EGU2020-4504
https://doi.org/10.5194/egusphere-egu2020-4504
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Eoarchean to Paleoproterozoic crustal evolution in the North China Craton

Qiang Ma1,2, Yi-Gang Xu2, Xiao-Long Huang2, and Jian-Ping Zheng1
Qiang Ma et al.
  • 1School of Earth Sciences, China University of Geosciences, Wuhan, China (maqiang@cug.edu.cn; jpzheng@cug.edu.cn)
  • 2State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China (yigangxu@gig.ac.cn; xlhuang@gig.ac.cn)

The early evolution of continental crust, particularly its lower layer, during the first 2.0 billion years of Earth history remains enigmatic. Here, we present the first coupled in-situ U-Pb, Lu-Hf and O isotope data for the Precambrian zircons from fourteen deep-crustal xenoliths from five localities in the North China craton. The results show that: (1) the oldest (3.82−3.55 Ga) known lower crustal rocks were survived in the southern part of this craton; (2) the Eo-Paleoarchean zircons have predominant sub-chondritic Hf isotope compositions and elevated δ18O values, suggesting Lu-Hf fractionation and crust-hydrosphere interactions on the Earth can be traced back to Eoarchean or even earlier; (3) a secular change in zircon O isotopes documents an increase in recycling rate of surface-derived materials into magmas at the end of Archean, which, in turn, is possibly linked to modern style subduction processes and maturation of the crust at that time.

How to cite: Ma, Q., Xu, Y.-G., Huang, X.-L., and Zheng, J.-P.: Eoarchean to Paleoproterozoic crustal evolution in the North China Craton, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4504, https://doi.org/10.5194/egusphere-egu2020-4504, 2020