New evidence of a two billion years old oxygen disaster found in Karelia
A well 3.5 km deep was drilled near Karelian Novinka settlement, Medvedev explained. A 800-meter sequence of rocks was extracted, which formed some 2.1 billion years ago. Scientists from Russia, the United States, Great Britain, Norway, and Estonia, under the guidance of Clara Bletler, a geochemist from Princeton University, investigated the minerals found to make out the dynamics of the chemical composition of air in the Paleoproterozoic era.
The scientists found a high content of sulphates, and came to a conclusion that the oxygen level increased sharply in a very short period of time — about 200−300 thousand years. Sulphates formed in water rich in oxygen.