Earth History Flashcards
(4 cards)
1
Q
Method of determining the time of origin of rocks by measuring the ratio of radioactive argon to radioactive potassium in the rock. Ar-40/K-40. Range 4.3 billion to 100,000 years
A
Potassium-argon dating
2
Q
When an animal or plant dies, it will not take in any more carbon, and the 14C present will begin to decay. We can thus measure how long it’s been since the animal or plant died by comparing the presence of 14C with the known half-life.
A
Carbon-14 dating
3
Q
The downside to carbon-14 dating
A
Can only date relatively recent materials . cant date anything older than 50,000 years because C14 decays quickly
4
Q
used to determine ages from 4.5 billion to 1 m years old.
A
Uranium-lead dating
