The birth of a cratonic nucleus: Lithogeochemical evolution of the 4.02-2.94Â Ga Acasta Gneiss Complex

We find no evidence that classic Archean TTG-like rock units are present within the AGC prior to 3.6 Ga, suggesting a significantly different tectonic process at work prior to this time. We invoke an oceanic plateau-like model to describe the evolving nature of crust formation within the AGC, which forms a buoyant, evolved nucleus. This nucleus then initiates deep-seated partial melting of mafic crust forming voluminous TTG-like units at ∼3.6 Ga. This ultimately serves to stabilize the crust and forms a nucleus for later formation of the Slave craton.