Radiometric dating on sedimentary rocks
Back to top Radioactive elements decay gradually into other elements.
The original element is called the parent, and the result of the decay process is called the daughter element.
When it is stated that these methods are accurate to one or two percent, it does not mean that the computed age is within one or two percent of the correct age.
It just means that there is enough accuracy in the measurements to compute t to one or two percentage points of accuracy, where t is the time required to obtain the observed ratio of daughter to parent, assuming no initial daughter product was present at the beginning, and no daughter or parent entered or left the system.
Perhaps the earth was made from older pre-existing matter, or perhaps decay rates were briefly faster for some reason. Geologic time is divided up into periods, beginning with the Precambrian, followed by the Cambrian and a number of others, leading up to the present.
When one considers the power of God, one sees that any such conclusions are to some extent tentative. Some fossils are found in Precambrian rocks, but most of them are found in Cambrian and later periods.
We can assume that the Precambrian rocks already existed when life began, and so the ages of the Precambrian rocks are not necessarily related to the question of how long life has existed on earth.
We are told that these methods are accurate to a few percent, and that there are many different methods.
Thus radiometric dating methods appear to give evidence that the earth and meteorites are old, if one accepts the fact that decay rates have been constant.
However, there may be other explanations for this apparent age. I also believe that the evidence indicates that the earth has recently undergone a violent catastrophe.
Since there doesn't seem to be any systematic error that could cause so many methods to agree with each other so often, it seems that there is no other rational conclusion than to accept these dates as accurate.
However, this causes a problem for those who believe based on the Bible that life has only existed on the earth for a few thousand years, since fossils are found in rocks that are dated to be over 500 million years old by radiometric methods, and some fossils are found in rocks that are dated to be billions of years old.