Geochronology and petrogenesis of gray gneisses from the Taihua Complex at Xiong'er in the southern segment of the Trans-North China Orogen: Implications for tectonic transformation in the Early Paleoproterozoic

► Two episodic Early Paleoproterozoic magmatisms in the Taihua Complex at Xiong'er. ► The early TTG was derived from thickened lower crust with juvenile materials. ► The later K-rich rock was partial melting of crust at post-collisional setting. ► Tectonic transformation from accretionary orogenesis to extension setting at ~ 2.2 Ga.