Sweet! The Canadian shield is pretty cool! As an aside, this is Precambrian rock. Paleozoic is the name of the "Stone Age", starting around 3 Ma (million years ago) with hominids inventing stone tools. The Precambrian was approx 4.6 Ga (billion years ago) to 538 Ma. The exposed Canadian shield is roughly 2.5 to 4.2 Ga, depending on location.