Here is a little problem (very minor indeed)...
"The new lava dome (dacite) from the at Mount St. Helens was formed in 1986. In 1997 five specimens were taken from this dome at five different locations and subjected to conventional Potassium-Argon dating. The results indicated ages of less than one half to almost three million years old, all from eleven year old rock." -
Unreliability of Radiometric Dating and Old Age of the Earth
Hmmm, that one doesn't get a lot of press from evolutionary proponents, does it?
From UNC...
"For this system to work as a clock, the following 4 criteria must be fulfilled:
1. The decay constant and the abundance of K40 must be known accurately.
2. There must have been no incorporation of Ar40 into the mineral at the time of crystallization or a leak of Ar40 from the mineral following crystallization.
3. The system must have remained closed for both K40 and Ar40 since the time of crystallization.
4. The relationship between the data obtained and a specific event must be known."
Now if there were a flood...
The University of North Carolina is not as sure as Jack and Absurd are about radiometric dating. More from this erudite institution...
The requirements for radiometric dating are stated in another way, at the web site
http://hubcap.clemson.edu/spurgeon/books/apology/Chapter7.html:
"But what about the radiometric dating methods? The earth is supposed to be nearly 5 billion years old, and some of these methods seem to verify ancient dates for many of earth's igneous rocks. The answer is that these methods, are far from infallible and are based on three arbitrary assumptions (a constant rate of decay, an isolated system in which no parent or daughter element can be added or lost, and a known amount of the daughter element present initially)."
Here are more quotes about radiometric dating from
http://www.parentcompany.com/handy_dandy/hder12.htm:
"All of the parent and daughter atoms can move through the rocks. Heating and deformation of rocks can cause these atoms to migrate, and water percolating through the rocks can transport these substances and redeposit them. These processes correspond to changing the setting of the clock hands. Not infrequently such resetting of the radiometric clocks is assumed in order to explain disagreements between different measurements of rock ages. The assumed resettings are referred to as `metamorphic events' or `second' or `third events.' "
And again,
"It is also possible that exposure to neutrino, neutron, or cosmic radiation could have greatly changed isotopic ratios or the rates at some time in the past."
It is known that neutrinos interact with atomic nucleii, so a larger density of neutrinos could have sped up radioactive decay and made matter look old in a hurry. Some more quotes from the same source:
a. In the lead-uranium systems both uranium and lead can migrate easily in some rocks, and lead volatilizes and escapes as a vapor at relatively low temperatures. It has been suggested that free neutrons could transform Pb-206 first to Pb-207 and then to Pb-208, thus tending to reset the clocks and throw thorium-lead and uranium-lead clocks completely off, even to the point of wiping out geological time. Furthermore, there is still disagreement of 15 percent between the two preferred values for the U-238 decay constant.
b. In the potassium/argon system argon is a gas which can escape from or migrate through the rocks. Potassium volatilizes easily, is easily leached by water, and can migrate through the rocks under certain conditions. Furthermore, the value of the decay constant is still disputed, although the scientific community seems to be approaching agreement. Historically, the decay constants used for the various radiometric dating systems have been adjusted to obtain agreement between the results obtained. In the potassium/argon system another adjustable "constant" called the branching ratio is also not accurately known and is adjusted to give acceptable results.
Argon-40, the daughter substance, makes up about one percent of the atmosphere, which is therefore a possible source of contamination. This is corrected for by comparing the ratio argon-40/argon-36 in the rock with that in the atmosphere. However, since it is possible for argon-36 to be formed in the rocks by cosmic radiation, the correction may also be in error. Argon from the environment may be trapped in magma by pressure and rapid cooling to give very high erroneous age results. In view of these and other problems it is hardly surprising that the potassium/argon method can yield highly variable results, even among different minerals in the same rock.
c. In the strontium/rubidium system the strontium-87 daughter atoms are very plentiful in the earth's crust. Rubidium-87 parent atoms can be leached out of the rock by water or volatilized by heat.
All of these special problems as well as others can produce contradictory and erroneous results for the various radiometric dating systems. " -
The Radiometric Dating Game
But don't worry, just swallow the theory without question, it has to be right because these learned individuals tell us so. Funny, the learned individuals also used to prescribe blood letting, thought disease was caused by "bad humors" and prescribed concoctions such as Radithor.