Radiometric dating Flashcards
1
Q
Law of superposition
A
younger rocks on top
2
Q
Index rock
A
can also be used to show the
approximate ages of rock. Fossils in different rock
layers can be compared to determine one rock
layers age in relation to another’s
3
Q
Possible problem when looking at strata
A
Unconformity - gap in rock sequence
4
Q
Why would unconformity occur
A
erosion, uneven deposition, earthquakes and plate movement
5
Q
How does radioactive dating work
A
look for evidence of decay in minerals that would have radioisotopes
6
Q
What is half life
A
The half-life of an unstable isotope is the amount of time for the mass of the unstable isotope to decrease by ½.
7
Q
What is the half life equation
A
Final quantity = Original amount times (1/2) to the power of (time/half life of substance)
8
Q
A
