The Guttenberg carbon excursion
A worldwide isotope shift records carbon burial and cooling in the run-up to the ice age.
- When
- Known to
- ± 3 million years
- Era
- Ordovician, Paleozoic
The Guttenberg Carbon Isotope Excursion, around 453 million years ago, marks a substantial positive shift in marine carbon isotopes tied to increased organic carbon burial. It coincides with a step down in atmospheric carbon dioxide and with faunal turnover, and it is used to correlate Late Ordovician rocks worldwide. It is one of several chemical signals showing the climate deteriorating well before the glaciation itself.