This is geography not math
The Sahel<span> is the zone of transition, in Africa.</span>
Answer:
Zicrons
Explanation:
The oldest of the zircons in the study, which came from the Jack Hills of Western Australia, were around 4.3 billion years old—which means these nearly indestructible minerals formed when the Earth itself was in its infancy, only roughly 200 million years old.
