Zr and Hf and are highly enriched in FeOt, Th and light rare earth elements (LREEs), which can be interpreted as an open system reaction between hydrous melts and fore-arc mantle peridotites. These two peridotite blocks are considered to be arc-related mantle peridotites that experienced melt extraction and metasomatism in different styles. They were exhumed to the north margin of the North China Craton during the c. 2.47 Ga arc–continent collision along the Zunhua structural belt.

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