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Fossil and Radioisotope Dating

Dating Igneous and Metamorphic Rock

Although the subject of radioisotope dating may seem a bit complicated, the dating method is rather straightforward. Igneous and metamorphic rocks, which were once extremely hot and have cooled into solid rock, are dated using the following methods: uranium-238 to lead-206, uranium-235 to lead-207, potassium-40 to argon-40, and rubidium-87 to strontium-87, and are viewed as capable of providing an “absolute” age since solidification. However, these methods make the following assumptions: a constant rate of decay, a closed geologic system, and known amount of isotopes at the beginning.


Isotopes are several different forms of the same element. An isotope of uranium-238 can decay into an isotope of another element at a certain rate. The initial isotope is called the “parent” and the final isotope is called the “daughter.” Nuclear decay involves the breakdown of the atom on a subatomic scale by emitting radiation (alpha and beta particles, and gamma rays)—thus, the original atom becomes an entirely different kind of atom or element. For example, uranium-238 (parent isotope) decays into thorium-234, which itself is unstable, and the process continues until the atom changes into lead-206 (daughter isotope), which is stable.

Advocates of these methods assume that melting or liquid magma at the beginning resets the age clock to zero (that is, there are no daughter isotopes in the rock at the time of cooling or solidification). If the rate of decay from uranium to lead is constant (with a half-life of 4,470 million years), and if we know the amount of daughter isotopes in the rock at the beginning, and if we can measure how much parent and daughter isotopes are present in a given rock sample, we can supposedly calculate the age of the rock.

The isochron method, based on least squares regression, does not address rate of decay, and attempts to address assumptions 2 and 3, but results have been found to be discordant, “commonly fail at some level,” and are essentially meaningless. According to RATE scientists In 1997 a group of seven distinguished scientists met to review the assumptions and procedures used in estimating the ages of rock strata. This research project is identified as RATE (Radioisotopes and the Age of the Earth).44 The book, DeYoung, D. (May 2006). Thousands ... Not Billions, reviews eight years of research. (Master Books, Green Forest, AR, May 2006), radioisotope dating (including isochron radioisotope dating) is based on three assumptions that “commonly fail at some level.”47 These assumptions are: 1) constant rate of decay over supposedly hundreds of millions of years,
2) no loss or gain of parent or daughter isotopes over the supposed many millions of years of earth’s history (that is, there is no mixing of the magma and crustal rocks resulting in loss or gain of isotopes),
3) known amounts of daughter isotopes at the time of cooling.

The first assumption is a constant rate of radioactive decay based on uniformity theory—that is, a doctrine which maintains that natural processes have remained constant during earth’s history. It assumes radioactive decay has never been interrupted by worldwide cataclysmic events.

Scientists do not disagree with the amount of daughter isotopes found in rock formations, but rather the constancy of the rate of decay. There is ample evidence to suggest that nuclear decay was accelerated on two occasions: during creation week of Genesis 1 (expansion of the universe from an extremely hot, dense phase when matter and energy were concentrated) and during the year of the Flood (Genesis 7 and 8).

Such enormous tectonic events would cause accelerated nuclear decay48 which, in turn, would result in a profusion of observed daughter isotopes. This would erroneously provide results in the millions or billions of years—and would thereby invalidate radioisotope dating techniques.

Is there solid scientific evidence in favor of accelerated decay? According to RATE scientists, the answer is Yes. Such evidence includes an abundance of zircon crystals (containing a large component of helium atoms), and radiohalos and fission tracks in igneous rocks.49 These evidences have been thoroughly discussed in the 2006 book, Thousands … Not Billions, by Dr. D. DeYoung. Other substantial evidences are rapid magnetic field reversals and decay.50 Further evidence includes variations in isotope ratios in the meteorite, Allende, concluding that the decay rate is unstable.51 Such findings in meteors imply accelerated nuclear decay and fit well with findings of creation research scientists.

The second assumption assumes a closed geologic system—that is, no uplift, folding, and thrusting of the earth’s crust. This is, of course, contrary to the geologic landforms that are observed today. This assumption is fictitious—large scale migrations of elements suggest that parent/daughter (P/D) ratios are meaningless.

The third assumption is invalidated by discordant dates—that is, different dating techniques do not agree with each other or with known historic dates and by consistently finding vast ages from recently solidified magma. This indicates that something is fundamentally wrong with the dating technique. Scientists have attempted to account for inherited daughter isotopes at the start of cooling by using the isochron technique (regression analysis), but the technique is simply unable to differentiate between inherited daughter isotopes and non-inherited daugher isotopes.

This assumption can actually be tested today. If the dating technique is accurate, then age derived from recent eruptions should be too young to measure—it should indicate NO age but it consistently finds vast ages from recently solidified magma (worldwide).   • Mt. St. Helens in 1980 provides a radioisotope age of 2.8 million years although the rock was    only 15 years old,
• Mt. Kilauea of Hawaii provides a radioisotope age of 21 million years although rock is less than    200 years old,
• New Zealand volcano (Mt. Ngauruhoe) provides radioisotope ages of 133 million, 197 million    and 3.9 billion years (different techniques) although rock is less than 50 years old.

Why should anyone believe radioisotope dates provided by secular scientists if dates from recently solidified rocks indicate vast ages? So what is happening? Why do "recent" lavas indicate millions or billions of years? First of all, daughter isotopes are present at the start—contrary to assumption 3. 

In the beginning when the universe was expanding and accelerating at inconceivable rates, daughter isotopes (Pb-206 and Ar-40) would have been present. Large concentrations of daughter isotopes were mixed into the upper mantle during the first few days of Creation—and then later mixed into the earth’s crust during the flood. This would erroneously represent millions or billions of years of age.

The bottom line is this: Ancient and recent lava flows have the same chemistry derived from the earth’s upper mantle. P/D ratios have nothing to do with age of the rock—they are just ratios.

So the question is, why would evidence for accelerated decay be ignored or rejected by secular scientists? Although some are seeking the truth, many others just want to validate evolutionary doctrine. It is the same reason described in the last section, Why Do People Believe So Strongly in Evolution?—the term “supernatural” or the concept of God is considered to be outside the realm of real science. The bottom line is that all data must fit the evolutionary belief model—and that use of data is driven by an “old-earth” view that pervades academia today.