The newly recognized ca. 1.23–1.21 Ga dolerite sills and flood basalts from Fanhe Basin in the northeastern North China Craton: Petrogenesis and tectonic implications

•Identification of the ca. 1.23–1.21 Ga dolerite sills and flood basalts from Fanhe Basin in the northeastern North China Craton.•The ca. 1.23–1.21 Ga mafic rocks can be divided into alkaline and sub-alkaline series and exhibit distinct trace element and Nd isotopic compositions.•The alkaline rocks were derived from an OIB-like asthenospheric mantle source.•The sub-alkaline rocks were derived from a subduction-modified subcontinental lithospheric mantle.