An analysis of rock samples collected from the Superior Province, the region in Canada just north of the Great Lakes, suggests the samples contain components of ancient basaltic crust that existed more than 4.2 billion year ago (Hadean eon). An artistic conception of the early Earth. Image credit: Simone Marchi / NASA. Recreating the nature of Earth’s first crust is difficult because geologic activity has created turnover that drove most of it back...
