摘要
We studied an Archean mafic dike in the TransNorth China Orogen of the North China Craton, which has a magmatic age of 2701 ± 83 Ma and is currently the oldest mafic dike in the North China Craton. Such an old dike is extremely rare in the world. The presence of mafic dikes indicates that the North China Craton was in a tensional tectonic environment at 2.7 Ga. Geochemical characteristics reveal that this mafic dike belongs to continental tholeiitic basalt. Results from Hf isotope analysis reveal that the mafic dike originates from a depleted mantle. The plate assembly in the North China landmass was realized during the Archean era(2.7 Ga), and a thick and stable continental crust was formed. Therefore, the first cratonization of the North China Craton was completed before 2.7 Ga. The intrusion of the 2.7-Ga-old mafic dike from the deep lithospheric mantle of the continent indicates that the North China Craton has undergone a period of extensional tectonic activity. This event marks a significant extensional event that occurred after the cratonization of the North China Craton.
基金
supported by the open fund from the Key Laboratory of Deep-Earth Dynamics of Ministry of Natural Resources,Institute of Geology,Chinese Academy of Geological Sciences (Number J1901-16)
the project of graduate education and teaching reform in Shanxi Province (Number 2021YJJG147)
the teaching reform project"Geographic Modeling,Simulation and Visualization"established by Shanxi Normal University (Number2019JGXM-39)
"The Research Start-up Fund of Shanxi Normal University for Dr.Peng Chong in 2016"(Number 0505/02070438)
"The Research Start-up Fund of Shanxi Normal University for Dr.Liu Haiyan in 2017"(Number 0505/02070458)
"The Research Fund for Outstanding Doctor in 2017"(Number 0503/02010168),established by the Education Department of Shanxi Province for Dr.Liu Haiyan。
