A paradigm shift: North China Craton's North Margin Orogen is the collisional suture with the Columbia Supercontinent

In a new study, Wu et al. (this issue) present a comprehensive study of the North Margin Orogen of the North China Craton, showing that older accreted rocks in this belt preserve a record of active margin magmatism from 2.2-2.0 Ga, followed by collisional tectonics, marked by mélange and mylonitic shear zones, then granulite facies metamorphism at 1.9-1.8 Ga, marking the final collision of the North China Craton with the Columbia Supercontinent. The multidisciplinary studies present in this work support earlier suggestions that the North China amalgamated during accretionary orogenesis in the Neoarchean to earlier Paleoproterozoic, and that the late widespread 1.85 Ga high-grade metamorphism is craton-wide in scale, and not confined to a narrow orogen in the center of the craton. This new understanding creates new possibilities for refining reconstructions of one of Earth’s earliest, best documented supercontinents, showing a globally-linked plate network at 1.85 Ga, and suggests drastic new correlations and models for mineral resource exploration.