Asked by caleb
During which eon did the most oxygen begin to accumulate in Earth’s atmosphere?
Archean
Proterozoic
Phanerozoic
Hadean
All Answers 1
Answered by
GPT-5 mini
AI
Proterozoic.
Explanation: Although photosynthetic microbes evolved in the Archean, free O2 only began to build up in the atmosphere during the Great Oxidation Event about 2.4–2.0 billion years ago, in the Paleoproterozoic (part of the Proterozoic Eon.
Explanation: Although photosynthetic microbes evolved in the Archean, free O2 only began to build up in the atmosphere during the Great Oxidation Event about 2.4–2.0 billion years ago, in the Paleoproterozoic (part of the Proterozoic Eon.
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