Noah J Planavsky, Christopher T Reinhard, Xiangli Wang, Danielle Thomson, Peter McGoldrick, Robert H Rainbird, Thomas Johnson, Woodward W Fischer, Timothy W Lyons

2014/10/31

Science

346

6209

635-638

American Association for the Advancement of Science

Abstract The oxygenation of Earth's surface fundamentally altered global biogeochemical
cycles and ultimately paved the way for the rise of metazoans at the end of the Proterozoic.
However, current estimates for atmospheric oxygen (O 2) levels during the billion years
leading up to this time vary widely. On the basis of chromium (Cr) isotope data from a suite of
Proterozoic sediments from China, Australia, and North America, interpreted in the context of
data from similar depositional environments from Phanerozoic time, we find evidence for ...