Question

When geologists refer to the " Big Five", what are they referring to?

Answer 1

Number 2 is the right answer

hope it helps, murdle:)

Answer 2

Answer:

2) The five largest mass extinctions in earths history.

Explanation:

The five largest mass extinctions in earth's history were:

1. End Ordovician, 444 million years ago, 86% of the total species lost
2. Late Devonian, 375 million years ago, 75% of the total species lost
3. End Permian, 251 million years ago, 96% of the total species lost
4. End Triassic, 200 million years ago, 80% of the total species lost
5. End Cretaceous, 66 million years ago, 76% of all the total species lost