Some early unmetamorphosed and undeformed mafic dyke swarms in North China, Southern Peninsular India and North America share coeval age of ~ 1.85 Ga. If these continents are assembled, the overall pattern exhibited by the mafic dyke swarms appears to constitute a giant radiating swarm, with a piercing point between the Cuddapah rift in South India and the Xiong'er aulacogen in North China. This suggests that the North China Craton, Indian Craton and Canadian Shield may be fragmented from the same landmass. The reconstruction of ~ 1.85 Ga giant radiating dyke swarm attempted in this paper suggests that the North China Craton, India Craton and Canadian Shield were united together to form a landmass within the Columbia supercontinent before its extension and break-up.
The 1.90–1.85 Ga Andean-style North Orogenic Belt suggests that a subduction zone existed on the northern margin of the North China Craton. Wopmay Orogenic Belt developed in a 1.88–1.84 Ga continental volcano-plutonic arc, which is interpreted as the product of eastward subduction of oceanic lithosphere. The Transantarctica Orogenic Belt in East Antarctica may be another candidate to be linked with the subduction zone. The North Orogenic, Wopmay Orogenic and Transantarctica Orogenic Belts could be connected to form a continuous subduction zone. The orogenic comparison strengthens the configuration of the Columbia supercontinent proposed by the reconstruction of the giant radiating dyke swarm. The Laurentia, West Australia and East Antarctica were relatively stable from 1.85 Ga to 1.20 Ga as inferred from the data on dyke swarms, magmatism and the paleomagnetism. These continents constituted the core of the Columbia supercontinent in the Late Paleoproterozoic time. The North China Craton and Indian Craton were however separated from the Columbia supercontinent during the Mesoproterozoic time.
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