Oxygen's first peak — and crash
The carbon signal swings harder than at any time since
See it on the timeline →In depth
The Lomagundi–Jatuli event is the largest positive carbon isotope excursion in all of geological time, recorded in carbonates worldwide. The interpretation is that an extraordinary amount of organic carbon was buried, which releases oxygen. Estimates for oxygen levels during this interval vary widely, but several point to values near today's. Then the signal collapsed, and oxygen fell to a few per cent of modern levels in what becomes the "boring billion". Why the surplus did not hold is unresolved — candidates include phosphorus depletion, changed volcanic activity, and the simple absence of ecological machinery able to exploit oxygen.
For children
Just after oxygen arrived it suddenly rose far higher than before — perhaps as high as today. Then it fell again and stayed low for over a billion years. We do not fully know why, and it is one of the great puzzles in Earth's history.
Connects to
Part of Terra Saga — the story of Earth on a timeline. terrasaga.org