Rubidium strontium dating formula
It suffers from the problem that rubidium and strontium are very mobile and may easily enter rocks at a much later date to that of formation.
This method for rock dating is based on the decay of potassium-40 into argon: until the rock solidifies, argon can escape, so it can in theory date the formation of rock.
This leaves out important information which would tell you how precise is the dating result.
Carbon-14 dating has an interesting limitation in that the ratio of regular carbon to carbon-14 in the air is not constant and therefore any date must be calibrated using dendrochronology.
To date older fossils, other methods are used, such as potassium-argon or argon-argon dating.
Other forms of dating based on reactive minerals like rubidium or potassium can date older finds including fossils, but have the limitation that it is easy for ions to move into rocks post-formation so that care must be taken to consider geology and other factors.
One way Young Earth Creationists and other denialists try to discredit radiometric dating is to cite examples radiometric dating techniques providing inaccurate results. Helens, creationists attempted discredit the discipline through dishonest practices.
This is frequently because the selected technique is used outside of its appropriate range, for example on very recent lavas. The Institute for Creation Research's RATE project aimed to show scientifically that methods of radiometric dating produced wildly inconsistent and incorrect values.
A limitation with all forms of radiometric dating is that they depend on the presence of certain elements in the substance to be dated.
Radiometric dating — through processes similar to those outlined in the example problem above — frequently reveals that rocks, fossils, etc.
are very much older than the approximately 6,000 to 10,000 years reckoned by young earth creationists.
One problem is that potassium is also highly mobile and may move into older rocks.
This depends on the decay of uranium-237 and uranium-238 to isotopes of lead.
The oldest rock so far dated is a zircon crystal that formed 4.4-billion-years ago, which was only 200 million years or so after the Earth itself formed.