A rock on the oldest Hawaiian island is found to around 65 million years old when using two different dating techniques.
One group of scientists used Sm-146 and found about 95%
of the element had decayed over that time frame. A separate
group used potassium-40 and found only about 10% of the
potassium had decayed over that same time frame. What
could cause these two measurements to be different? How could these two different elements date the same rock to
the same age?