We report four late Palaeozoic zircon sensitive high-resolution ion microprobe (SHRIMP) U–Pb ages for granitic plutons from the Inner Mongolia Palaeo-uplift on the northern margin of the North China block. These cast a new light on the poorly understood tectonic history of the northern margin of the North China block and the Central Asian Orogenic Belt during the late Palaeozoic. The plutons have for a long time been considered to belong to the early Precambrian basement of the North China block. Our new SHRIMP U–Pb zircon dating of four plutons at Longhua, Daguangding, Boluonuo and Hushiha has yielded intrusive ages of 311 ± 2 Ma, 324 ± 6 Ma, 302 ± 4 Ma and 310 ± 5 Ma, respectively. Geochemical data suggest that these granitoids have a calc-alkaline, subduction-related I-type signature, indicating the existence of an Andean-style continental arc along the northern margin of the North China block during the late Palaeozoic. Our results also indicate that the Palaeo-Asian Ocean still existed during latest Carboniferous–earliest Permian time, and that the final collision between the southern Mongolia composite terranes and the North China block occurred later than c . 290 Ma. We suggest that the northern margin of the North China block was an active continental margin and the Inner Mongolia Palaeo-uplift is a deeply exhumed mid-crustal ‘root’ of a late Palaeozoic Andean-style continental arc.

Recent results show that evolution of the huge Central Asian orogenic belt can be explained in terms of southwest Pacific–style accretion of arcs and microcontinents. A better understanding of the origin and evolution of arcs and microcontinents will enhance our knowledge on the evolution of the Central Asian orogenic belt. As one of the most important early Paleozoic arc systems south to the Solonker suture zone, the origin and evolution of the Bainaimiao arc belt are still not well constrained. New zircon U-Pb geochronological and geochemical results on magmatic rocks in the Bainaimiao arc belt indicate that the arc was active from 0.52 Ga to 0.42 Ga and can extend to east Siping in NE China. Zircon U-Pb geochronological results of metasedimentary rocks in the Bainaimiao arc belt indicate that they are early Paleozoic in age, not Precambrian as previously regarded. Detrital zircon analysis of metasedimentary rocks and Sr-Nd-Hf geochemical results of magmatic rocks indicate the existence of some Proterozoic basement rocks beneath the Bainaimiao arc, and it was built upon a Precambrian microcontinent that has a tectonic affinity to the Tarim or Yangtze cratons. The Bainaimiao arc is an ensialic island arc characterized by different evolution history and basement compositions from the northern North China craton. It was separated by a wide ocean from the northern North China craton during the Cambrian–Ordovician period. Successive northward subduction resulted in contraction of the ocean and final accretion of the Bainaimiao arc to the northern North China craton during the Late Silurian–earliest Devonian by arc-continent collision. Arc-continent collision could be an important mechanism for continental crustal growth and formation of the huge Central Asian orogenic belt.