XX XX
x xx
XXX
x
XXXX
Xxxt
Figure A.
8. What type of unconformity is D?
XX
f
+
KK
0. What is the half-life of the isotope in Question 9?
t
X
tr
xxx
t
t
1. Give an indirect numerical age of the rock unit above D.
***
xxx
9. The rock unit below D was dated at 60 million years old. The rock contained 50% parent atoms and 50%
daughter atoms. How many half-lives have passed?
D