the largest ethnic groups in North Africa are Arabs, Berbers and West Africans. I hope this helps :P
Explanation:
I may be completely incorrect but I think its shifting/plates hitting each other.
Jack Hills, Australia, where rocks were found to contain the oldest known minerals on Earth, a 4.4 billion-year-old zircon. Just three of the very oldest zircons have been found, ones that date back to almost 4.4 billion years ago. Their extreme age <span>always makes the dates suspect, because of possible radiation damage. </span>
