The mathematical premise undergirding the use of these elements in radiometric dating contains the similar confounding factors that we find in carbon-14 dating method.Most scientists today believe that life has existed on the earth for billions of years.
Once our geologist had the “index fossil” that was found approximately in the same layer as the newly discovered fossil, he would then see where in the geologic column it came from and presto, he now had a date for his newly discovered fossil.
He would simply go to a chart that listed the geologic column by ‘ages’ and find the place where the index fossil appears, and thereby the geologists could tell the paleontologist how old his fossil was.
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.
Carbon dating cannot be used on most fossils, not only because they are almost always allegedly too old, but also because they rarely contain the original carbon of the organism that has been fossilized.