Results for: Proterozoic

How long did the Proterozoic eon last?

The Proterozoic eon was the third eon in Earth history. It lasted from 2.5 billion years ago to 542 million years ago. Therefor, the Proterozoic was nearly 2 billion years lon (MORE)

What do Proterozoic-aged red beds and banded iron formations tell us about the Earth's early atmosphere?

Banded iron formations indicate that there were oxygen-rich and oxygen-poor episodes during Earth's early atmosphere. Banded iron formations first appear in the Archean, 3 bil (MORE)