Making and breaking Columbia (Nuna): formation of a critical metal province? A North Atlantic view

The Palaeoproterozoic supercontinent of Columbia (Nuna), assembled at 2.1-1.8 Ga, included almost all of the Earth’s cratonic blocks (Zhao et al. 2004). Following assembly of the cratons along collisional orogens, accretionary tectonomagmatic belts developed along the supercontinent margins. The margins of the Archaean craton in Greenland are marked by the Paleoproterozoic Nagssugtoqidian orogen to the north, and Ketilidian accretionary belt to the south. In Scandinavia, the Svecofennian orogen and the Lapland-Kola belt are of similar age. Between these two areas lies the Lewisian Complex of NW Scotland, comprising Archaean crust reworked in the Palaeoproterozoic