These assumptions are: (1) the radioactive element decays at a constant rate (2) the rock crystal being analyzed is not contaminated by infusion of excess end product (3) the rock crystal contained no end product when it was formed (4) leaching of the parent element out of the rock sample did not occur.The Potassium-Argon dating method suffers from both leaching and contamination problems.Leaching of the parent element out of the rock would increase the age of a K-Ar sample.
Let us critically examine each of these claims and see if they hold up against the science.
While doing so, we will have to learn about how radiometric dating works.
Therefore, since sedimentary rock is the only kind of rock that bears fossils, a relative date is estimated by the position of a sedimentary rock in relation to an igneous outflow.
There is a discussion of a few examples of radiometric methods with sedimentary rocks in Creationists believe that the assumptions of radiometric dating are invalid and cannot be proven.
This would reduce the concentration of the potassium ions to the point that it would increase the date of the rock dramatically. Helens rock known to have come from the 1980 eruption (Creation Ex Nihilo Technical Journal) yielded erroneous dates in the millions of years.
I have heard that this experiment has been done, demonstrating this effect (I am searching for the reference). Similar studies at the Grand Canyon found volcanic rocks dated at the top of the canyon older than those found in the bottom. One of the tests that has not been done on the method is to subject it to a double blind study.
There are many different kinds of radiometric dating and not all conclusions we will reach can be extrapolated to all methods used.
Also, different radiometric dating techniques independently converges with each other and with other dating techniques such as dendrochronology, layers in sediment, growth rings on corals, rhythmic layering of ice in glaciers, magnetostratigraphy, fission tracks and many other methods. There exists different versions, or isotopes of many elements.
That is, you can see if the sample comes from rocks that have been disturbed (or contaminated) or not just by looking at the results.