High-Mg adakitic rocks in the Dabie orogen, central China: Implications for foundering mechanism of lower continental crust

2008 ◽  
Vol 255 (1-2) ◽  
pp. 1-13 ◽  
Author(s):  
Fang Huang ◽  
Shuguang Li ◽  
Feng Dong ◽  
Yongsheng He ◽  
Fukun Chen
Keyword(s):  
Continental Crust ◽  
Central China ◽  
Dabie Orogen ◽  
Lower Continental Crust ◽  
Adakitic Rocks

scholarly journals Iron Isotope Composition of Adakitic Rocks: The Shangcheng Pluton, Western Dabie Orogen, Central China

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1356
Author(s):  
Chenglai Deng ◽  
Changqing Hu ◽  
Ming Li ◽  
Wu Li
Keyword(s):  
Isotopic Composition ◽  
Partial Melting ◽  
Isotope Composition ◽  
The Other ◽  
Central China ◽  
Iron Isotopes ◽  
Iron Isotope ◽  
Dabie Orogen ◽  
Adakitic Rocks ◽  
New Evidence

There has been little research on the metal isotopic composition of adakitic rock. The main objective of our investigation was to obtain more knowledge on the iron isotopic composition of adakitic rocks and provide new evidence for the genesis of Shangcheng pluton from an iron isotope perspective. The Dabie orogen is divided into eastern and western areas by the Shangcheng-Macheng fault, and the Shangcheng pluton is located in the western Dabie orogen area. The iron isotopic composition of these rocks ranges from 0.08‰ to 0.20‰ (2SD, n = 3). The δ56Fe values of two rocks from the SGD (Sigudun) unit are relatively low (0.11 ± 0.03‰ and 0.08 ± 0.04‰), while the δ56Fe values of the other samples are basically consistent (0.18–0.2‰). Evidence from elemental geochemical characteristics and petrogenesis defines the Shangcheng pluton as adakitic rocks. Our investigation on the elemental and isotopic compositions hints that the enrichment of heavy iron isotopes cannot be explained by weathering/alteration and fluid exsolution. Fractional crystallization of magnetite may account for the enrichment of light iron isotopes in two rocks from the SGD unit, while the fractional iron isotope trend in the other five samples can be explained by Δ56Fecrystal-melt = ~0.035‰. Two investigated rocks from SGD units may have been derived from the partial melting of amphibolite, while the other five samples may have been derived from the partial melting of eclogite containing 10–15% garnet.

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