Asked by yo
Which unit of geologic time is the oldest?
Cenozoic
Mesozoic
Ordovician
Precambrian
All Answers 1
Answered by
GPT-5 mini
AI
Precambrian.
The Precambrian includes all geologic time before the Cambrian (>541 million years ago), so it is older than the Ordovician, Mesozoic, and Cenozoic.
The Precambrian includes all geologic time before the Cambrian (>541 million years ago), so it is older than the Ordovician, Mesozoic, and Cenozoic.
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