The Late Carboniferous to Early Permian high silica magmatism in the Southern Mongolia: Implications for tectonic evolution and continental growth

•The ~315–310 Ma crust-derived granites of the Khan-Bogd area possibly resulted from low-angle subduction.•The ~290 Ma A-type granites and coeval bimodal magmatism suggest a slab breakoff extension.•This slab breakoff probably indicates a tectonic transition of post collision from subduction-accretion.•It plays an important role for the vertical crustal growth during the final episode of the CAOB evolution.