Hudson Bay. Photo source: ©© NK Eide
Excerpts;
Rocks from the eastern shore of the Hudson Bay in Canada contain elements of some of Earth’s earliest crust, new research finds.
The rocks themselves are granites that are 2.7 billion years old, but they still hold the chemical signals of the precursor rocks that were melted and recycled to form the rocks that exist today. The new study, published online today (March 17) in the journal Science, finds that these precursors formed around 4.3 billion years ago.
The Earth is 4.6 billion years old, and the astronomical impact that formed the moon took place about 4.5 billion years ago. That makes the precursor rocks to the Canadian granites among the earliest crust after the moon-forming impact, said study leader Jonathan O’Neil, a geoscientist at the University of Ottawa in Canada…
