Molly channelPosted on 2019 December
Plus evidence for each using scientific measurements of carbon isotopes. The decay constants for most of these systems have been confirmed in other ways, adding strength to our argument for the age of the earth. Why is zircon the preferred mineral for obtainting U - Pb dates? Radiocarbon activity of materials in the background is also determined to remove its contribution from results obtained during a sample analysis.
For an example of how geologists use radiometric dating, read on: A geologist can pick up a rock from a mountainside somewhere, and bring it back to the lab, and separate out the individual minerals that compose the rock. After a plants die, the incorporation of all carbon isotopes, including 14C, stops and the concentration of 14C declines due to the radioactive decay of 14C following. Most minerals will lose Ar on heating above oC - thus metamorphism can cause a loss of Ar or a partial loss of Ar which will reset the atomic clock. References Hua, Quan. Theoretically it can be used for samples that date from the beginning of the earth 4.