Eons: Geological Time Flashcards
1
Q
What are the four eons of Earth’s history (oldest to youngest)?
A
- Hadean
- Archean
- Proterozoic
- Phanerozoic
2
Q
Which eon marks the origin of life?
A
Archean Eon (around 3.8 billion years ago)
3
Q
In which eon do most major marine phyla appear?
A
Phanerozoic Eon
4
Q
What event ended the Cretaceous Period?
A
Chicxulub asteroid impact and massive volcanic activity
5
Q
What caused the Permian extinction?
A
Likely volcanic activity, ocean anoxia, climate warming
