Relative age dating vs radiometric dating
A common form of criticism is to cite geologically complicated situations where the application of radiometric dating is very challenging.
These are often characterised as the norm, rather than the exception.
I thought it would be useful to present an example where the geology is simple, and unsurprisingly, the method does work well, to show the quality of data that would have to be invalidated before a major revision of the geologic time scale could be accepted by conventional scientists.
Geochronologists do not claim that radiometric dating is foolproof (no scientific method is), but it does work reliably for most samples.
In order for a layer of material to be deposited, something has to be beneath it to support it.
It can't float in mid-air, particularly if the material involved is sand, mud, or molten rock.
In this situation, the cave contents are younger than both the bedrock below the cave and the suspended roof above.
There are situations where it potentially fails -- for example, in cave deposits.To get to that point, there is also a historical discussion and description of non-radiometric dating methods.The example used here contrasts sharply with the way conventional scientific dating methods are characterized by some critics (for example, refer to discussion in "Common Creationist Criticisms of Mainstream Dating Methods" in the Age of the Earth FAQ and Isochron Dating FAQ).My thanks to both him and other critics for motivating me.Much of the Earth's geology consists of successional layers of different rock types, piled one on top of another.
It is not about the theory behind radiometric dating methods, it is about their , and it therefore assumes the reader has some familiarity with the technique already (refer to "Other Sources" for more information).