Radioactive dating fossils isotopes used
One creationist editor, who is more mellow than his unfortunate statement suggests, phrased the argument thus: Unfortunately the geologists date the rocks as the paleontologists tell them to. That passage might have come out of one of Henry Morris' books, except that Morris usually avoids crude slander. Hovind is not aware of the fact that by 1815 the broad outlines of the geologic column from Paleozoic times onward had been worked out by people who were mostly geologists.
Then the paleontologists use the geologists' dates as evidence for the age of the fossils! The relative order of the strata was first determined by the principles of stratification. Beagle, a very strong Bible believer, made it a point to have a copy of Lyell's book for the ship's library.
A further example from a lava flow off the coast of Hawaii shows similar discrepancies.
If dated with the carbon-14 method, the flow appears to be less than 17,000 years old, but dating with the potassium argon method gives dates of 160,000 to 43 million years.
If the clock is not set to zero when a deposit forms, then there can be no starting point from which to calculate the age of a deposit.
Carbon-14 comes from nitrogen and is independent of the carbon-12 reservoir.
If even a small percentage of the limestone deposits were still in the form of living marine organisms at the time of the Flood, then the small amount of carbon-14 would have mixed with a much larger carbon-12 reservoir, thus resulting in a drastically reduced ratio.
While there is no proof that the rates were different in the past than they are today, there is also no proof that they were the same.
Thus radioactive dating relies purely on assumptions.