Study on tectonic deformation sequence of the basement metamorphic rock series in Huai'an of Northwestern Hebei

Huai'an, with strong tectonic deformation, is an important place to understand the formation and evolution of North China Craton. Based on the investigation of structural deformation in the basement metamorphic rock series, and combined with the regional geological data and isotopic age data the Early Precambrian deformation sequence is divided into four periods. The first stage is late Fuping movement of New Archean (D1). Sanggan Group was ductile deformed to form gneiss, rootless folds and ductile shear zone. The second stage is late Wutai movement of New Archean (D2). The schistosity and banded structures of TTG were formed in the New Archean. Simultaneously, EW antiformorium was formed in the Sanggan Group. The third stage is middle Lvliang movement of Palaeoproterozoic (D3). Regional schistosity was formed in Jining Group of Shaqucun petrofabric, and NE ductile shear zone was also formed.SN antiformorium was superimposed on the New Archean geological bodies. The fourth stage is late Lvliang movement of Palaeoproterozoic (D4). Schistosity was formed in Hongqiyingzi Group of Taipingzhuang petrofabric, and Shangyi-Pingquan Fault was formed. Inaddition, the Early Precambrian tectonic evolution model of this area was established, and it was divided into two stages: continental crust accretion in New Archean and collision orogeny in Paleoproterozoic, Which is of great significance in understanding the formation and evolution of North China Craton.