Creationist dating methods
For if extra daughter element were added, then we should arrive at too large a figure for the amount of the parent element that has decayed, and thus produce too high a value for the age of the rock.) Geologists are not unaware of these assumptions, and they take great pains to construct ways of cross-checking them.
Argon is an inert gas, so that it does not occur in chemical compounds in original rocks.
If extra lead were to have been absorbed in the rock after the original formation, the new lead would have caused the calculated ages of the rock to diverge unless it contained the right proportion of lead-206 to lead-207.
If the ratio of lead-206 to lead-207 in the newly introduced rock were greater than the ratio of lead-206 to lead-207 found in an uncontaminated system, the method of dating based on the decay of uranium-238 to lead-206 would give a relatively higher value than the method of dating based on the decay of uranium-235 to lead-207.
A second, independent, astronomical method is to use standard techniques to measure some parameters of stars (mass, luminosity, compositor, and surface temperature), from which a well-confirmed theory of the life histories of stars enables physicists to compute their. Finally, considerations of radioactive decay make it possible to calculate the time at which certain heavy elements were formed.
These techniques are somewhat similar to the radiometric methods of dating rocks, which I shad consider in a little more detail.
In the second case, the existence of two separate decay processes provides a check on the assumption that the system has not been contaminated.Here it is possible to use two decay processes, the decay of uranium-238 into lead-206 and the decay of uranium-235 into lead-207.Furthermore, the amount of lead originally present can be computed by considering another isotope of lead.The ages assigned to various rock strata bearing distinctive types of fossils show extraordinary agreement. We have already discussed statements akin to Morris's first and second assumptions.The many independent computations of the age of the earth during the last three decades almost invariably yield a figure between 4.2 and 4.8 billion years. As will become clear shortly, the status of the third is a little different.