Which type of age dating uses radioactive decay
The only problem is that we only know the number of daughter atoms now present, and some of those may have been present prior to the start of our clock. The reason for this is that Rb has become distributed unequally through the Earth over time.We can see how do deal with this if we take a particular case. For example the amount of Rb in mantle rocks is generally low, i.e. The mantle thus has a low If these two independent dates are the same, we say they are concordant.A billion years after that rock was formed, the rock is covered and remelted by a lava flow.
If your mom walked in and saw 1/16th of a pie (and knew that you had been eating half of what was left every day), she could quickly determine that the pie was four days old. Some elements (uranium, for example) are unstable, and decay to a different element (uranium to lead, for example). The first day you eat half the pie, and save the other half for later.The second day you eat half of what's left (leaving 1/4 of the original pie).The age of the carbon in the rock is different from that of the carbon in the air and makes carbon dating data for those organisms inaccurate under the assumptions normally used for carbon dating.This restriction extends to animals that consume seafood in their diet.