Late early Paleozoic continental collision on the northern margin of the Central Qilian Block, NE Tibetan Plateau: Evidence from a two-stage tectono–metamorphic event

The central part of the Qilian orogenic belt (QOB) on NE Tibetan Plateau is known as Central Block (CQB), and research deformation metamorphism CQB improves our understanding tectonic evolution QOB, which makes up an important continental crust in eastern Asia. Here we present results thermobarometric calculation geochronological analyses for deformed metamorphic rocks northern margin CQB, these new datasets provide a record collision CQB. Macrostructures microstructures indicate that underwent dextral ductile deformation. C-axis fabrics dynamic recrystallisation quartz took place at temperatures 400–500 °C. In contrast, phase equilibrium modelling suggests region HT–MP along clockwise P–T path, with peak conditions ∼ 740 °C 7.2 kbar. Zircon U–Pb ages obtained from zircon rims 452–449 Ma. petrographic changes garnet porphyroblasts due to late deformation, shearing after metamorphism. records different are consistent multi-stage metamorphism–deformation. Together previous metamorphism, magmatism, confirm were developed during Alxa Block.