[1] The NAC is bounded by the Nagssugtoqidian orogen to the north and the 1.8–1.87 Ga Ketilidan–Makkovik mobile belt to the south.
Throughout the Mesoproterozoic, Neoproterozoic, and Mesozoic (1350–550 Ma), when these blocks still formed a coherent craton, repeated continental extension resulted in lithospheric thinning.
Magmatism during the Neoproterozoic was caused by either the opening of the Iapetus Ocean, lithospheric thinning along a fracture zone, or the appearance of a mantle plume.
[4] In Greenland the NAC is primarily made of tonalite–trondhjemite–granodiorite orthogneisses separated and obscured by supracrustal belts, anorthosite complexes, and granite intrusions.
In the Kapisilik orogeny c. 2650–2580 Ma terranes around the Godthåbsfjord, mostly north of Nuuk, were accreted along the Iivinnguit fault.